WO2008041714A1 - Charging device, and its manufacturing method - Google Patents

Charging device, and its manufacturing method Download PDF

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Publication number
WO2008041714A1
WO2008041714A1 PCT/JP2007/069315 JP2007069315W WO2008041714A1 WO 2008041714 A1 WO2008041714 A1 WO 2008041714A1 JP 2007069315 W JP2007069315 W JP 2007069315W WO 2008041714 A1 WO2008041714 A1 WO 2008041714A1
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WIPO (PCT)
Prior art keywords
negative electrode
storage device
positive electrode
charge
voltage
Prior art date
Application number
PCT/JP2007/069315
Other languages
French (fr)
Japanese (ja)
Inventor
Masakazu Tanahashi
Hiroe Kondo
Hideya Yoshitake
Tetsuo Yamada
Shinichi Ishitobi
Original Assignee
Ube Industries, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2006272317A external-priority patent/JP4863000B2/en
Priority claimed from JP2006272318A external-priority patent/JP4863001B2/en
Application filed by Ube Industries, Ltd. filed Critical Ube Industries, Ltd.
Publication of WO2008041714A1 publication Critical patent/WO2008041714A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/46—Accumulators structurally combined with charging apparatus
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a power storage device, a power storage system, an electronic device using the same, and a power system that have a high voltage, a large capacity, and high reliability in a charge / discharge cycle.
  • a power storage device using a non-aqueous electrolyte there are a lithium ion secondary battery and an electric double layer capacitor.
  • lithium ion secondary batteries a lithium-containing transition metal oxide is used for the positive electrode, and a graphite-based carbon compound capable of intercalating lithium is preferably used for the negative electrode.
  • a non-aqueous electrolyte containing is used.
  • lithium-ion secondary batteries usually use a lithium-containing transition metal oxide for the positive electrode, the lithium-ion secondary battery can realize charging and discharging at a high voltage, resulting in a high-capacity battery.
  • the positive and negative electrode active materials themselves occlude and desorb lithium ions, resulting in early deterioration of the charge / discharge cycle.
  • the electric double layer capacitor is composed of a polarizable electrode mainly composed of activated carbon for both the positive electrode and the negative electrode, it enables rapid charge and discharge even though the capacity is low, and in the charge and discharge cycle. High level and reliability can be secured.
  • Patent Document 1 proposes a special carbon material used as an electrode material for an electric double layer capacitor and a method for manufacturing the same.
  • Patent Document 2 the half-value width in the X-ray diffraction of the (002) peak is 0.5 to 5.0.
  • An electric double layer capacitor containing the graphite-based carbon material as the main component of both the positive electrode and the negative electrode has been proposed, but as shown in the examples, after the electric double layer capacitor was fabricated, Instead of activation treatment, use a high voltage of 3.8V for 20 minutes to 5 hours.
  • Patent Document 3 uses an electric power in which boron-containing graphite obtained by heat treatment of a carbon material containing boron or a boron compound is used as the positive electrode carbon material, and activated carbon is used as the negative electrode carbon material. Double layer capacitors have been proposed. Patent Document 3 does not disclose details of the force S for estimating the anion intercalation reaction at the positive electrode and the charge / discharge process. Details regarding physical properties such as specific surface area of boron-containing graphite have also been clarified!
  • Patent Document 4 also proposes an electric double layer capacitor using graphite as a positive electrode active material and using graphite or activated carbon as a negative electrode active material! It is said that it is expressed by the adsorption and desorption of ions at the negative electrode.
  • Patent Document 1 Japanese Patent Laid-Open No. 10-199767
  • Patent Document 2 JP 2002-151364 A
  • Patent Document 3 Japanese Unexamined Patent Application Publication No. 2004_134658
  • Patent Document 4 Japanese Patent Laid-Open No. 2005-294780
  • the present invention relates to a conventional lead battery, lithium ion secondary battery, nickel metal hydride secondary battery, electric
  • An object of the present invention is to provide an electricity storage device that can replace a multilayer capacitor and the like, has a substantially large storage capacity and energy capacity, and has high reliability in a charge / discharge cycle.
  • the present invention relates to a first mode in which the negative electrode is reversely charged with a positive charge during complete discharge (hereinafter referred to as mode A), and charging with a negative charge remaining without discharging the negative electrode during complete discharge. It includes two embodiments of the second embodiment (hereinafter referred to as embodiment B).
  • a of the present invention is characterized by the following matters.
  • An electricity storage device including a positive electrode and a negative electrode containing a carbonaceous active material, wherein the electrical charging process at the positive electrode comprises the adsorption process of ayuon in the low voltage region and the intercalation process in the high voltage region.
  • a storage device wherein the negative electrode is reversely charged with a positive charge when fully discharged.
  • the positive electrode and the negative electrode are set so that the negative electrode potential exceeds the irreversible reaction potential at the negative electrode before the positive electrode reaches the maximum allowable amount of electricity during initial charging,
  • the operating voltage range of the negative electrode is expanded by 10% or more of the operating voltage range based on cation adsorption inherent in the negative electrode, as described in any one of 1 to 3 above Power storage device.
  • the cumulative chargeable capacity of the negative electrode contributes to the cation adsorption inherent in the negative electrode. 4.
  • a graphite material is used as an active material of the positive electrode
  • the positive electrode potential during charging is 5.2 Vvs. Li +
  • the power storage device according to any one of 1 to 9 above, which is used in a range not exceeding / Li.
  • a method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material
  • a method for producing an electricity storage device comprising performing at least one open charge and open charge at a voltage at which an irreversible reaction occurs at the negative electrode.
  • aspect B of the present invention is characterized by the following matters.
  • An electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material, wherein the electrical charging process at the positive electrode comprises an adsorption process of ayuons in a low voltage region and an intercalation process in a high voltage region.
  • An electricity storage device wherein the negative electrode is charged with a negative charge remaining without being discharged at the time of complete discharge.
  • the positive electrode and the negative electrode must be connected before the negative electrode reaches the maximum allowable amount of electricity during initial charging.
  • the positive electrode potential is set to exceed the irreversible reaction potential at the positive electrode
  • the electricity storage device which is produced by performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
  • a graphite material is used as an active material of the positive electrode
  • the positive electrode potential during charging is 5.2 Vvs. Li +
  • a method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material
  • the electrical charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region
  • the electrical charging at the negative electrode occurs due to the adsorption of 1S cations
  • the initial stage Set the capacities of the positive and negative electrode materials so that the positive electrode potential exceeds the irreversible reaction potential at the positive electrode before the negative electrode reaches the maximum allowable amount of electricity during charging.
  • a method for manufacturing an electricity storage device comprising performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
  • the present invention while maintaining the characteristic of high-speed charge / discharge characteristic of a non-aqueous electric double layer capacitor, it can be used at a higher voltage than a conventional electric double layer capacitor. It is possible to provide an electricity storage device with high reliability in a charge / discharge cycle in which the electricity storage capacity and energy capacity that can be used qualitatively are large.
  • the charging / discharging process is a two-stage process of reversible adsorption and reversible intercalation of the cation on the positive electrode active material, so that the decomposition reaction of the electrolytic solution is suppressed during device use.
  • a high-capacity storage device particularly a high-energy storage device, using the intercalation region.
  • the electricity storage device of the present invention does not fall within the category of an electric double layer capacitor in which the electrolyte is adsorbed on the polarizable electrode and develops capacity, but can be charged / discharged more rapidly than a conventional battery.
  • the negative electrode is reversely charged with a positive charge during complete discharge. This means that in addition to the electric capacity expressed by the adsorption capability inherent in the negative electrode, an electric capacity corresponding to the positively charged positive charge can be stored and discharged. For this reason, according to this aspect, a high capacity
  • activated carbon having a large surface area is also used in one method. Since the surface area and the electrode density are in a contradictory relationship, the power storage device that emphasizes the capacity per volume is important. This is probably the best way!
  • a method for modifying a low surface area activated carbon to an activated carbon for a capacitor by performing an electrochemical operation in the assembled device is known as a nanogate capacitor (JP 2002-0225867, etc.).
  • the modification of the activated carbon in the nanogate capacitor is to expand the carbon layer by intercalating ions between the coater carbon layers during charging, and use the expanded carbon layer as an ion adsorption site.
  • the increase in the capacity of the negative active carbon of this embodiment A does not involve the modification of the surface area by adding an electrochemical treatment to the activated carbon. It increases the ion adsorption capacity of activated carbon, which expands the adsorption capacity not only to cations but also to anions, in other words, the adsorption utilization rate of ions.
  • the activated carbon may be a commercially available activated carbon, and the capacity balance between the positive electrode and the negative electrode may be adjusted.
  • the activated carbon is simply performed as a device stabilization process! /, Capacity of activated carbon as a conventional negative electrode active material by controlling the conditions of open charge Can be raised from 20% to 50%.
  • the negative electrode is in a state of being charged with a negative charge remaining without being discharged, so the isoelectric point is shifted to the low potential side, and as a result, the positive electrode is The transition voltage that changes from V-ion adsorption to intercalation increases. Therefore, the power storage device of the present aspect B has a high operating voltage and a capacity in a high voltage range that is pulled up. Furthermore, it is possible to reduce the load of anion intercalation on the positive electrode in the low voltage range that is not practically used.
  • the electricity storage device of the present embodiment B has high voltage, high capacity, and good cycle characteristics.
  • the power storage device of the present embodiment B can obtain a high operating voltage of 1.75V power, 3.5V, etc.
  • the power storage device of the present embodiment B can be used in a field where rapid charge and discharge is performed at a high voltage.
  • the chair features are effective, and can be used, for example, as an engine starter power supply or a HEV storage device.
  • the power required for a storage device for HEV that requires a voltage of 200V or higher Compared to conventional electric double layer capacitors, the number of devices in series is reduced by 40%. This not only has the effect of simplifying the booster circuit, but also has the merit of reducing the failure frequency because all energy in the series part cannot be obtained if one device fails because of the series.
  • FIG. 1-1 is a diagram showing an electricity storage device before charging.
  • (A) is a schematic diagram for showing the relationship between positive and negative electrode capacities, potentials, and voltages, where the horizontal axis represents the potential and the vertical axis represents the capacitance (dQ / dV).
  • (B) is a schematic diagram of a battery configuration for showing a charge balance between a positive electrode and a negative electrode.
  • FIG. 1-2 A diagram showing an electricity storage device in a state of being charged. Refer to the explanation in Fig. 11 for the explanation of (A) and (B).
  • FIG. 1-3 A diagram showing an electricity storage device in a state where the negative electrode has reached a chargeable integrated capacity.
  • (A) and (B) see the explanation of Fig. 11.
  • FIG. 1-4 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs due to overcharge.
  • (A) and (B) see the explanation of Fig. 11.
  • FIG. 1-5 It is a diagram showing an electricity storage device in a state of being discharged to an initial isoelectric point. Refer to the explanation of Fig. 11 for the explanation of (A) and (B).
  • FIG. 1-6 is a diagram showing the electricity storage device in a fully discharged state.
  • FIG. 11 For the explanation of (A) and (B), see the explanation of Fig. 11.
  • FIG. 1_7 A diagram showing an electricity storage device in a state where an irreversible reaction occurs due to the second overcharge! See the description of Figure 1-1 for an explanation of (A) and (B).
  • FIG. 1-8 is a diagram showing an electricity storage device that has been completely discharged after the second overcharge. See the description of Figure 11 for an explanation of (A) and (B).
  • Example A Draw a graph indicating the characteristics of the electricity storage device during the first and tenth charging in Example 1.
  • FIG. 1-11 This is a graph schematically showing the voltage dependence of capacitance in an actual device.
  • FIG. 1-13 Storage device when open charge / discharge is repeated to overcharge voltage in Example A-2 1-15] Diagram for explaining the limit charge potential and inter-terminal voltage of the storage device when in use It is. See the description of Figure 1-1 for an explanation of (A) and (B).
  • FIG. 2-1 is a diagram showing an electricity storage device before charging.
  • (A) is a schematic diagram for showing the relationship between positive and negative electrode capacities, potentials, and voltages, where the horizontal axis represents the potential and the vertical axis represents the capacitance (dQ / dV).
  • FIG. 2-1 is a schematic diagram of a battery configuration for showing a charge balance between a positive electrode and a negative electrode.
  • FIG. 2-2 is a diagram showing the electricity storage device in a state of being charged. For the explanation of (A) and (B), see the explanation of Figure 2-1.
  • FIG. 2-3] is a diagram showing the electricity storage device in a state where the accumulated capacity that can be charged by the positive electrode has been reached. See the description of Figure 21 for an explanation of (A) and (B).
  • FIG. 2-4 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs at the positive electrode due to overcharge. For the explanation of (A) and (B), see the explanation of Fig. 21.
  • FIG. 2-5 is a diagram showing the electricity storage device in a state where it has been discharged to the initial isoelectric point. Refer to the explanation of Fig. 21 for explanation of (A) and (B).
  • FIG. 2-6 is a diagram showing an electricity storage device in a completely discharged state. See the description of Figure 21 for an explanation of (A) and (B).
  • FIG. 2-7 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs due to the second overcharge!
  • FIG. 2-7 For the explanation of (A) and (B), see the explanation of Fig. 21.
  • FIG. 2-8 is a diagram showing an electricity storage device that has been completely discharged after the second overcharge.
  • FIG. 2-8 For the explanation of (A) and (B), see the explanation of Fig. 21.
  • Fig. 2-9 This is a graph showing the characteristics of the electricity storage device when open charge / discharge is repeated up to the overcharge voltage up to 5 times in Example B-1.
  • Fig. 2-10 This is a graph showing the characteristics of the electricity storage device when open charge / discharge is repeated up to the overcharge voltage up to 5 times in Example B-2.
  • FIG. 2-14 is a diagram for explaining the limit charging potential and the terminal voltage of the electricity storage device during use. See the description of Figure 1 for a description of (A) and (B).
  • FIG. 3 is a graph showing the relationship between charge / discharge capacity and voltage of an electricity storage device to which the present invention is applied.
  • the negative electrode in order to be in a state where the negative electrode is reversely charged with a positive charge at the time of complete discharge (Aspect A), or at the time of complete discharge, the negative electrode is charged with a remaining negative charge without being discharged.
  • A positive charge at the time of complete discharge
  • B the state where an irreversible reaction as described later is used.
  • the electrical charging process at the positive electrode shows the adsorption process of the anion in the low voltage region and the intercalation process in the high voltage region.
  • FIG. 3 shows typical charge / discharge characteristics of the electricity storage device of the present invention.
  • Fig. 4 shows the charge / discharge characteristics of a device using activated carbon for the positive and negative electrodes as a conventional electric double layer capacitor, together with the characteristics of the device of the present invention shown in Fig. 3.
  • the horizontal axis represents the charge / discharge capacity
  • the vertical axis represents the voltage. For example, if constant current charging is performed, the horizontal axis represents the charging capacity and also corresponds to the charging time.
  • the slope of the charge capacity voltage characteristic curve changes greatly with voltage Vt as the boundary during charging. That is, the ionic salt anion is adsorbed on the positive electrode active material up to the voltage Vt, and the anion is inter-forced on the positive electrode active material at a voltage Vt or higher.
  • the voltage Vt at which the charging process changes from adsorption to intercalation is defined as the transition voltage.
  • the charge capacity is small because the amount of cation adsorbed on the positive electrode active material having a small specific surface area is small. A large slope is observed in the voltage characteristic curve. In the subsequent charging process using intercalation, a large charge with a relatively small change in voltage can be taken in.
  • the electricity storage device of the present invention is preferably used in an intercalated state as a charge / discharge region during use.
  • the force s indicates that it can be used up to 1.5V, which is lower than the transition voltage Vt during discharge. Even in this state, the intercalated anion remains, and recharging starts from here. In this case, charging starts from the transition voltage Vt or higher without going through the adsorption process.
  • the difference between the transition voltage Vt at the time of charging and the voltage that can be used in the intercalation state at the time of discharging is usually about 0.5 V due to the influence of the current and internal resistance during charging and discharging.
  • the electricity storage device of the present invention discharge is performed while maintaining a high voltage during the discharge as described above, and thus the electricity storage capacity that can be actually used is large in the voltage range required for the electronic device.
  • the energy capacity that can be extracted corresponds to the integration of the chronopotentiogram, but the device of the present invention is also characterized by a large energy capacity because it discharges at a high voltage.
  • the chronopotentiogram of charge / discharge is gentle. This indicates that the capacity to be charged is large even at a low voltage.
  • the capacity that can be used in the range of 1.5 V or less is large in this example.
  • the electricity storage device of the present invention is characterized by a large charge capacity, particularly an energy capacity, in a relatively high voltage range that is actually used.
  • the transition voltage Vt of the electricity storage device of the present invention is preferably set in consideration of the voltage used in an actual electronic device, and is usually preferably set to 1.5 V or higher.
  • the transition voltage Vt depends on the capacity of the positive electrode active material and the capacity of the negative electrode active material, particularly the ratio thereof, the transition voltage Vt can be adjusted by a combination of both. . When the capacity of the positive electrode active material is large, the transition voltage Vt is low, and when the capacity of the negative electrode active material is large, the transition voltage Vt is high.
  • the electricity storage device of the present invention for example, by adjusting the capacities of the positive electrode active material and the negative electrode active material, that is, by adjusting the transition voltage Vt, during charging (that is, interaction with the positive electrode active material).
  • the decomposition reaction of the electrolyte in the positive electrode can be suppressed, and the cycle characteristics can be improved.
  • the inventor decomposes the electrolytic solution (solvent) on the positive electrode, and the organic substance of the decomposition products accompanying this decomposition moves to the negative electrode side.
  • the starting voltage for the decomposition of the electrolyte depends on various factors, such as the type and surface area of the activated carbon, and the capacity ratio between the positive and negative electrodes. In this example of the electricity storage device of the present invention, about 3.2 V (Fig. 3), while in the conventional electric double layer capacitor, a decomposition reaction current is observed from about 2.3 V (Fig. 4), respectively! /, The
  • the capacitance ratio between the negative electrode and the positive electrode is reduced, and the transition voltage is set low. While the charging capacity increases, charging can be performed up to a range where the absolute value of the negative electrode potential is small and the increase in the positive electrode potential is small. As a result, even if the usable voltage range of the electricity storage device is widened, it can be used within a potential where the electrolyte decomposition reaction is sufficiently suppressed. As described above, charging in the positive electrode active material shows a two-stage process of adsorption and intercalation, so that the electricity storage device of aspect A can take a large discharge capacity and discharge energy. Considering the decomposition of the electrolyte during use, this electricity storage device is extremely excellent in terms of the discharge capacity and discharge energy that can be used in actual equipment and the cycle characteristics!
  • the capacitance ratio between the negative electrode and the positive electrode is increased to set the transition voltage high. While the charging capacity increases, the negative electrode power Charging is possible up to a range with a large absolute value. As a result, the resolved voltage as viewed from the device voltage increases. Therefore, in addition to the increase in the usable voltage of the electricity storage device, it can be used in a voltage range in which the electrolytic solution decomposition reaction is sufficiently suppressed. Under such conditions of use, the deposition of organic matter on the negative electrode is suppressed and the capacity reduction of the electricity storage device is improved, resulting in improved cycle characteristics. Specifically, in FIGS.
  • the charge / discharge capacity that can be used in the electricity storage device is in the range of 3.2 V to; 1.5 V, so 2.3 V to 1; It exceeds the charge / discharge capacity of electric double layer capacitors that can only be used in the 5V range. Furthermore, when compared with the discharge energy, the storage device that shows the sequential charging process is more than three times the electric double layer capacitor.
  • aspect B by showing the two-stage process of charging power adsorption and intercalation in the positive electrode active material as described above, by setting the transition voltage Vt relatively high, it is possible to An electricity storage device can increase the available discharge capacity and discharge energy. Furthermore, considering the decomposition of the electrolyte, this storage device having a transition voltage is extremely excellent in terms of discharge capacity and discharge energy that can be used in an actual apparatus, and cycle characteristics.
  • the capacity expansion in the embodiment A of the present invention is to increase the ion utilization rate of the activated carbon of the negative electrode. This mechanism will be explained with reference to Fig. 1-1 to Fig. 1-8.
  • (A) and (B) show the same charge / discharge state
  • (A) is a schematic diagram showing the relationship between the capacity and potential of positive and negative electrodes, voltage, and the horizontal axis is potential
  • the vertical axis represents the capacitance (dQ / dV).
  • (B) is a schematic diagram of the battery structure, and describes the electrons and holes held by the positive electrode and the negative electrode, and the charge balance.
  • FIG. 11 shows the electricity storage device before charging.
  • the anions and cations were not intercalated or adsorbed on the positive and negative electrodes.
  • the squares of the positive and negative electrodes are the height of the capacitance, the potential position in the horizontal position is the chargeable range, and the area of the square is the accumulated capacity of each (the integrated electric charge that can be charged by normal charging) mAH) is schematically represented.
  • the capacity of the positive electrode is the sum of the adsorption capacity and intercalation capacity.
  • FIG. 12 (B) shows the state where the positive and negative electrode capacities were partially charged.
  • FIG. 13 (B) N electrons flow in the negative electrode due to the positive force, N electrons accumulate in the negative electrode, and N holes accumulate in the positive electrode.
  • FIG. 13 (A) the accumulated capacity of the negative electrode is fully charged, but the chargeable capacity still remains in the positive electrode (“extra portion” in the figure).
  • Such a state can be achieved by setting the accumulated capacity of the positive electrode to be larger than the accumulated capacity of the negative electrode.
  • the positive electrode cumulative capacity / negative electrode cumulative capacity ratio is preferably in the range of 1.;! ⁇ 2.0.
  • the effect of this aspect is exhibited even when the integrated capacity ratio exceeds 2.0, but when the integrated capacity ratio is 2.0 or more, the amount of the positive electrode active material not involved in charge / discharge becomes excessive, and the device capacity decreases.
  • the positive electrode integrated capacity / negative electrode integrated capacity ratio is 1.2 to 1.6.
  • the positive electrode cumulative capacity / negative electrode cumulative capacity ratio can be achieved by changing the weight ratio of the positive electrode and the negative electrode together with the selection of materials (selection of a material with a large capacity per unit weight or a small material).
  • the positive electrode potential is 5.5 V vs. Li + / Li or less (preferably 5.2 V or less), and the negative electrode potential is 1.9 V vs. Li + / Li.
  • the charging voltage between both electrodes is assumed to be 3.5V.
  • Figure 15 shows the state until the charged N electrons are discharged. Despite N + n electrons flowing on the negative electrode side, the number of electrons that can be discharged is N minus the amount of reaction current. N electrons flow into the positive electrode, leaving n holes on the positive electrode.
  • Figure 16 shows the fully discharged state. Assuming that the charge quantity of the n positive holes unevenly distributed in the positive electrode in Fig. 15 is Q, in the fully discharged state (Fig. 16), Q is distributed in proportion to the positive and negative electrostatic capacities. The potential is balanced. Let Cc be the electrostatic capacity of the adsorption part of the positive electrode, Vc be the distributed voltage, Ca be the electrostatic capacity of the adsorption part of the negative electrode, and Va be the distributed voltage.
  • the square height representing the capacity of the negative electrode is actually used as a negative electrode active material, as indicated by the height of the square representing the capacity due to adsorption of the positive electrode.
  • the capacitance of activated carbon is much larger than the capacitance of the adsorption part of graphite used as the positive electrode active material.
  • the capacity of the electricity storage device is calculated as the integration of the original negative electrode schematically shown by the negative electrode square in Fig. 11 (A).
  • Qa will increase the capacity that can be charged and discharged.
  • overcharging may be performed only once, but may be performed multiple times.
  • an example of continuing the second overcharge will be described.
  • the second overcharge the same operation as in the first overcharge is performed. Charge so that the irreversible reaction start potential (in this example, reductive decomposition potential of the solvent) is exceeded on the negative electrode side so that an irreversible reaction occurs even in the second overcharge.
  • the irreversible reaction start potential in this example, reductive decomposition potential of the solvent
  • the electrolyte will begin to decompose, ie overcharge.
  • m electrons are newly consumed for decomposition of the electrolyte
  • m holes are stored in the positive electrode. In this state, the number of electrons stored in the negative electrode is N, whereas the number of holes stored in the positive electrode is N + n + m.
  • m n may be satisfied.
  • FIG. 19 is a dQ / dV curve obtained from the charge / discharge curve in the electricity storage device of this embodiment, in which open charge / discharge by overcharge is repeated 10 times (Example A-1 described later).
  • the upper curve group shows the charging process
  • (1) shows the first charge
  • (10) shows the 10th charge.
  • the lower curve group shows the discharge process. From this figure, if charging and discharging are repeated within the range where irreversible reaction occurs, the voltage at which charging by intercalation starts at the positive electrode decreases (the rising voltage of the dQ / dV curve during charging decreases) .
  • the charge capacity is the integral value of the dQ / dV curve at the time of charge, so in a storage device that has been repeatedly overcharged 10 times, the charge capacity increases! .
  • the dQ / dV curve shows a specific shape based on the specific charge / discharge mechanism.
  • Figure 1-10 shows a graph of the dQ / dV curves extracted from the 1st overcharge and 10th overcharge processes from Figure 1-9.
  • the dQ / dV increases as the voltage rises after the curve rises.
  • the dQ / dV value gradually decreased immediately after the charge voltage V increased and the canyon intercalation at the positive electrode started, and then the dQ / dV value gradually decreased (in the figure).
  • dQ / dV increases gradually again after obtaining the minimum value. Since the electricity storage device of this embodiment is manufactured through open charge / discharge at a voltage at which an irreversible reaction occurs, the above-mentioned characteristic graph shape is observed even during the charge process during normal use.
  • the dQ / dV value is inevitably lowered after the start of charging.
  • the dQ / dV curve shows a characteristic shape in which the dQ / dV value gradually decreases after showing the maximum immediately after the start of intercalation.
  • do not overcharge at a voltage that causes an irreversible reaction! / Because the storage device has no decrease in dQ / dV value during charging as shown in Figure 111, it is monotonous even after the start of intercalation. The rise continues.
  • Figure 115 shows the limit charging potential and terminal voltage during actual use (steady state).
  • the “limit potential under charge” in the figure is the limit potential at which the reductive decomposition of the solvent begins. In this example, it is 1.7 Vvs. Li + / Li.
  • the “lower limit potential” is the lower limit potential when charging on the negative electrode side.
  • Charging potential of the negative electrode is specifically 1 ⁇ 7Vvs. Li + / Li or preferably tool particularly 1 ⁇ 9Vvs. Li + / Li or favored arbitrarily.
  • the “charging upper limit potential” in the figure is the lower one of the positive electrode potential at which the oxidative decomposition reaction of the solvent starts and the negative electrode potential when the negative electrode reaches the “lower charging limit potential”. In the example shown in FIG. 115, when the negative electrode reaches the “lower limit potential”, the positive potential reaches the “upper limit potential” of 4.9 Vvs. Li + / Li.
  • charging is performed at a positive electrode potential that does not cause the oxidative decomposition reaction of the solvent at least in a range where the positive electrode potential does not exceed the “limit potential for charging”.
  • the charge potential of the positive electrode is specifically 5. 2Vvs. Li + / Li in less good Mashigusa et 4. 9Vvs. Li + / Li or less. For example 4. 6 ⁇ 5 ⁇ 2Vvs. Use to be charged in a range of Li + / Li.
  • the charging voltage (voltage between the positive and negative terminals)
  • the voltage at which the electrolyte does not decompose is 3.5 V or less, preferably 3.4 V or less, more preferably 3.2 V or less. is there.
  • the capacity of the electricity storage device can typically be increased by about 10 to 60% compared to a device that does not perform the above treatment. In a preferred example, it is increased by about 15% to 50%.
  • the transition voltage at which the charging process at the positive electrode changes from adsorption to intercalation is high, and in the asymmetric electricity storage device, when an irreversible reaction occurs at the negative electrode, In order to store the charge related to the positive electrode and make the potential the same, it is possible to store a positive charge on the negative electrode by using a part of the transition voltage.
  • the power storage device of this embodiment can use a voltage with which a voltage (transition voltage) at which anion intercalation starts is about 1.5 to 2 V, and a voltage in a low voltage region.
  • a high transition voltage indicates that the operating voltage of the device of this mode is high and high energy. In this mode, the capacity is further increased by using a voltage section up to a lower voltage range. It is intended.
  • the operating voltage range of the negative electrode expanded according to this embodiment is preferably 10% or more of the operating voltage range based on the adsorption inherent in the negative electrode, more preferably 15% or more.
  • the energy increases by about 10 to 30%.
  • the transition voltage at which intercalation starts will decrease too much, so the transition voltage should be set to 1.5 V or higher, preferably 1.7 V or higher. Is preferred.
  • the operating voltage range of the expanding negative electrode is preferably 60% or less, more preferably 50% or less.
  • the case where the irreversible reaction occurs by reductive decomposition of the solvent is exemplified.
  • the reaction is not limited to the reductive decomposition of the solvent, and a reaction in which the irreversible reaction occurs at the negative electrode by overcharge can be used. In other words, any reaction that consumes electrons at the negative electrode without adversely affecting battery performance is acceptable.
  • the voltage for overcharging is appropriately determined depending on the voltage at which irreversible reaction occurs.
  • the decomposition voltage differs depending on the solvent, so it is preferable to determine it depending on the solvent components contained in the electrolyte.
  • overcharging for causing an irreversible reaction is divided into a plurality of times, it is possible to select milder conditions than in the case of obtaining a necessary capacity increase by one overcharging. Therefore, it is generally 2 times or more, preferably 5 times or more. Further, the number of times is not particularly limited, but it is preferably about 50 times or less for work.
  • Overcharging and discharging as described above are preferably performed in an open state before the device is completed as a product. Through these processes, the product electricity storage device is completed.
  • the electricity storage device of this aspect can be charged and discharged with high capacity, it is possible to store high energy. It can be used for backup power sources for personal computers, mobile phones, mobile mopile devices, and power sources for digital cameras.
  • the power storage device of this mode can also be applied to electric vehicles and HEV power systems.
  • the discharge voltage of the electricity storage device is preferably 1.5 V or higher, and more preferably 2 V or higher.
  • the power storage device of this aspect is combined with a known voltage control means that shuts down when the voltage decreases to a predetermined voltage so that only the charge / discharge power s intercalation region is present.
  • a known voltage control means that shuts down when the voltage decreases to a predetermined voltage so that only the charge / discharge power s intercalation region is present.
  • a system is also preferable.
  • the power storage device of this aspect is a known voltage control so that the terminal voltage is limited to a predetermined voltage range so that the positive electrode potential and the negative electrode potential are in the above-described range during charging in use. It is also preferable to combine the means into a power storage system.
  • the electricity storage device of the present aspect B further improves the electricity storage device having the above-described transition voltage, increases the transition voltage, and enables use at a higher voltage. Since the anion force force is a chemical reaction, the intercalation potential cannot be changed. Increasing the transition voltage means lowering the negative electrode potential at the start of positive electrode intercalation. In this embodiment B, since the negative electrode is charged with the remaining negative charge without being discharged, the potential of the negative electrode is lowered. Therefore, even when operated at a high voltage, the positive electrode does not reach the oxidative decomposition potential of the electrolytic solution, so that the cycle characteristics are improved.
  • a high transition voltage is preferred for a high voltage storage device 1. 75 V or more, preferably 2 V or more, more preferably 2.2 V or more.
  • the cycle characteristics are deteriorated due to excessive intercalation.
  • the anion intercalation with respect to the positive electrode in the low voltage range that is not practically used. Since the Chillon load can be reduced, the cycle characteristics by this mechanism can also be improved.
  • the active material of the positive electrode of this embodiment B a graphite material capable of intercalation of anion is typically used, and as the active material of the negative electrode, a cation can be adsorbed typically. Activated carbon is used. Expressing the intercalation capacity of the positive electrode as an electrostatic capacity, the electrostatic capacity of the positive electrode graphite is about 5 to 15 times that of activated carbon.
  • the electricity storage device of this embodiment B is a conventional electric double layer using activated carbon as an active material. Compared to capacitors, it is much higher! / And has a storage capacity.
  • the discharge capacity of this electricity storage device is determined by the amount of adsorption of the cations polarized on the negative electrode on the activated carbon and the amount of anion intercalated into the graphite.
  • the amount of anion to be intercalated is the same amount of electricity as the negatively polarized cation, it can be said that the device capacity is determined by the capacity of the negative electrode that polarizes the electrolyte. Therefore, activated carbon having the highest capacity should be selected for the electricity storage device of this embodiment B.
  • FIG. 1 The mechanism for increasing the voltage in Mode B will be described with reference to Figs. 2-1 to 2-8.
  • (A) and (B) show the same state
  • (A) is a schematic diagram showing the relationship between the capacity and potential of positive and negative electrodes, voltage
  • the horizontal axis is the potential
  • the vertical axis represents the capacitance (dQ / dV).
  • (B) is a schematic diagram of the battery structure, and explains the electrons and holes held by the positive electrode and the negative electrode, and the charge balance.
  • oxidative decomposition of the solvent is taken as an example.
  • the oxidation potential of the solvent is on the high potential side and the reduction potential of the solvent is on the low potential side.
  • Fig. 2-1 shows the electricity storage device before charging.
  • the anions and cations were not intercalated or adsorbed on the positive and negative electrodes.
  • the squares of the positive and negative electrodes are the height of the capacitance, the potential range in the horizontal position is charged, and the area of the square is the integrated capacity of each (integrated electric charge that can be charged by normal charging).
  • the quantity mAH) is schematically represented.
  • the positive electrode capacity is the adsorption capacity. And the sum of the two intercalation capacities.
  • FIG. 2 (B) shows the state where the positive and negative electrode capacities were partially charged.
  • N electrons flow to the negative electrode, and the negative electrode accumulates N electrons and adsorbs N charged cations to the positive electrode.
  • N holes accumulate, anions with N charges intercalate! /.
  • the accumulated capacity of the positive electrode is fully charged, but there is still a chargeable capacity remaining on the negative electrode! Part ").
  • Such a state can be achieved by setting the accumulated capacity of the negative electrode to be larger than the accumulated capacity of the positive electrode.
  • a preferable range of the positive electrode capacity / negative electrode capacity ratio is 0.5 to 0.95. Even if the capacity ratio is less than 0.5, the effect of the present embodiment B is exhibited, but if the number of the negative electrode is excessive, the capacity reduction is increased, so 0.5 or more is preferable. When the capacitance ratio is 0.95 or more, the transition voltage shift tends to be insufficient in terms of the effect of higher voltage. A more preferable positive electrode capacity / negative electrode capacity ratio is 0.75-0.9.
  • the positive electrode potential is 5.2 V vs. Li + / Li or more (preferably 5.5 V or more) and the negative electrode potential is 1.9 V vs. Li + / Li or more, depending on the solvent system used.
  • the voltage between the two electrodes By setting the voltage between the two electrodes to 3.4 V, preferably 3.5 V or more, an irreversible decomposition reaction of the electrolyte occurs on the surface of the positive electrode. Therefore, as shown in Fig. 2-4, if the charging voltage between the two electrodes is set to 3.5 V, the battery device of this mode B, which is designed to have a negative electrode capacity larger than the positive electrode capacity, is overcharged and the electrolyte solution at the positive electrode. Oxidative decomposition occurs, and n holes are consumed at the positive electrode (n electrons are absorbed). At this time, equivalent n electrons are stored in the negative electrode.
  • Figure 2-5 shows a state where N charged electrons are discharged. N electrons flow into the positive electrode, and the positive electrode is electrically neutral and has no charge. n electrons are stored. However, in this state, the potential of the positive electrode is still slightly high, and the potentials of the positive electrode and the negative electrode are not balanced.
  • the capacity of the negative electrode is set to be sufficiently larger than that of the positive electrode, so that the decrease in capacity does not affect the capacity of the entire battery.
  • the equipotential point shifts to the lower potential side by Va. Therefore, when charging is performed, charging starts from a low potential by Va from the beginning, so that the positive intercalation start voltage (transition voltage Vt) increases by Va. Therefore, the electricity storage device of this aspect B can be charged and discharged at a high voltage.
  • overcharging may be performed only once, but may be performed a plurality of times.
  • an example of the second overcharge will be described.
  • the second charge the same operation as the first charge is performed.
  • the irreversible reaction initiation potential on the positive electrode side (in this example, the oxidation of the solvent) Charge to exceed the decomposition potential.
  • the electrolyte will be decomposed, that is, overcharge will begin.
  • m positive holes are newly consumed for the decomposition of the electrolyte at the positive electrode (absorption of m electrons)
  • m electrons are stored at the negative electrode.
  • there are N holes accumulated in the positive electrode whereas N + n + m electrons are accumulated in the negative electrode.
  • m n may be satisfied.
  • the transition voltage at which the electrical process changes from adsorption to intercalation changes to the high voltage side by Va + Va.
  • the “lower charging potential” in the figure is the higher of the negative electrode potential at which the reductive decomposition of the solvent begins or the negative electrode potential when the positive electrode reaches the “upper charging limit potential”.
  • 1.7 Vvs. Li + / Li is shown as an example where they are exactly equal.
  • Negative electrode charging The electric potential is preferably 1.7 Vvs. Li + / Li or more, particularly preferably 1 ⁇ 9 Vvs. Li + / Li or more.
  • the charging voltage (voltage between the positive and negative terminals)
  • the voltage at which the electrolyte does not decompose is 3.5 V or less, preferably 3.4 V or less, more preferably 3.2 V or less. is there.
  • the transition voltage of the electricity storage device increases by about 0.5V, or 1.5V.
  • an electrical storage device having a high transition voltage can be obtained by performing one or more open charge / discharge cycles at a voltage at which an irreversible reaction occurs on the positive electrode side.
  • a high transition voltage means that the operating voltage of the device is high and high energy.
  • the force by which the negative electrode capacity is gradually reduced by the treatment of the present embodiment B This decrease in capacity is a decrease in capacity in a low voltage operation region of 2 V to 2.2 V or less in the storage device of the present embodiment B. Therefore, there is no change in the capacity in the practical high voltage range. In other words, when charging / discharging in the low voltage range from 0V to 1.75V to 2V, the capacity appears to decrease in capacity.
  • a material that decomposes at the positive electrode during overcharge may be added in advance.
  • the electric capacity that decomposes at the positive electrode during open charge can be stored at the negative electrode, and the transition voltage can be increased by the potential corresponding to the charge. This method is effective in improving cycle characteristics because no excessive anion intercalation is performed on the positive electrode.
  • the voltage for overcharging is appropriately determined depending on the voltage at which the irreversible reaction occurs.
  • the decomposition voltage differs depending on the solvent, so it is preferable to determine it depending on the solvent component contained in the electrolyte.
  • the overcharge for causing the irreversible reaction is divided into multiple times, it is possible to select milder conditions than when obtaining the required capacity increase with a single overcharge. Therefore, it is generally 2 times or more, preferably 5 times or more. Further, the number of times is not particularly limited, but it is preferably about 50 times or less for work.
  • the overcharge and discharge as described above are preferably performed in an open state before the device is completed as a product. Through these processes, the product electricity storage device is completed.
  • the electricity storage device of the present aspect B operates even at a high voltage of 3 V or more, and can be charged and discharged with a high capacity, and thus can store high energy. Its use can be used for PC backup power supplies, mobile phones, portable mopile devices, and digital camera power supplies. In addition, the electricity storage device of aspect B can also be applied to electric vehicles and HEV power systems.
  • the power storage device according to the present aspect B is combined with a known voltage control unit that shuts down when the voltage decreases to a predetermined voltage so that charging / discharging is performed only in the intercalation region.
  • a known voltage control unit that shuts down when the voltage decreases to a predetermined voltage so that charging / discharging is performed only in the intercalation region.
  • a system is also preferable.
  • the electricity storage device of the present aspect B is publicly known to limit the inter-terminal voltage to a predetermined voltage range so that the positive electrode potential and the negative electrode potential are in the above-mentioned range during charging during use. It is also preferable to combine with other voltage control means to make a power storage system! /.
  • the electricity storage device of the present invention materials such as a positive electrode active material, a negative electrode active material, a binder, a conductive material, a current collector, a separator, and an electrolytic solution are used.
  • materials such as a positive electrode active material, a negative electrode active material, a binder, a conductive material, a current collector, a separator, and an electrolytic solution are used.
  • Examples of the shape of the electricity storage device include a winding type, a stack type, and a twist.
  • any conventional technology such as EcaSS (trademark) can be suitably used as a system for extracting electric capacity.
  • graphite means a hexagonal network plane with SP2 hybrid orbital carbon atoms, and this two-dimensional lattice structure is regularly stacked as a basic structural unit (crystallite). Good thing, has strong anisotropy.
  • Graphite material means that graphite is sufficiently generated. In the present application, black lead is included.
  • a carbon material is used as an active material for both the positive electrode and the negative electrode.
  • the active material for the positive electrode include graphite materials.
  • the graphite material used as the positive electrode active material may be either natural graphite or artificial graphite. When obtaining a higher capacity, it is preferable to use highly crystalline graphite. In order to achieve good intercalation, the interlayer distance of the graphite material is preferably 0.3357 nm or less, more preferably 0.3355 nm or less.
  • the crystal structure of graphite material includes hexagonal structure ( ⁇ ⁇ stacking period) and rhombohedral structure (ABCABC “stacking period).
  • rhombohedral structure is introduced by grinding.
  • graphite having no rhombohedral structure is preferable.
  • the outer surface area of the graphite material particles is preferably larger, that is, the more preferable (that is, the smaller the graphite particles, the more preferable it is).
  • the rhombohedral structure is often introduced, and the crystallinity of the graphite material is often impaired. Therefore, the average particle diameter of the preferable black lead material is 3 to 40 m, and more preferably 6 to 25 m.
  • the specific surface area of the graphite material for example, when a rhombohedral structure is not introduced using a jet mill or the like, and the powder is pulverized while maintaining the crystallinity of the graphite material, the specific surface area; ! ⁇ 20m 2 / g can be adjusted to S, 10m 2 / g or less, more preferably 2 to 5m 2 / g in order to lower the decomposition rate of the solvent on the positive electrode surface. preferable.
  • the tap density of the consolidated graphite is 0 ⁇ 8 ⁇ ;! ⁇ 4 g / cc, and the true density is 2.2 ⁇ 22 g / cc or more.
  • the ratio of the graphite material of 1 ⁇ m or less is substantially 10% or less, the decrease in the bulk density of the graphite is suppressed and the increase in the surface area is also suppressed.
  • the carbon-based material used as the negative electrode active material it is preferable to select a material that only adsorbs ions during charging and discharging, that is, a material that does not generate intercalation. Quality materials. Material with a larger specific surface area than the active material of the positive electrode Is preferred. When using a graphite material, a material different from the material of the active material of the positive electrode is preferred, and a material having a specific surface area larger than that of the graphite material used for the positive electrode is selected. As the activated carbon, known activated carbon for capacitors can be used.
  • chemical activated coconut shell activated carbon for example, chemical activated coconut shell activated carbon, steam activated coconut shell activated carbon, phenol resin activated carbon and pitch activated carbon, or alkali activated phenol resin activated carbon and mesophase pitch activated carbon can be used.
  • high surface area black lead material for example, high surface area black lead material, CVD-treated activated carbon or graphite material can also be used.
  • Carbonaceous material used as the active material of the negative electrode the specific surface area is 300 meters 2 / g or more preferably has a high surface area of good Mashigu particularly 450m 2 / g ⁇ 2000m 2 / g. Normally, it is preferable to use activated carbon as the negative electrode active material, but when high density storage capacity per volume is desired, high surface area graphite material can be compacted to increase bulk density, which is preferable. It is.
  • the binder is not particularly limited, and PVDF, PTFE, polyethylene, rubber-based binders, and the like can be used.
  • rubber-based binder components include rubbers typified by aliphatics such as EPT, EPDM, butyl rubber, propylene rubber and natural rubber, or rubbers containing aromatic rubbers such as styrene butadiene rubber. It is done.
  • the structure of these rubbers may contain a hetero-containing substrate such as nitrile, acrylic, force sulfonyl, or silicon, and is not limited to straight chain or branching. In addition, even if these are used individually or in mixture of several, it can become a favorable binder.
  • a conductive material such as carbon black or ketjen black may be added.
  • pure aluminum foil is generally used. Pure aluminum foil or aluminum containing a single metal or a plurality of metals such as copper, manganese, silicon, magnesium, and zinc may be used. Also, stainless steel, nickel cane, titanium, etc. are used similarly. In addition, in order to increase conductivity and secure strength, those added with the above mixture and other elements can also be used. At this time, the surface of these substrates may be roughened by etching or the like, or a conductive metal or carbon may be embedded in the substrate, or may be coated. These current collectors are foil But it can also be used in mesh form.
  • separator in addition to cellulose paper and glass fiber paper, polyethylene terephthalate, polyethylene, polypropylene, polyimide microporous film and a multilayer film composed of these layers are used. Alternatively, PVDF, silicon resin, rubber resin, etc. can be coated on the surface of these separators, or metal oxide particles such as aluminum oxide, silicon dioxide, and magnesium oxide may be embedded. . Of course, these separators may be used by arbitrarily selecting two or more types of separators that do not matter even if there is one or more between the positive and negative electrodes.
  • Organic solvents used as the electrolyte include cyclic carbonates such as propylene carbonate, cyclic esters such as ⁇ -petit-lataton, ⁇ ⁇ heterocyclic compounds such as methylpyrrolidone, nitriles such as acetonitrile, and other sulfolanes and sulfoxides.
  • Polar solvent can be used.
  • solvents can be used alone or in combination of two or more.
  • ammonium salts such as ammonium salt, pyridinium salt, pyrrolidinium salt, piperidinium salt, imidazolium salt, and phosphonium salt are preferred as anions of these salts.
  • Fluorine compounds such as phosphate ion (PF-) and trifluoromethanesulfonate ion are preferred.
  • Jetyldimethylammonium fluoride triethylmethylammonium borofluoride, Hof Butylmethyl ammonium, borofluoride tetrabutyl ammonium, borofluoride tetrahexyl ammonium, borofluoride propyltrimethylammonium, borofluoride butyltrimethylammonium, borofluoride heptyltrimethylammonium, borofluoride (4 pentyl) trimethylammonium, tetradecyltrimethylammonium borofluoride, hexadecyltrimethylammonium borofluoride, heptadecyltrimethylammonium borofluoride, octadecyltrimethylammonium borofluoride, 1,1, -difluoro-2,2-bipyridinium bistetrafluoroborate, borofluoride N, N di
  • electrolytes can be used alone or in combination of two or more.
  • TIMCAL Ltd. Graphite Tim Rex KS6 as a positive electrode active material (002 interlayer distance 0. 3357 ⁇ m, an average particle diameter of 3.4 111, surface area of 20 m 2 / g) Powder electrochemical Co. acetylene Bed rack 8 parts per 84 parts After mixing, a slurry was prepared with an NMP solution of 8 parts of PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode having a thickness of 140 m was prepared on an aluminum foil. As a negative electrode active material, Kuraray Chemical Co., Ltd.
  • activated carbon RP-20, average particle size 2 111, surface area 1800m 2 / g 84 parts of acetylene black is mixed with powder, then PVDF 8 parts NMP solution to prepare slurry, A negative electrode having a thickness of 100 Hm was prepared on an aluminum foil.
  • the weight ratio of positive electrode active material weight / negative electrode active material weight was 1.25 / 1, glass fiber was used for the separator, and 1.5 M / liter TEMABF PC solution was used for the electrolyte, and the electrode area was 3. 14 cm 2
  • Assembling type cell was assembled.
  • the gas generated in this cell is a gap in the Teflon insulation sleeve. Is released.
  • CC charge constant current charge
  • CV charge constant voltage charge
  • the discharge capacity when CC discharge to 0 V at 1 mA was 37.6 mAh / g (based on the weight of the positive electrode active material).
  • CC charging was performed up to 3.5V as an open charge, and CV charging was performed at 3.5V for 10 minutes. After that, 10 cycles of CC discharge to 0V at 1mA were performed.
  • Fig. 19 shows a dQ / dV curve obtained by converting the charge / discharge curve up to 10 cycles at the time of open charge based on the voltage change. From Fig. 19, it can be seen that the capacity increases with each cycle and the transition voltage decreases. 3.
  • the charge voltage was changed to 3.2V and a charge / discharge test was conducted. 3.
  • the discharge capacity after 2V charge was 48.4 mAh / g (based on the weight of the positive electrode active material), and the capacity increased by 28.7% by the open charge treatment of this embodiment.
  • Activated carbon RP-20 (Kuraray Chemical Co., Ltd.) with a mean particle size of 2 m and a surface area of 1800 m 2 / g as a positive and negative electrode active material.
  • a positive electrode having a thickness of 150 am and a negative electrode having a thickness of 100 ⁇ m were prepared on an anoremi foil.
  • the weight ratio of positive electrode active material weight / negative electrode active material weight was adjusted to 1.5 / 1, and an assembly type cell was assembled in the same manner as in Example A-1. CC charge to 2.3V at 1mA and CV charge at 2.3V for 10 minutes.
  • the initial discharge capacity after CC discharge to 1 V at 0 mA was 25.8 mAh / g (based on the weight of the positive electrode active material), and the same as Example A-1 except that the voltage was 2.6 V. 10 Cycle open charge.
  • CC charge to 2.3V was performed again at 1mA, and CV charge was performed at 2.3V for 10 minutes.
  • the discharge capacity after CC discharge to 0V at 1mA was 23. OmAh / g (based on the weight of positive electrode active material), and no increase in capacity due to open charge was observed.
  • Graphite Timrex SFG44 manufactured by TIMCAL as positive electrode active material (002 interlayer distance 0.335 4 nm, average particle diameter 23.8 m, surface area 5 m 2 / g) 8 parts of acetylene black manufactured by Electrochemical Co., Ltd. as powder
  • a slurry was prepared with an NMP solution of 8 parts of PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode having a thickness of 140 m was prepared on an aluminum foil.
  • Kuraray Chemical as negative electrode active material After mixing 8 parts of acetylene black with 84 parts of activated carbon RP-20, average particle size 2 111, surface area 1800m 2 / g, a slurry was prepared with NMP solution of 8 parts of PVDF, and the thickness on the aluminum foil A 100 am negative electrode was prepared.
  • the weight ratio of positive electrode active material weight / negative electrode active material weight is 1.2 / 1, glass fiber is used for the separator, and 1.5 M / liter TEMABF PC solution is used for the electrolyte, and the electrode area is 3. 14 cm 2
  • Assembling type cell was assembled. The gas generated in this cell is released from the gap between the Teflon insulation sleeves. In the 1st and 2nd cycles, CC charge was performed at 1mA to 3.2V, and 3.2V was charged for 10 minutes. After that, CC was discharged to 0V at 1mA. The discharge capacity in the second cycle was 41.6 mAh / g (based on the weight of the positive electrode active material).
  • TIMCAL graphite Timrex SFG44 (002 interlayer distance 0.335 nm, average particle diameter 23.8 m, surface area 5.
  • Om 2 / g) 84 parts by Electrochemical Acetylene Black 8 parts
  • slurry was prepared with NMP solution of 8 parts PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode was prepared on aluminum foil.
  • 8 parts of acetylene black was mixed with 84 parts of activated carbon RP-20, Kuraray Chemical Co., Ltd., average particle size 2 111, surface area 1800 m 2 / g, and then a slurry was prepared with 8 parts of PVDF NMP solution.
  • a negative electrode was prepared on an aluminum foil.
  • the weight ratio of positive electrode active material weight / negative electrode active material weight is 1 / 1.5, glass fiber is used for the separator, 1.5M / Litt Nore PC solution of TEMABF is used for the electrolyte, and the electrode area is 3. 14cm.
  • Two assembled cells were assembled. The generated gas is released from the gap between the Teflon insulation sleeves. First, CC charge (constant current charge) was performed up to 3.5V at 1mA, and CV charge (constant voltage charge) was performed at 3.5V for 30 minutes. Thereafter, 5 cycles of CC discharge to 1 V at 1 mA and CV discharge at 0 V for 30 minutes were performed.
  • Figure 2-9 shows the dQ / dV curve obtained by converting the charge / discharge curve at this time based on the voltage change. From this figure, it can be seen that the transition voltage increases with each site. On the other hand, the discharge capacity at high voltage was almost constant despite the high transition voltage.
  • a positive electrode and a negative electrode were prepared in the same manner as in Example B-1, and an assembly type cell was prepared.
  • TIMCAL graphite Timrex SFG15 (002 interlayer distance 0.33 55 nm, average particle size 8.8 m, surface area 9.5 m 2 / g) is used for the positive electrode graphite
  • the graphite porous body SP440 (002 interlayer distance 0. 3371nm, the average particle diameter of 13. O ⁇ m, surface area 440m 2 / g) was used.
  • the positive electrode / negative electrode weight ratio was 1/2. Using this cell, CC charge was first performed to 3.5V at 1mA, and CV charge was performed at 3.5V for 30 minutes.
  • Figure 2-10 shows the dQ / dV curve obtained by converting the charge / discharge curve at this time based on the voltage change.
  • a positive electrode and a negative electrode were prepared by the method of Example B-1. However, the weight ratio of the positive electrode active material weight / negative electrode active material weight was adjusted to 1/1.
  • An assembly type cell was assembled in the same manner as in Example B-1. CC charge to 3.2V at 1mA and CV charge at 3.2V for 30 minutes. afterwards 5 cycles of CC discharge to OV at 1 mA and CV discharge for 30 minutes at OV. There was no significant change in transition voltage after 5 cycles. The results are shown in Figure 2-11. 3.
  • the discharge capacity in the 10th cycle of 2V charge was 46.5 mAh / g (positive electrode weight basis) in the voltage range of 1.4V to 3.2V.
  • the voltage at the time of discharge extended to a low voltage, which was slightly inferior in terms of energy capacity.
  • a 2032 coin cell was prepared with the same electrode configuration prepared in Example B-1 and Comparative Example B-1, and a cycle test was performed 5000 times at a 10C rate between 2.3V and 3.2V.

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Abstract

Provided is a charging device including an anode containing a carbonic activation substance and a cathode. An electric charging process at the anode indicates an adsorption process of anions in a low-voltage region and an intercalation process in a high-voltage region. The electric charge at the cathode is caused by the adsorption of cations. At the complete discharge time, the state is made such that the cathode is inversely charged with the positive charge, or such that the cathode is charged with the unreleased but left negative charge.

Description

明 細 書  Specification
蓄電デバイスおよびその製造方法  Electric storage device and manufacturing method thereof
技術分野  Technical field
[0001] 本発明は電圧が高ぐ容量が大きぐかつ充放電サイクルにおける信頼性の高い蓄 電デバイス、蓄電システム、およびそれを用いた電子機器、動力システムに関する。 背景技術  TECHNICAL FIELD [0001] The present invention relates to a power storage device, a power storage system, an electronic device using the same, and a power system that have a high voltage, a large capacity, and high reliability in a charge / discharge cycle. Background art
[0002] 非水電解液を使用する蓄電デバイスとして知られているものにはリチウムイオン二 次電池や電気二重層キャパシタなどがある。  [0002] As a power storage device using a non-aqueous electrolyte, there are a lithium ion secondary battery and an electric double layer capacitor.
[0003] リチウムイオン二次電池は正極にリチウム含有遷移金属酸化物が使用され、負極に はリチウムがインター力レート可能な黒鉛系炭素化合物が好適に使用されており、電 解液としてはリチウム塩を含む非水電解液が利用されている。  [0003] In lithium ion secondary batteries, a lithium-containing transition metal oxide is used for the positive electrode, and a graphite-based carbon compound capable of intercalating lithium is preferably used for the negative electrode. A non-aqueous electrolyte containing is used.
[0004] リチウムイオン二次電池では通常、正極にリチウム含有遷移金属酸化物を使用して いるために、リチウムイオン二次電池は高い電圧による充放電を実現でき、結果とし て高容量な電池と認識される一方で、正負極活物質自体にリチウムイオンを吸蔵 '脱 離するために充放電サイクルの劣化が早期に起こってしまう。  [0004] Since lithium-ion secondary batteries usually use a lithium-containing transition metal oxide for the positive electrode, the lithium-ion secondary battery can realize charging and discharging at a high voltage, resulting in a high-capacity battery. On the other hand, the positive and negative electrode active materials themselves occlude and desorb lithium ions, resulting in early deterioration of the charge / discharge cycle.
[0005] 一方、電気二重層キャパシタは、正極、負極共に活性炭を主体とする分極性電極 にて構成されているために容量は低いながらも、急速な充放電を可能にし、かつ充 放電サイクルにおける高レ、信頼性を確保出来てレ、る。  [0005] On the other hand, since the electric double layer capacitor is composed of a polarizable electrode mainly composed of activated carbon for both the positive electrode and the negative electrode, it enables rapid charge and discharge even though the capacity is low, and in the charge and discharge cycle. High level and reliability can be secured.
[0006] しかしながら、分極性電極と電解液の界面に形成される電気二重層を利用すること で安定した電源を構成する電気二重層キャパシタの電気エネルギーは 1/2CV2で 表されることから、より高!/、電圧で作動させる電気化学系が求められてレ、る。 [0006] However, since the electric energy of the electric double layer capacitor that constitutes a stable power supply by using the electric double layer formed at the interface between the polarizable electrode and the electrolyte is expressed by 1/2 CV 2 , There is a need for an electrochemical system that operates at a higher voltage!
[0007] 電気二重層キャパシタの蓄電システムにおける容量向上の為に近年研究されたシ ステムとしては、正極に PFPT (ポリ一 p—フルオロフェニルチオフェン）を使用し、負 極に活性炭を使用するものが提案されている。また、正極に活性炭を使用し、負極に チタン酸リチウムを使用するもの、あるいは、正極に活性炭を使用し、負極が黒鉛系 炭素というものが提案されている。し力、しながら、これら提案の蓄電システムにおいて は、充放電サイクル初期の劣化、急速充放電による容量低下、黒鉛系炭素へのリチ ゥムイオンの揷入脱離の繰り返しによる構造の劣化の可能性が報告されて!/、る。例え ば、特許文献 1には、電気二重層キャパシタの電極材料となる特殊な炭素材、及び その製造方法にっレ、て提案されてレ、る。 [0007] As a system recently studied for improving the capacity of an electric double layer capacitor storage system, one using PFPT (poly (p-fluorophenylthiophene)) for the positive electrode and activated carbon for the negative electrode is used. Proposed. Also proposed are those using activated carbon for the positive electrode and lithium titanate for the negative electrode, or using activated carbon for the positive electrode and graphite-based carbon for the negative electrode. However, in these proposed energy storage systems, deterioration at the initial stage of charge / discharge cycles, capacity reduction due to rapid charge / discharge, The possibility of structural degradation due to repeated insertion and desorption of um ions has been reported! For example, Patent Document 1 proposes a special carbon material used as an electrode material for an electric double layer capacitor and a method for manufacturing the same.
[0008] 特許文献 2には、（002)ピークの X線回折での半値幅が 0. 5〜5. 0。 である黒鉛 系炭素材料を正極及び負極の両電極の主成分として含む電気二重層キャパシタに ついて提案されているが、実施例に示されているように、電気二重層キャパシタを作 製した後に水蒸気賦活処理の代わりに、 20分〜 5時間、 3. 8Vの高電圧を印加して 使用することを特 ί毁としてレ、る。  [0008] In Patent Document 2, the half-value width in the X-ray diffraction of the (002) peak is 0.5 to 5.0. An electric double layer capacitor containing the graphite-based carbon material as the main component of both the positive electrode and the negative electrode has been proposed, but as shown in the examples, after the electric double layer capacitor was fabricated, Instead of activation treatment, use a high voltage of 3.8V for 20 minutes to 5 hours.
[0009] さらに、特許文献 3には、正極の炭素材料として、ホウ素またはホウ素化合物を含有 する炭素材料を熱処理して得られるホウ素含有黒鉛を使用し、負極の炭素材料とし て活性炭を使用した電気二重層キャパシタが提案されている。特許文献 3では、正 極おけるァニオンのインターカレーシヨン反応を推定している力 S、充放電過程の詳細 は明らかにされていない。またホウ素含有黒鉛の比表面積等の物理的性質に関する 詳細も明らかにされて!/、なレ、。  [0009] Furthermore, Patent Document 3 uses an electric power in which boron-containing graphite obtained by heat treatment of a carbon material containing boron or a boron compound is used as the positive electrode carbon material, and activated carbon is used as the negative electrode carbon material. Double layer capacitors have been proposed. Patent Document 3 does not disclose details of the force S for estimating the anion intercalation reaction at the positive electrode and the charge / discharge process. Details regarding physical properties such as specific surface area of boron-containing graphite have also been clarified!
[0010] さらに特許文献 4にも、正極活物質として黒鉛を使用し、負極の活物質として黒鉛ま たは活性炭を使用する電気二重層キャパシタが提案されて!/、る力 キャパシタ容量 が正極および負極でのイオンの吸脱着によって発現するとされている。  [0010] Further, Patent Document 4 also proposes an electric double layer capacitor using graphite as a positive electrode active material and using graphite or activated carbon as a negative electrode active material! It is said that it is expressed by the adsorption and desorption of ions at the negative electrode.
[0011] 特許文献 1 :特開平 10— 199767号公報  Patent Document 1: Japanese Patent Laid-Open No. 10-199767
特許文献 2：特開 2002— 151364号公報  Patent Document 2: JP 2002-151364 A
特許文献 3：特開 2004 _ 134658号公報  Patent Document 3: Japanese Unexamined Patent Application Publication No. 2004_134658
特許文献 4：特開 2005— 294780号公報  Patent Document 4: Japanese Patent Laid-Open No. 2005-294780
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0012] 以上のように、従来正極として黒鉛や活性炭を使用した非水系の電気二重層キヤ パシタの提案はあったが、実際に使用できる蓄電容量およびエネルギー容量が十分 ではなぐまた充放電過程の適正な制御がされていないためにサイクル特性が不十 分であった。 [0012] As described above, there has been a proposal of a non-aqueous electric double layer capacitor using graphite or activated carbon as a positive electrode in the past. However, the storage capacity and energy capacity that can be actually used are not sufficient, and the charge / discharge process is not possible. The cycle characteristics were insufficient due to improper control.
[0013] 本発明は従来の鉛電池、リチウムイオン二次電池、ニッケル水素二次電池、電気二 重層キャパシタ等を代替することが可能で、実質的に利用できる蓄電容量およびェ ネルギー容量が大きぐかつ充放電サイクルにおける信頼性が高い、蓄電デバイスを 提供することを目的とする。 [0013] The present invention relates to a conventional lead battery, lithium ion secondary battery, nickel metal hydride secondary battery, electric An object of the present invention is to provide an electricity storage device that can replace a multilayer capacitor and the like, has a substantially large storage capacity and energy capacity, and has high reliability in a charge / discharge cycle.
課題を解決するための手段  Means for solving the problem
[0014] 本発明は、完全放電時に負極が正電荷で逆充電された状態になる第 1の態様（以 下、態様 A)と、完全放電時に負極が放電されずに残存する負電荷で充電された状 態になる第 2の態様 (以下、態様 B)の 2つの態様を含む。 [0014] The present invention relates to a first mode in which the negative electrode is reversely charged with a positive charge during complete discharge (hereinafter referred to as mode A), and charging with a negative charge remaining without discharging the negative electrode during complete discharge. It includes two embodiments of the second embodiment (hereinafter referred to as embodiment B).
[0015] 本発明の態様 Aは、以下の事項により特徴づけられる。 [0015] Aspect A of the present invention is characterized by the following matters.
[0016] 1. 炭素質活物質を含有する正極および負極を備える蓄電デバイスであって、 正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と高電 圧領域におけるインターカレーシヨン過程を示し、  [0016] 1. An electricity storage device including a positive electrode and a negative electrode containing a carbonaceous active material, wherein the electrical charging process at the positive electrode comprises the adsorption process of ayuon in the low voltage region and the intercalation process in the high voltage region. Show
負極における電気的充電力 S、カチオンの吸着により生じ、  Electric charge S at the negative electrode S, generated by adsorption of cations,
完全放電時に、前記負極が正電荷で逆充電された状態になることを特徴とする蓄 電デバイス。  A storage device, wherein the negative electrode is reversely charged with a positive charge when fully discharged.
[0017] 2. 前記正極および負極は、初期充電時に正極が最大許容電気量に達する前に 、負極電位が負極での不可逆反応電位を超えるように設定され、  [0017] 2. The positive electrode and the negative electrode are set so that the negative electrode potential exceeds the irreversible reaction potential at the negative electrode before the positive electrode reaches the maximum allowable amount of electricity during initial charging,
負極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放電を行 つて製造されたことを特徴とする上記 1記載の蓄電デバイス。  2. The electricity storage device according to 1 above, which is produced by performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the negative electrode.
[0018] 3. サイクリックボルタンメトリー法で充放電曲線を描いた時、正極でのァニオンの インターカレーシヨンが開始された直後に、 dQ/dV値が極大値に達した後、充電電 圧の上昇に伴い dQ/dV値が漸減し、 dQ/dV値が極小値に達した後、再び漸増 する dQ/dV曲線を有することを特徴とする上記 1または 2記載の蓄電デバイス。  [0018] 3. When the charge / discharge curve is drawn by cyclic voltammetry, the charge voltage rises after the dQ / dV value reaches the maximum immediately after the start of the canyon intercalation at the positive electrode. 3. The electrical storage device according to 1 or 2 above, further comprising a dQ / dV curve that gradually decreases after the dQ / dV value gradually decreases and reaches a minimum value.
[0019] 4. 正極へのァニオンのインターカレーシヨンが開始する遷移電圧力 S、 0. 5Vから 1. 75Vの範囲であることを特徴とする上記 1〜3のいずれかに記載の蓄電デバイス。  [0019] 4. The electric storage device according to any one of the above items 1 to 3, wherein the transition voltage force S at which the intercalation of the anion to the positive electrode starts is in the range of 0.5V to 1.75V.
[0020] 5. 前記負極の動作電圧範囲が、この負極が本来有するカチオン吸着に基づく動 作電圧範囲の 10%以上拡大されていることを特徴とする上記 1〜3のいずれかに記 載の蓄電デバイス。  [0020] 5. The operating voltage range of the negative electrode is expanded by 10% or more of the operating voltage range based on cation adsorption inherent in the negative electrode, as described in any one of 1 to 3 above Power storage device.
[0021] 6. 前記負極の充電可能な積算容量が、この負極が本来有するカチオン吸着に 基づく充電可能な積算容量の 10〜60%の範囲で拡大されていることを特徴とする 上記 1〜3のいずれかに記載の蓄電デバイス。 [0021] 6. The cumulative chargeable capacity of the negative electrode contributes to the cation adsorption inherent in the negative electrode. 4. The electricity storage device according to any one of 1 to 3 above, which is expanded in a range of 10 to 60% of an accumulated chargeable capacity.
[0022] 7. 前記開放充電時に、電解液の溶媒の耐電圧より高い電圧まで印加されたこと を特徴とする上記 2の蓄電デバイス。 [0022] 7. The electric storage device according to 2 above, wherein a voltage higher than a withstand voltage of a solvent of the electrolytic solution is applied during the open charging.
[0023] 8. 前記正極の活物質として黒鉛質材料が使用され、 [0023] 8. A graphite material is used as an active material of the positive electrode,
前記負極の活物質として正極の活物質として使用される黒鉛質材料より比表面積 の大きい炭素質材料が使用されることを特徴とする上記 1〜7のいずれかに記載の蓄 電デバイス。  8. The electricity storage device according to any one of 1 to 7 above, wherein a carbonaceous material having a specific surface area larger than that of a graphite material used as a positive electrode active material is used as the negative electrode active material.
[0024] 9. 前記負極で使用される炭素質材料が活性炭であることを特徴とする上記 8記 載の蓄電デバイス。  [0024] 9. The electricity storage device as described in 8 above, wherein the carbonaceous material used in the negative electrode is activated carbon.
[0025] 10. 蓄電デバイスとしての使用時において、充電時の正極電位が 5. 2Vvs. Li+ [0025] 10. When used as an electricity storage device, the positive electrode potential during charging is 5.2 Vvs. Li +
/Liを超えない範囲で使用されることを特徴とする上記 1〜9のいずれかに記載の蓄 電デバイス。 The power storage device according to any one of 1 to 9 above, which is used in a range not exceeding / Li.
[0026] 11. 蓄電デバイスとしての使用時において、充電電圧 3. 2V以下の範囲で使用さ れることを特徴とする上記;!〜 9のいずれかに記載の蓄電デバイス。  [0026] 11. The electricity storage device according to any one of the above;! To 9, wherein the electricity storage device is used in a range of a charging voltage of 3.2 V or less when used as an electricity storage device.
[0027] 12. 炭素質活物質を含有する正極および負極を備える蓄電デバイスの製造方法 であって、  [0027] 12. A method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
(a)正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と 高電圧領域におけるインターカレーシヨン過程を示し、（b)負極における電気的充電 1S カチオンの吸着により生じ、（c)初期充電時に正極が最大許容電気量に達する 前に、負極電位が負極での不可逆反応電位を超えるように、正極および負極材料の 容量を設定し、  (a) The electrical charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region, (b) the electrical charging at the negative electrode occurs due to the adsorption of 1S cations, (c) the initial stage Set the capacities of the positive and negative electrode materials so that the negative electrode potential exceeds the irreversible reaction potential at the negative electrode before the positive electrode reaches the maximum allowable amount of electricity during charging.
前記負極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放 電を行うことを特徴とする蓄電デバイスの製造方法。  A method for producing an electricity storage device, comprising performing at least one open charge and open charge at a voltage at which an irreversible reaction occurs at the negative electrode.
[0028] 13. 前記開放充電時に、負極が有する電荷量に加えて、負極で起きる不可逆反 応で消費した電子に相当する電気量を、正極に正の電荷として蓄電し、 [0028] 13. At the time of the open charge, in addition to the charge amount of the negative electrode, the amount of electricity corresponding to the electrons consumed by the irreversible reaction that occurs in the negative electrode is stored as positive charge in the positive electrode,
前記開放放電時に、前記正極と負極の電位がバランスするように完全放電し、その 際に、前記不可逆反応を利用して充電した正極の電荷を放出して負極を正電荷で 逆充電することを特徴とする上記 12記載の製造方法。 At the time of the open discharge, a complete discharge is performed so that the potentials of the positive electrode and the negative electrode are balanced. At that time, the charge of the positive electrode charged using the irreversible reaction is discharged, and the negative electrode is positively charged. 13. The production method according to 12 above, wherein reverse charging is performed.
[0029] 14. 前記負極での不可逆反応が、電解液の溶媒の還元分解であることを特徴と する上記 12または 13記載の製造方法。 [0029] 14. The production method according to the above 12 or 13, wherein the irreversible reaction at the negative electrode is reductive decomposition of a solvent of an electrolytic solution.
[0030] さらに、本発明の態様 Bは、以下の事項により特徴づけられる。 [0030] Further, aspect B of the present invention is characterized by the following matters.
[0031] 1. 炭素質活物質を含有する正極および負極を備える蓄電デバイスであって、 正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と高電 圧領域におけるインターカレーシヨン過程を示し、 [0031] 1. An electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material, wherein the electrical charging process at the positive electrode comprises an adsorption process of ayuons in a low voltage region and an intercalation process in a high voltage region. Show
負極における電気的充電力 S、カチオンの吸着により生じ、  Electric charge S at the negative electrode S, generated by adsorption of cations,
完全放電時に、前記負極が、放電されずに残存する負電荷で充電されていること を特徴とする蓄電デバイス。  An electricity storage device, wherein the negative electrode is charged with a negative charge remaining without being discharged at the time of complete discharge.
[0032] 2. 前記正極および負極は、初期充電時に負極が最大許容電気量に達する前に[0032] 2. The positive electrode and the negative electrode must be connected before the negative electrode reaches the maximum allowable amount of electricity during initial charging.
、正極電位が正極での不可逆反応電位を超えるように設定され、 The positive electrode potential is set to exceed the irreversible reaction potential at the positive electrode,
正極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放電を行 つて製造されたことを特徴とする上記 1記載の蓄電デバイス。  2. The electricity storage device according to 1 above, which is produced by performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
[0033] 3. 正極へのァニオンのインターカレーシヨンが開始する遷移電圧が、 1. 75V力、 ら 2. 5Vの範囲であることを特徴とする上記 1または 2記載の蓄電デバイス。 [0033] 3. The electricity storage device according to 1 or 2 above, wherein the transition voltage at which the intercalation of the anion to the positive electrode starts is in the range of 1.75V force, and 2.5V.
[0034] 4. 正極の充電可能な積算容量が、負極の充電可能な積算容量の 95%以下であ ることを特徴とする上記 1〜3のいずれかに記載の蓄電デバイス。 [0034] 4. The electricity storage device according to any one of 1 to 3 above, wherein an accumulated capacity that can be charged to the positive electrode is 95% or less of an accumulated capacity that can be charged to the negative electrode.
[0035] 5. 前記開放充電時の不可逆反応電荷量が、負極が本来有するカチオン吸着に 基づく電荷量の 10〜60%であることを特徴とする上記 2の蓄電デバイス。 [0035] 5. The electric storage device according to 2 above, wherein the irreversible reaction charge amount during open charge is 10 to 60% of the charge amount based on cation adsorption inherent in the negative electrode.
[0036] 6. 前記不可逆反応が、電解液の溶媒の分解反応であることを特徴とする上記 2 記載の蓄電デバイス。 [0036] 6. The electricity storage device as described in 2 above, wherein the irreversible reaction is a decomposition reaction of a solvent of the electrolytic solution.
[0037] 7. 開放充電時に、電解液の耐電圧より高い電圧まで印加されたことを特徴とする 上記 6記載の蓄電デバイス。  [0037] 7. The electric storage device according to 6 above, wherein a voltage higher than a withstand voltage of the electrolytic solution is applied during open charge.
[0038] 8. 前記不可逆反応が、添加された材料の反応を伴うことを特徴とする上記 2記載 の蓄電デバイス。 [0038] 8. The electricity storage device according to 2 above, wherein the irreversible reaction is accompanied by a reaction of an added material.
[0039] 9. 前記正極の活物質として黒鉛質材料が使用され、 [0039] 9. A graphite material is used as an active material of the positive electrode,
前記負極の活物質として正極の活物質として使用される黒鉛質材料より比表面積 の大きい炭素質材料が使用されることを特徴とする上記 1〜8のいずれかに記載の蓄 電デバイス。 Specific surface area from the graphite material used as the active material of the positive electrode as the active material of the negative electrode A power storage device according to any one of 1 to 8 above, wherein a carbonaceous material having a large size is used.
[0040] 10. 前記負極で使用される炭素質材料が活性炭であることを特徴とする上記 9記 載の蓄電デバイス。  [0040] 10. The electricity storage device as described in 9 above, wherein the carbonaceous material used in the negative electrode is activated carbon.
[0041] 11. 蓄電デバイスとしての使用時において、充電時の正極電位が 5. 2Vvs. Li+ [0041] 11. When used as an electricity storage device, the positive electrode potential during charging is 5.2 Vvs. Li +
/Liを超えない範囲で使用されることを特徴とする上記 1〜； 10のいずれかに記載の 蓄電デバイス。 11. The electricity storage device according to any one of 1 to 10 above, which is used in a range not exceeding / Li.
[0042] 12. 蓄電デバイスとしての使用時において、充電電圧 3. 5V未満の範囲で使用さ れることを特徴とする上記;!〜 10のいずれかに記載の蓄電デバイス。  [0042] 12. The electricity storage device according to any one of the above;! To 10, wherein the electricity storage device is used in a range of a charging voltage of less than 3.5 V when used as an electricity storage device.
[0043] 13. 炭素質活物質を含有する正極および負極を備える蓄電デバイスの製造方法 であって、  [0043] 13. A method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
(a)正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と 高電圧領域におけるインターカレーシヨン過程を示し、（b)負極における電気的充電 1S カチオンの吸着により生じ、（c)初期充電時に負極が最大許容電気量に達する 前に、正極電位が正極での不可逆反応電位を超えるように、正極および負極材料の 容量を設定し、  (a) The electrical charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region, (b) the electrical charging at the negative electrode occurs due to the adsorption of 1S cations, (c) the initial stage Set the capacities of the positive and negative electrode materials so that the positive electrode potential exceeds the irreversible reaction potential at the positive electrode before the negative electrode reaches the maximum allowable amount of electricity during charging.
前記正極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放 電を行うことを特徴とする蓄電デバイスの製造方法。  A method for manufacturing an electricity storage device, comprising performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
[0044] 14. 前記開放充電時に、正極が有する電荷量に加えて、正極で起きる不可逆反 応で消費した正孔に相当する電気量を、負極に負の電荷として蓄電し、 [0044] 14. During the open charge, in addition to the charge amount of the positive electrode, an amount of electricity corresponding to holes consumed by the irreversible reaction occurring in the positive electrode is stored as a negative charge in the negative electrode,
前記開放放電時に、前記正極と負極の電位がバランスするように完全放電し、その 際に、前記不可逆反応を利用して蓄電した負極の電荷が、負極に残存することを特 徴とする上記 13記載の製造方法。  In the open discharge, complete discharge is performed so that the potentials of the positive electrode and the negative electrode are balanced, and at this time, the charge of the negative electrode stored by using the irreversible reaction remains in the negative electrode. The manufacturing method as described.
[0045] 15. 前記正極での不可逆反応が、電解液の溶媒の酸化分解であることを特徴と する上記 13または 14記載の製造方法。 [0045] 15. The production method according to the above 13 or 14, wherein the irreversible reaction at the positive electrode is oxidative decomposition of a solvent of the electrolytic solution.
発明の効果  The invention's effect
[0046] 本発明によれば、非水系の電気二重層キャパシタに特徴的な高速充放電という性 質を保持したまま、従来の電気二重層キャパシタに比べて高電圧で利用可能で、実 質的に利用できる蓄電容量およびエネルギー容量が大きぐ充放電サイクルにおけ る信頼性が高い蓄電デバイスを提供することができる。 [0046] According to the present invention, while maintaining the characteristic of high-speed charge / discharge characteristic of a non-aqueous electric double layer capacitor, it can be used at a higher voltage than a conventional electric double layer capacitor. It is possible to provide an electricity storage device with high reliability in a charge / discharge cycle in which the electricity storage capacity and energy capacity that can be used qualitatively are large.
[0047] 本発明の蓄電デバイスでは、充放電過程が正極活物質へのァユオンの可逆的吸 着と可逆的インターカレーシヨンの 2段階過程を示すために、デバイス使用時に電解 液の分解反応を抑制しつつ、インターカレーシヨン領域を使用して高容量、特に高工 ネルギー容量の蓄電デバイスを実現できる。本発明の蓄電デバイスは、分極性電極 に電解質が吸着して容量が発現する電気二重層キャパシタの範疇には入らないが、 従来の電池に比べて急速な充放電が可能である。 [0047] In the electricity storage device of the present invention, the charging / discharging process is a two-stage process of reversible adsorption and reversible intercalation of the cation on the positive electrode active material, so that the decomposition reaction of the electrolytic solution is suppressed during device use. However, it is possible to realize a high-capacity storage device, particularly a high-energy storage device, using the intercalation region. The electricity storage device of the present invention does not fall within the category of an electric double layer capacitor in which the electrolyte is adsorbed on the polarizable electrode and develops capacity, but can be charged / discharged more rapidly than a conventional battery.
[0048] <態様 Aに特有の効果〉  [0048] <Effects specific to Aspect A>
本発明の態様 Aでは、完全放電時に、負極が正電荷で逆充電された状態になる。 これは、負極が本来有する吸着能力により発現する電気容量に加えて、逆充電され た正電荷に対応する電気容量を、蓄電し、放電できることを意味する。このため、本 態様によれば、高容量の蓄電デバイスを提供することができる。  In the aspect A of the present invention, the negative electrode is reversely charged with a positive charge during complete discharge. This means that in addition to the electric capacity expressed by the adsorption capability inherent in the negative electrode, an electric capacity corresponding to the positively charged positive charge can be stored and discharged. For this reason, according to this aspect, a high capacity | capacitance electrical storage device can be provided.
[0049] 負極容量を上げるためには表面積の大きな活性炭を用いることも一つの方法では ある力 表面積と電極密度は相反する関係にあるので、体積当たりの容量を重要視 する蓄電デバイスにおレ、てはこの方法は最良の方法とは言!、がたレ、。組上げたデバ イスの中で電気化学的な操作を行い低表面積の活性炭をキャパシタ用活性炭に改 質する方法はナノゲートキャパシタとして公知（特開 2002— 025867等）である。ナノ ゲートキャパシタにおける活性炭の改質は充電時にコータスの炭素層間にイオンをィ ンターカレーシヨンさせることにより、炭素層間を拡大させ、拡大した炭素層間をィォ ン吸着サイトとして利用するものである。し力、しながら本態様 Aの負極活性炭の容量 増加は活性炭に電気化学的処理を加えて表面積の増加などの改質を行うものでは なぐ純粋に充電時の条件のみで本来活性炭が有するイオンの吸着能力をカチオン のみならず、ァニオンにまで拡大するという活性炭のイオン吸着容量、言い換えれば イオンの吸着利用率を高めたものである。  [0049] In order to increase the negative electrode capacity, activated carbon having a large surface area is also used in one method. Since the surface area and the electrode density are in a contradictory relationship, the power storage device that emphasizes the capacity per volume is important. This is probably the best way! A method for modifying a low surface area activated carbon to an activated carbon for a capacitor by performing an electrochemical operation in the assembled device is known as a nanogate capacitor (JP 2002-0225867, etc.). The modification of the activated carbon in the nanogate capacitor is to expand the carbon layer by intercalating ions between the coater carbon layers during charging, and use the expanded carbon layer as an ion adsorption site. However, the increase in the capacity of the negative active carbon of this embodiment A does not involve the modification of the surface area by adding an electrochemical treatment to the activated carbon. It increases the ion adsorption capacity of activated carbon, which expands the adsorption capacity not only to cations but also to anions, in other words, the adsorption utilization rate of ions.
[0050] 後述するように、活性炭としては入手可能な市販の活性炭であってもよぐ正極と負 極の容量バランスを調節し、従来は単にデバイスの安定化処理として行われて!/、た 開放充電の条件を制御することによって、従来の負極活物質としての活性炭の容量 を 2割から 5割引き上げることができる。 [0050] As described later, the activated carbon may be a commercially available activated carbon, and the capacity balance between the positive electrode and the negative electrode may be adjusted. Conventionally, the activated carbon is simply performed as a device stabilization process! /, Capacity of activated carbon as a conventional negative electrode active material by controlling the conditions of open charge Can be raised from 20% to 50%.
[0051] <態様 Bに特有の効果〉  [0051] <Effects specific to Aspect B>
本発明の態様 Bでは、完全放電時に、負極が、放電されずに残存する負電荷で充 電された状態になっているので、等電点が低電位側にシフトし、その結果、正極にお Vヽてァ二オンの吸着からインターカレーシヨンに変化する遷移電圧が上がる。従って 、本態様 Bの蓄電デバイスは、動作電圧が高ぐかつ引き上げられた高電圧域での 容量が確保される。さらに実用に供しない低電圧域での正極に対するァニオンのィ ンターカレーシヨン負荷を減らすことができる。さらに、遷移電圧の上昇は、負極電位 の低下によってもたらされているので、使用時の動作電圧を高くしても、電解液の酸 化反応電位以下でデバイスを使用できる。このようなこと力、ら、本態様 Bの蓄電デバィ スは、高電圧と高容量かつ良好なサイクル特性を有する。  In aspect B of the present invention, at the time of complete discharge, the negative electrode is in a state of being charged with a negative charge remaining without being discharged, so the isoelectric point is shifted to the low potential side, and as a result, the positive electrode is The transition voltage that changes from V-ion adsorption to intercalation increases. Therefore, the power storage device of the present aspect B has a high operating voltage and a capacity in a high voltage range that is pulled up. Furthermore, it is possible to reduce the load of anion intercalation on the positive electrode in the low voltage range that is not practically used. Furthermore, since the increase in the transition voltage is caused by the decrease in the negative electrode potential, the device can be used at a potential lower than the oxidation reaction potential of the electrolytic solution even if the operating voltage during use is increased. For this reason, the electricity storage device of the present embodiment B has high voltage, high capacity, and good cycle characteristics.
[0052] さらに、本態様 Bの蓄電デバイスでは 1. 75V力、ら 3. 5Vと高い動作電圧を得ること が出来ることから、高電圧で急速な充放電を行う分野において本態様 Bの蓄電デバ イスの特徴は有効であり、例えば、エンジンのスターター電源や、 HEV用蓄電デバィ スとして利用できる。例えば HEV用の蓄電デバイスに 200V以上の電圧が必要とさ れる力 従来の電気二重層キャパシタと比較すると、直列するデバイスの個数は 40 %低減される。これは昇圧回路が単純化できるという効果のみならず、直列ゆえに 1 ケのデバイスが故障すると直列部分の全てのエネルギーが得られなくなることから故 障頻度の低減等のメリットが大きい。  [0052] Further, since the power storage device of the present embodiment B can obtain a high operating voltage of 1.75V power, 3.5V, etc., the power storage device of the present embodiment B can be used in a field where rapid charge and discharge is performed at a high voltage. The chair features are effective, and can be used, for example, as an engine starter power supply or a HEV storage device. For example, the power required for a storage device for HEV that requires a voltage of 200V or higher Compared to conventional electric double layer capacitors, the number of devices in series is reduced by 40%. This not only has the effect of simplifying the booster circuit, but also has the merit of reducing the failure frequency because all energy in the series part cannot be obtained if one device fails because of the series.
図面の簡単な説明  Brief Description of Drawings
[0053] [図 1-1]充電前の蓄電デバイスを示す図である。 （A)は正負極の容量と電位、電圧の 関係を示すための模式図であり、横軸は電位、縦軸は静電容量 (dQ/dV)を表す。  [0053] FIG. 1-1 is a diagram showing an electricity storage device before charging. (A) is a schematic diagram for showing the relationship between positive and negative electrode capacities, potentials, and voltages, where the horizontal axis represents the potential and the vertical axis represents the capacitance (dQ / dV).
(B)は正極および負極での電荷バランスを示すための電池の構成の模式図である。  (B) is a schematic diagram of a battery configuration for showing a charge balance between a positive electrode and a negative electrode.
[図 1-2]—部充電状態の蓄電デバイスを示す図である。 (A)と (B)の説明は図 1 1 の説明を参照のこと。  [FIG. 1-2] A diagram showing an electricity storage device in a state of being charged. Refer to the explanation in Fig. 11 for the explanation of (A) and (B).
[図 1-3]負極が充電可能な積算容量に達した状態の蓄電デバイスを示す図である。 ( A)と (B)の説明は図 1 1の説明を参照のこと。  [FIG. 1-3] A diagram showing an electricity storage device in a state where the negative electrode has reached a chargeable integrated capacity. For the explanation of (A) and (B), see the explanation of Fig. 11.
[図 1-4]過充電により不可逆反応が起きている状態の蓄電デバイスを示す図である。 (A)と (B)の説明は図 1 1の説明を参照のこと。 FIG. 1-4 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs due to overcharge. For the explanation of (A) and (B), see the explanation of Fig. 11.
園 1-5]初期の等電点まで放電した状態の蓄電デバイスを示す図である。 (A)と（B) の説明は図 1 1の説明を参照のこと。 1-5] It is a diagram showing an electricity storage device in a state of being discharged to an initial isoelectric point. Refer to the explanation of Fig. 11 for the explanation of (A) and (B).
園 1-6]完全放電した状態の蓄電デバイスを示す図である。 (A)と (B)の説明は図 1 1の説明を参照のこと。 1-6] is a diagram showing the electricity storage device in a fully discharged state. For the explanation of (A) and (B), see the explanation of Fig. 11.
[図 1_7]2回目の過充電により不可逆反応が起きて!/、る状態の蓄電デバイスを示す図 である。 (A)と（B)の説明は図 1— 1の説明を参照のこと。  [FIG. 1_7] A diagram showing an electricity storage device in a state where an irreversible reaction occurs due to the second overcharge! See the description of Figure 1-1 for an explanation of (A) and (B).
[図 1-8]2回目の過充電後に完全放電した状態の蓄電デバイスを示す図である。 (A) と（B)の説明は図 1 1の説明を参照のこと。  FIG. 1-8 is a diagram showing an electricity storage device that has been completely discharged after the second overcharge. See the description of Figure 11 for an explanation of (A) and (B).
園 1-9]実施例 A—1で 10回まで過充電電圧まで開放充放電を繰り返したときの蓄電 デバイスの特性を示すグラフである。 [Sen-1-9] This is a graph showing the characteristics of an electricity storage device when open charge / discharge is repeated up to overcharge voltage up to 10 times in Example A-1.
園 1-10]実施例 A— 1で 1回目と 10回目の充電時の蓄電デバイスの特性を示すダラ フでめる。 (Sen 1-10) Example A—Draw a graph indicating the characteristics of the electricity storage device during the first and tenth charging in Example 1.
[図 1-11]実際のデバイスにおいて、静電容量の電圧依存性を模式的に示すグラフで ある。  [Fig. 1-11] This is a graph schematically showing the voltage dependence of capacitance in an actual device.
園 1-12]実際のデバイスにおける静電容量の電圧依存性を考慮して、負極の静電容 量（dQ/dV)を書き換えた図である。 (Sono 1-12) This figure is a rewrite of the negative electrode capacitance (dQ / dV) in consideration of the voltage dependence of capacitance in actual devices.
[図 1-13]実施例 A— 2で過充電電圧まで開放充放電を繰り返したときの蓄電デバィ 園 1-15]使用時の蓄電デバイスの限界充電電位と端子間電圧を説明するための図 である。 (A)と（B)の説明は図 1— 1の説明を参照のこと。  [Fig. 1-13] Storage device when open charge / discharge is repeated to overcharge voltage in Example A-2 1-15] Diagram for explaining the limit charge potential and inter-terminal voltage of the storage device when in use It is. See the description of Figure 1-1 for an explanation of (A) and (B).
[図 2-1]充電前の蓄電デバイスを示す図である。 （A)は正負極の容量と電位、電圧の 関係を示すための模式図であり、横軸は電位、縦軸は静電容量 (dQ/dV)を表す。 FIG. 2-1 is a diagram showing an electricity storage device before charging. (A) is a schematic diagram for showing the relationship between positive and negative electrode capacities, potentials, and voltages, where the horizontal axis represents the potential and the vertical axis represents the capacitance (dQ / dV).
(B)は正極および負極での電荷バランスを示すための電池の構成の模式図である。 園 2-2]—部充電状態の蓄電デバイスを示す図である。 （A)と (B)の説明は図 2—1 の説明を参照のこと。 (B) is a schematic diagram of a battery configuration for showing a charge balance between a positive electrode and a negative electrode. Fig. 2-2 is a diagram showing the electricity storage device in a state of being charged. For the explanation of (A) and (B), see the explanation of Figure 2-1.
園 2-3]正極が充電可能な積算容量に達した状態の蓄電デバイスを示す図である。 ( A)と（B)の説明は図 2 1の説明を参照のこと。 [図 2-4]過充電により、正極で不可逆反応が起きている状態の蓄電デバイスを示す図 である。 (A)と（B)の説明は図 2 1の説明を参照のこと。 FIG. 2-3] is a diagram showing the electricity storage device in a state where the accumulated capacity that can be charged by the positive electrode has been reached. See the description of Figure 21 for an explanation of (A) and (B). FIG. 2-4 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs at the positive electrode due to overcharge. For the explanation of (A) and (B), see the explanation of Fig. 21.
園 2-5]初期の等電点まで放電した状態の蓄電デバイスを示す図である。 (A)と（B) の説明は図 2 1の説明を参照のこと。 2-5] is a diagram showing the electricity storage device in a state where it has been discharged to the initial isoelectric point. Refer to the explanation of Fig. 21 for explanation of (A) and (B).
[図 2-6]完全放電した状態の蓄電デバイスを示す図である。 （A)と（B)の説明は図 2 1の説明を参照のこと。  FIG. 2-6 is a diagram showing an electricity storage device in a completely discharged state. See the description of Figure 21 for an explanation of (A) and (B).
[図 2-7]2回目の過充電により不可逆反応が起きて!/、る状態の蓄電デバイスを示す図 である。 (A)と（B)の説明は図 2 1の説明を参照のこと。  FIG. 2-7 is a diagram showing an electricity storage device in a state where an irreversible reaction occurs due to the second overcharge! For the explanation of (A) and (B), see the explanation of Fig. 21.
[図 2-8]2回目の過充電後に完全放電した状態の蓄電デバイスを示す図である。 (A) と（B)の説明は図 2 1の説明を参照のこと。  FIG. 2-8 is a diagram showing an electricity storage device that has been completely discharged after the second overcharge. For the explanation of (A) and (B), see the explanation of Fig. 21.
園 2-9]実施例 B— 1で 5回まで過充電電圧まで開放充放電を繰り返したときの蓄電 デバイスの特性を示すグラフである。 Fig. 2-9] This is a graph showing the characteristics of the electricity storage device when open charge / discharge is repeated up to the overcharge voltage up to 5 times in Example B-1.
園 2-10]実施例 B— 2で 5回まで過充電電圧まで開放充放電を繰り返したときの蓄電 デバイスの特性を示すグラフである。 Fig. 2-10] This is a graph showing the characteristics of the electricity storage device when open charge / discharge is repeated up to the overcharge voltage up to 5 times in Example B-2.
園 2-11]比較例 B—1で 5回まで過充電電圧まで開放充放電を繰り返したときの蓄電 デバイスの特性を示すグラフである。 [Sen-2-11] This is a graph showing the characteristics of an electricity storage device when open-charge / discharge is repeated up to 5 times of overcharge voltage in Comparative Example B-1.
[図 2-14]使用時の蓄電デバイスの限界充電電位と端子間電圧を説明するための図 である。 (A)と（B)の説明は図 1の説明を参照のこと。  FIG. 2-14 is a diagram for explaining the limit charging potential and the terminal voltage of the electricity storage device during use. See the description of Figure 1 for a description of (A) and (B).
[図 3]本発明が適用される蓄電デバイスの充放電容量と電圧の関係を示すグラフ（ク
Figure imgf000012_0001
FIG. 3 is a graph showing the relationship between charge / discharge capacity and voltage of an electricity storage device to which the present invention is applied.
Figure imgf000012_0001
園 4]従来の電気二重層キャパシタの充放電容量と電圧の関係を示すグラフ（クロノ 発明を実施するための最良の形態 4] A graph showing the relationship between the charge / discharge capacity and voltage of a conventional electric double layer capacitor (the best mode for carrying out the invention)
本発明のデバイスにおいて、完全放電時に、前記負極が正電荷で逆充電された状 態になるためには（態様 A)、または完全放電時に負極が放電されずに残存する負 電荷で充電された状態になるには（態様 B)、具体的には後述するような不可逆反応 を利用する。この説明の前に、最初に、正極における電気的充電過程が、低電圧領 域におけるァニオンの吸着過程と高電圧領域におけるインターカレーシヨン過程を示 し、負極における電気的充電が、カチオンの吸着により生ずる蓄電デバイスについて 説明する。 In the device of the present invention, in order to be in a state where the negative electrode is reversely charged with a positive charge at the time of complete discharge (Aspect A), or at the time of complete discharge, the negative electrode is charged with a remaining negative charge without being discharged. To achieve the state (Aspect B), specifically, an irreversible reaction as described later is used. Before this explanation, first, the electrical charging process at the positive electrode shows the adsorption process of the anion in the low voltage region and the intercalation process in the high voltage region. An electricity storage device in which electrical charging at the negative electrode is caused by adsorption of cations will be described.
[0055] <遷移電圧を有する蓄電デバイスの説明〉  <Description of power storage device having transition voltage>
図 3に、本発明の蓄電デバイスの代表的な充放電特性を示す。また、図 4に、従来 の電気二重層キャパシタとして正極負極に活性炭を使用したデバイスの充放電特性 を、図 3に示した本発明のデバイスの特性と合わせて示す。これらの充電容量 電圧 特性曲線 (クロノポテンショグラム）のグラフでは、横軸が充放電容量を表し、縦軸が 電圧を表す。例えば定電流充電を行ったとすると、横軸は充電容量を表すと共に充 電時間にも対応する。  FIG. 3 shows typical charge / discharge characteristics of the electricity storage device of the present invention. Fig. 4 shows the charge / discharge characteristics of a device using activated carbon for the positive and negative electrodes as a conventional electric double layer capacitor, together with the characteristics of the device of the present invention shown in Fig. 3. In these graphs of the charge capacity voltage characteristic curve (chronopotentiogram), the horizontal axis represents the charge / discharge capacity, and the vertical axis represents the voltage. For example, if constant current charging is performed, the horizontal axis represents the charging capacity and also corresponds to the charging time.
[0056] 本発明の蓄電デバイスでは、図 3に示すように、充電時に電圧 Vtを境にして充電 容量 電圧特性曲線の傾斜が大きく変化する。即ち、電圧 Vtまでは正極活物質に ォニゥム塩のァニオンが吸着し、電圧 Vt以上でァニオンが正極活物質にインター力 レーシヨンしている。本出願では、充電過程が吸着からインターカレーシヨンに変わる 電圧 Vtを、遷移電圧と定義する。  In the electricity storage device of the present invention, as shown in FIG. 3, the slope of the charge capacity voltage characteristic curve changes greatly with voltage Vt as the boundary during charging. That is, the ionic salt anion is adsorbed on the positive electrode active material up to the voltage Vt, and the anion is inter-forced on the positive electrode active material at a voltage Vt or higher. In this application, the voltage Vt at which the charging process changes from adsorption to intercalation is defined as the transition voltage.
[0057] 遷移電圧 Vtまでの吸着による充電では、比表面積の小さな正極活物質に吸着され るァユオン量は少ないので充電容量は小さぐ充電容量 電圧特性曲線には、大き な傾斜が観察される。その後のインターカレーシヨンによる充電過程では、比較的電 圧の変化が小さぐ大きな電荷を取り込むことができるので、大きな蓄電容量を発現 すること力 Sでさる。  [0057] In charging by adsorption up to the transition voltage Vt, the charge capacity is small because the amount of cation adsorbed on the positive electrode active material having a small specific surface area is small. A large slope is observed in the voltage characteristic curve. In the subsequent charging process using intercalation, a large charge with a relatively small change in voltage can be taken in.
[0058] さらにインターカレーシヨンを詳細に検討すると、遷移電圧 Vt付近で、正極活物質 表面に吸着したァニオンが急速にインターカレーシヨンする過程と、その後の通常の 本格的なインターカレーシヨン過程に分けられる。遷移電圧 Vt付近での吸着ァニォ ンのインターカレーシヨンによる反応電流は小さ!/、が、狭!/、電圧域で起きるため単位 電圧当たりの容量変化量を調べると、この電圧域において反応電流は極大値または ショルダーとして検出される。ただし、正極に用いる黒鉛質材料の比表面積が小さい 場合、インター力レートする吸着ァニオン量が少ないために、明確にピークとして検 出され難いこともある。また、この蓄電デバイスを遷移電圧以上の電圧領域のみで利 用するシステムでは、その充放電の際には当然ながら見かけ上は遷移電圧 Vtが観 察されない。 [0058] Further, when the intercalation is examined in detail, it is divided into a process in which the anion adsorbed on the surface of the positive electrode active material rapidly intercalates near the transition voltage Vt and a normal full-scale intercalation process thereafter. It is done. The reaction current due to the intercalation of the adsorption anion near the transition voltage Vt is small! /, But it is narrow! /. Since this occurs in the voltage range, the reaction current in this voltage range is Detected as local maximum or shoulder. However, when the specific surface area of the graphite material used for the positive electrode is small, it may be difficult to detect clearly as a peak due to the small amount of adsorbed anion acting as an inter force. Also, in a system that uses this electricity storage device only in the voltage region above the transition voltage, the transition voltage Vt is apparently observed when charging and discharging. Not seen.
[0059] 放電時には、放電量の増加（残存容量の減少）と共に、脱インターカレーシヨンによ り緩やかに電圧が減少し、ほとんどのァニオンが脱インターカレーシヨンしたところで 急激に電圧が低下する。しかし、充電時とは異なり、脱インターカレーシヨン状態から 脱着状態に移行する過程が明瞭に発現しないために、クロノポテンショグラム上には 明確な遷移電圧は観察されなレ、。  [0059] During discharge, the voltage gradually decreases due to deintercalation as the discharge amount increases (remaining capacity decreases), and the voltage drops rapidly when most of the anions are deintercalated. However, unlike charging, the process of transition from the deintercalation state to the desorption state does not appear clearly, so no clear transition voltage is observed on the chronopotentiogram.
[0060] 本発明の蓄電デバイスでは、使用時の充放電領域として、インターカレーシヨンした 状態にて、使用されることが好ましい。図 3では、放電時に遷移電圧 Vt以下の 1. 5V まで使用可能であることを示している力 s、この状態でもインターカレーシヨンしたァニ オンが残っており、ここから再充電を始めた場合には、吸着過程を経ることなく遷移 電圧 Vt以上から充電が開始される。充電時の遷移電圧 Vtと放電時にインターカレ ーシヨン状態にあって利用できる電圧の差は、充放電時の電流と内部抵抗等の影響 も受け、通常 0. 5V程度である。 [0060] The electricity storage device of the present invention is preferably used in an intercalated state as a charge / discharge region during use. In Fig. 3, the force s indicates that it can be used up to 1.5V, which is lower than the transition voltage Vt during discharge. Even in this state, the intercalated anion remains, and recharging starts from here. In this case, charging starts from the transition voltage Vt or higher without going through the adsorption process. The difference between the transition voltage Vt at the time of charging and the voltage that can be used in the intercalation state at the time of discharging is usually about 0.5 V due to the influence of the current and internal resistance during charging and discharging.
[0061] 本発明の蓄電デバイスでは、このように放電時において高い電圧を保ちながら放電 していくので、電子機器に必要とされる電圧領域において実際に利用できる蓄電容 量が大きい。また、取り出せるエネルギー容量は、クロノポテンショグラムの積分に対 応するが、本発明のデバイスは、高い電圧で放電するために、エネルギー容量が大 きいことも特徴である。  [0061] In the electricity storage device of the present invention, discharge is performed while maintaining a high voltage during the discharge as described above, and thus the electricity storage capacity that can be actually used is large in the voltage range required for the electronic device. The energy capacity that can be extracted corresponds to the integration of the chronopotentiogram, but the device of the present invention is also characterized by a large energy capacity because it discharges at a high voltage.
[0062] 一方、従来の正極および負極に活性炭を使用した電気二重層キャパシタでは、図 4に示すように、充放電のクロノポテンショグラムがなだらかである。これは、低電圧に ても充電される容量が大きいことを示しており、本発明の蓄電デバイスに比べて、この 例では 1. 5V以下の範囲で利用できる容量が大きい。しかし、蓄電デバイスを、 1. 5 V以上で動作する電子機器に搭載したときに、 1. 5V以下の範囲で充電容量が大き いことは何ら意味がない。即ち、本発明の蓄電デバイスは、実際に使用する比較的 高電圧の範囲での充電容量、特にエネルギー容量が大き!/、ことが特徴である。  On the other hand, in the conventional electric double layer capacitor using activated carbon for the positive electrode and the negative electrode, as shown in FIG. 4, the chronopotentiogram of charge / discharge is gentle. This indicates that the capacity to be charged is large even at a low voltage. Compared with the electricity storage device of the present invention, the capacity that can be used in the range of 1.5 V or less is large in this example. However, when the electricity storage device is mounted on an electronic device that operates at 1.5 V or higher, it does not make any sense to have a large charge capacity in the range of 1.5 V or lower. That is, the electricity storage device of the present invention is characterized by a large charge capacity, particularly an energy capacity, in a relatively high voltage range that is actually used.
[0063] 本発明の蓄電デバイスの遷移電圧 Vtは、従って、実際の電子機器で使用される電 圧を考慮して定められることが好ましぐ通常 1. 5V以上に設定されることが好ましい [0064] 遷移電圧 Vtは、正極活物質の容量（capacity)と負極活物質の容量（capacity)、特 にその比に依存することから、両者の組み合わせで遷移電圧 Vtを調節することがで きる。正極活物質の容量が大きい場合、遷移電圧 Vtは低くなり、負極活物質の容量 が大きい場合には、遷移電圧 Vtは高くなる。 [0063] Therefore, the transition voltage Vt of the electricity storage device of the present invention is preferably set in consideration of the voltage used in an actual electronic device, and is usually preferably set to 1.5 V or higher. [0064] Since the transition voltage Vt depends on the capacity of the positive electrode active material and the capacity of the negative electrode active material, particularly the ratio thereof, the transition voltage Vt can be adjusted by a combination of both. . When the capacity of the positive electrode active material is large, the transition voltage Vt is low, and when the capacity of the negative electrode active material is large, the transition voltage Vt is high.
[0065] さらに、本発明の蓄電デバイスでは、例えば正極活物質および負極活物質の容量 を調整し、即ち、遷移電圧 Vtを調節することで、充電時 (即ち正極活物質へのインタ 一力レーシヨン時）に、正極における電解液の分解反応を抑制し、サイクル特性を改 善することもできる。本発明者は、従来の正極に黒鉛を用いた電気二重層キャパシタ では、正極上で電解液 (溶媒）の分解が起こり、これに伴う分解生成物の有機質が負 極側に移動して負極表面を被覆する結果、負極表面の有効な電気二重層がサイク ル毎に減少し、これが容量維持率の減少、すなわちサイクル特性低下をもたらすこと を見出した。電解液の分解の開始電圧は種々の要因に依存する力 活性炭の種類 や表面積、正極と負極の容量比等に依存する。この例の本発明の蓄電デバイスでは 、 3. 2V程度（図 3)、一方、従来の電気二重層キャパシタでは、 2. 3V程度（図 4)か らそれぞれ分解反応電流が観察されて!/、る。  [0065] Further, in the electricity storage device of the present invention, for example, by adjusting the capacities of the positive electrode active material and the negative electrode active material, that is, by adjusting the transition voltage Vt, during charging (that is, interaction with the positive electrode active material). In some cases, the decomposition reaction of the electrolyte in the positive electrode can be suppressed, and the cycle characteristics can be improved. In the conventional electric double layer capacitor in which graphite is used for the positive electrode, the inventor decomposes the electrolytic solution (solvent) on the positive electrode, and the organic substance of the decomposition products accompanying this decomposition moves to the negative electrode side. As a result of coating, it was found that the effective electric double layer on the negative electrode surface decreases with each cycle, which leads to a decrease in capacity retention rate, that is, a decrease in cycle characteristics. The starting voltage for the decomposition of the electrolyte depends on various factors, such as the type and surface area of the activated carbon, and the capacity ratio between the positive and negative electrodes. In this example of the electricity storage device of the present invention, about 3.2 V (Fig. 3), while in the conventional electric double layer capacitor, a decomposition reaction current is observed from about 2.3 V (Fig. 4), respectively! /, The
[0066] 正極上で電解液 (溶媒）の分解を抑制するための方法の 1つとして、充電の間に正 極側の電位が分解電位を超えな!/、ようにすることが有効である。  [0066] As one of the methods for suppressing the decomposition of the electrolytic solution (solvent) on the positive electrode, it is effective that the positive electrode potential does not exceed the decomposition potential during charging! .
[0067] 態様 Aの蓄電デバイスでは、例えば負極と正極の容量比を小さくして、遷移電圧を 低く設定する。充電容量が増大していく間に、正極電位の上昇が小さぐ負極電位の 絶対値の大きい範囲まで充電が可能になる。その結果、蓄電デバイスの使用可能な 電圧範囲を広くとっても、電解液分解反応が十分に抑制された電位内で使用するこ とができるようになる。このように、正極活物質における充電が、吸着とインターカレー シヨンの 2段階過程を示すことにより、態様 Aの蓄電デバイスは、利用できる放電容量 および放電エネルギーを大きくとることができる。使用時の電解液の分解も考慮する と、実装置で利用できる放電容量および放電エネルギー、並びにサイクル特性の点 でこの蓄電デバイスは極めて優れて!/、る。  [0067] In the electricity storage device of aspect A, for example, the capacitance ratio between the negative electrode and the positive electrode is reduced, and the transition voltage is set low. While the charging capacity increases, charging can be performed up to a range where the absolute value of the negative electrode potential is small and the increase in the positive electrode potential is small. As a result, even if the usable voltage range of the electricity storage device is widened, it can be used within a potential where the electrolyte decomposition reaction is sufficiently suppressed. As described above, charging in the positive electrode active material shows a two-stage process of adsorption and intercalation, so that the electricity storage device of aspect A can take a large discharge capacity and discharge energy. Considering the decomposition of the electrolyte during use, this electricity storage device is extremely excellent in terms of the discharge capacity and discharge energy that can be used in actual equipment and the cycle characteristics!
[0068] また態様 Bの蓄電デバイスでは、例えば負極と正極の容量比を大きくして、遷移電 圧を高く設定する。充電容量が増大していく間に、正極電位の上昇が小さぐ負極電 位の絶対値の大きい範囲まで充電が可能になる。その結果、デバイス電圧で見た分 解電圧が上昇する。そのために、蓄電デバイスの使用可能な電圧が高くなることに加 え、電解液分解反応が十分に抑制された電圧範囲で使用することができる。このよう な使用条件では、負極上への有機物沈積が抑制され蓄電デバイスの容量低下が改 良される結果、サイクル特性が向上する。具体的には、図 3および図 4で、正極活物 質と負極活物質の重量比を 1/1とした場合、 2200m2/g以上の高表面積を有する 活性炭を両極の活物質として用いた電気二重層キャパシタの 3. 5Vからの 0Vまでの 放電容量は本発明の蓄電デバイスを上回る。しかし、充電時に 2. 3Vで反応電流が 認められるため、充電電圧は 2. 3Vまでに限定される。一方、本発明の蓄電デバイス では、 3. 2V程度まで充電できる。従って、実際に利用する電圧範囲を、例えば 1. 5 V以上とすると、蓄電デバイスで利用できる充放電容量は 3. 2V〜； 1. 5Vの範囲であ るために、 2. 3V〜； 1. 5Vの範囲しか利用できない電気二重層キャパシタの充放電 容量を上回る。さらに放電エネルギーで比較すると逐次充電過程を示す蓄電デバィ スのそれは電気二重層キャパシタの 3倍以上となる。 [0068] In the electricity storage device of aspect B, for example, the capacitance ratio between the negative electrode and the positive electrode is increased to set the transition voltage high. While the charging capacity increases, the negative electrode power Charging is possible up to a range with a large absolute value. As a result, the resolved voltage as viewed from the device voltage increases. Therefore, in addition to the increase in the usable voltage of the electricity storage device, it can be used in a voltage range in which the electrolytic solution decomposition reaction is sufficiently suppressed. Under such conditions of use, the deposition of organic matter on the negative electrode is suppressed and the capacity reduction of the electricity storage device is improved, resulting in improved cycle characteristics. Specifically, in FIGS. 3 and 4, when the weight ratio of the positive electrode active material to the negative electrode active material is 1/1, activated carbon having a high surface area of 2200 m 2 / g or more was used as the active material for both electrodes. The discharge capacity of the electric double layer capacitor from 3.5V to 0V exceeds that of the electricity storage device of the present invention. However, since the reaction current is recognized at 2.3V during charging, the charging voltage is limited to 2.3V. On the other hand, the electricity storage device of the present invention can be charged to about 3.2V. Therefore, if the voltage range actually used is, for example, 1.5 V or more, the charge / discharge capacity that can be used in the electricity storage device is in the range of 3.2 V to; 1.5 V, so 2.3 V to 1; It exceeds the charge / discharge capacity of electric double layer capacitors that can only be used in the 5V range. Furthermore, when compared with the discharge energy, the storage device that shows the sequential charging process is more than three times the electric double layer capacitor.
[0069] 態様 Bでは、以上のように正極活物質における充電力 吸着とインターカレーシヨン の 2段階過程を示すことにより、特にその遷移電圧 Vtを比較的高めに設定することに より、態様 Bの蓄電デバイスは、利用できる放電容量および放電エネルギーを大きく とること力 Sできる。さらに電解液の分解も考慮すると、実装置で利用できる放電容量お よび放電エネルギー、並びにサイクル特性の点で、遷移電圧を有するこの蓄電デバ イスは極めて優れている。  [0069] In aspect B, by showing the two-stage process of charging power adsorption and intercalation in the positive electrode active material as described above, by setting the transition voltage Vt relatively high, it is possible to An electricity storage device can increase the available discharge capacity and discharge energy. Furthermore, considering the decomposition of the electrolyte, this storage device having a transition voltage is extremely excellent in terms of discharge capacity and discharge energy that can be used in an actual apparatus, and cycle characteristics.
[0070] <態様 A：蓄電容量を拡大する方法の説明〉  [0070] <Aspect A: Description of Method for Enlarging Storage Capacity>
本発明の態様 Aにおける容量拡大は、負極の活性炭のイオン利用率を高めること にある。このメカニズムを図 1—1〜図 1—8を参照しながら説明する。これらの図で、（ A)および (B)は同じ充放電状態を示しており、（A)は正負極の容量と電位、電圧の 関係を示すための模式図であり、横軸は電位、縦軸は静電容量 (dQ/dV)を表す。 また、（B)は電池構造の模式図であり、正極および負極が保持する電子および正孔 、並びに電荷バランスを説明する。また、負極における不可逆反応として、溶媒の還 元分解を例にとり、溶媒の還元電位を示した。 [0071] 図 1 1は、充電前の蓄電デバイスを示している。図 1 1 (B)に示すように、充電前 は、正極および負極には、ァニオンおよびカチオンは、インターカレーシヨンも吸着も していない。図 1 1 (A)において、正極および負極の四角は、高さが静電容量、横 の位置が充電可能な電位範囲、四角の面積がそれぞれの積算容量 (通常の充電で 充電できる積分電気量 mAH)を模式的に表している。尚、正極の容量は、吸着容量 とインターカレーシヨン容量の 2つの合計である。 The capacity expansion in the embodiment A of the present invention is to increase the ion utilization rate of the activated carbon of the negative electrode. This mechanism will be explained with reference to Fig. 1-1 to Fig. 1-8. In these figures, (A) and (B) show the same charge / discharge state, (A) is a schematic diagram showing the relationship between the capacity and potential of positive and negative electrodes, voltage, and the horizontal axis is potential, The vertical axis represents the capacitance (dQ / dV). (B) is a schematic diagram of the battery structure, and describes the electrons and holes held by the positive electrode and the negative electrode, and the charge balance. In addition, as an irreversible reaction in the negative electrode, the reduction potential of the solvent was shown by taking the reduction decomposition of the solvent as an example. FIG. 11 shows the electricity storage device before charging. As shown in FIG. 11 (B), before charging, the anions and cations were not intercalated or adsorbed on the positive and negative electrodes. In Fig. 11 (A), the squares of the positive and negative electrodes are the height of the capacitance, the potential position in the horizontal position is the chargeable range, and the area of the square is the accumulated capacity of each (the integrated electric charge that can be charged by normal charging) mAH) is schematically represented. The capacity of the positive electrode is the sum of the adsorption capacity and intercalation capacity.
[0072] 次に、この電池を充電していくと、図 1 2 (B)に示すように、正極から負極へ電子 が移動し、負極に電子が蓄積され正極に正孔が蓄積される。また負極表面にはカチ オンが吸着され、正極にはァニオンがインターカレーシヨンしている。図 1 2 (A)に は、正極、負極の容量が部分的に充電された様子を示す。  Next, when this battery is charged, as shown in FIG. 12 (B), electrons move from the positive electrode to the negative electrode, electrons are accumulated in the negative electrode, and holes are accumulated in the positive electrode. Catonion is adsorbed on the negative electrode surface, and anion is intercalated on the positive electrode. Figure 12 (A) shows the state where the positive and negative electrode capacities were partially charged.
[0073] さらに充電を進め、負極側で不可逆反応開始電位 (この例では溶媒の還元分解電 位）にちようど達した状態、即ち、負極が充電可能な積算容量に達した状態を図 1— 3に示す。図 1 3 (B)に示すように、正極力、ら負極に N個の電子が流れ、負極には N 個の電子が蓄積され、正極には N個の正孔が蓄積されている。このとき、図 1 3 (A) に示すように、負極の積算容量は全部充電されているが、正極には未だ充電可能な 容量が残存している（図中の「余裕部分」）。このような状態は、正極の積算容量が負 極の積算容量より大きくなるように設定することで、達成できる。  [0073] Charging is further advanced, and the state in which the irreversible reaction starting potential (in this example, the reductive decomposition potential of the solvent) is reached on the negative electrode side, that is, the state in which the negative electrode has reached a chargeable integrated capacity is shown in FIG. — Shown in 3. As shown in Fig. 13 (B), N electrons flow in the negative electrode due to the positive force, N electrons accumulate in the negative electrode, and N holes accumulate in the positive electrode. At this time, as shown in FIG. 13 (A), the accumulated capacity of the negative electrode is fully charged, but the chargeable capacity still remains in the positive electrode (“extra portion” in the figure). Such a state can be achieved by setting the accumulated capacity of the positive electrode to be larger than the accumulated capacity of the negative electrode.
[0074] 正極積算容量/負極積算容量比は、好ましくは 1.；!〜 2. 0の範囲である。積算容 量比が 2. 0を超えても本態様の効果は発現するが、積算容量比が 2. 0以上では充 放電に関与しない正極活物質量が過多となり、デバイスの容量が低下することとなる 。さらに好ましくは、正極積算容量/負極積算容量比は 1. 2〜； 1. 6である。  [0074] The positive electrode cumulative capacity / negative electrode cumulative capacity ratio is preferably in the range of 1.;! ~ 2.0. The effect of this aspect is exhibited even when the integrated capacity ratio exceeds 2.0, but when the integrated capacity ratio is 2.0 or more, the amount of the positive electrode active material not involved in charge / discharge becomes excessive, and the device capacity decreases. Become. More preferably, the positive electrode integrated capacity / negative electrode integrated capacity ratio is 1.2 to 1.6.
[0075] 正極積算容量/負極積算容量比は、材料の選択（単位重量あたりの容量の大きな 材料または小さな材料の選択）と共に、正極と負極の重量比を変えることで達成でき  [0075] The positive electrode cumulative capacity / negative electrode cumulative capacity ratio can be achieved by changing the weight ratio of the positive electrode and the negative electrode together with the selection of materials (selection of a material with a large capacity per unit weight or a small material).
[0076] そこで、使用する溶媒系にも依存するが、例えば正極電位を 5. 5V vs. Li+/Li 以下（好ましくは 5. 2V以下）、負極電位を 1. 9V vs. Li+/Li以下とし、両極間の 電圧を 3. 3V以上に設定することによって、負極表面で電解液の不可逆的な分解反 応が起きる。そこで、図 1 4に示すように、仮に両極間の充電電圧を 3. 5Vとして充 電すると、正極容量より負極容量を小さく設計した本態様の蓄電デバイスでは、過充 電によって負極で電解液の還元分解が起き、 n個の電子が消費される。このとき正極 では等価の n個の電子が抜けた結果、この電荷に相当する n個の正孔が加わり、合 計 N + n個の正孔が蓄積され、これに見合うァニオンがインターカレーシヨンする。 Therefore, depending on the solvent system used, for example, the positive electrode potential is 5.5 V vs. Li + / Li or less (preferably 5.2 V or less), and the negative electrode potential is 1.9 V vs. Li + / Li. By setting the voltage between the two electrodes to 3.3 V or higher as follows, an irreversible decomposition reaction of the electrolyte occurs on the negative electrode surface. Therefore, as shown in Fig. 14, the charging voltage between both electrodes is assumed to be 3.5V. When charged, in the electricity storage device of this embodiment designed to have a negative electrode capacity smaller than the positive electrode capacity, reductive decomposition of the electrolyte solution occurs at the negative electrode due to overcharging, and n electrons are consumed. At this time, as a result of the elimination of equivalent n electrons at the positive electrode, n holes corresponding to this charge are added, a total of N + n holes are accumulated, and anion corresponding to this is intercalated. .
[0077] ここまで、過充電した後、放電する。図 1 5は、充電された N個の電子が放電され た状態までを示す。負極側に、 N + n個の電子が流れたにもかかわらず、放電できる 電子数は反応電流量を差し引いた値の N個である。正極には N個の電子が流入し、 n個の正孔が正極に残る。  [0077] So far, the battery is discharged after being overcharged. Figure 15 shows the state until the charged N electrons are discharged. Despite N + n electrons flowing on the negative electrode side, the number of electrons that can be discharged is N minus the amount of reaction current. N electrons flow into the positive electrode, leaving n holes on the positive electrode.
[0078] し力、し、この状態では、正極と負極の電位がバランスしていないので、さらに放電が 進む。図 1 6に完全放電した状態を示す。図 1 5で正極に偏在していた n個の正 孔が有する電荷量を Qとすると、完全放電した状態（図 1 6)では、 Qは正極と負 極の静電容量に比例して分配され、電位のバランスが行われる。正極の吸着部分の 静電容量を Cc、分配される電圧を Vc、負極の吸着部分の静電容量を Ca、分配さ れる電圧を Vaとすると  In this state, since the potentials of the positive electrode and the negative electrode are not balanced, the discharge further proceeds. Figure 16 shows the fully discharged state. Assuming that the charge quantity of the n positive holes unevenly distributed in the positive electrode in Fig. 15 is Q, in the fully discharged state (Fig. 16), Q is distributed in proportion to the positive and negative electrostatic capacities. The potential is balanced. Let Cc be the electrostatic capacity of the adsorption part of the positive electrode, Vc be the distributed voltage, Ca be the electrostatic capacity of the adsorption part of the negative electrode, and Va be the distributed voltage.
Q = Qa + Qc  Q = Qa + Qc
Va =Vc
Figure imgf000018_0001
Va = Vc
Figure imgf000018_0001
が成り立つ条件で電荷と電圧がバランスする。  The charge and voltage are balanced under the condition that holds.
[0079] 図 1 6においても、負極の容量を表す四角の高さが、正極の吸着による容量を表 す四角の高さより非常に高く示しているように、現実には負極活物質として使用され る活性炭の静電容量は、正極活物質として使用される黒鉛の吸着部分の静電容量 に比較してはるかに大きい。そうすると、 [0079] In FIG. 16 as well, the square height representing the capacity of the negative electrode is actually used as a negative electrode active material, as indicated by the height of the square representing the capacity due to adsorption of the positive electrode. The capacitance of activated carbon is much larger than the capacitance of the adsorption part of graphite used as the positive electrode active material. Then
Q = Qa > > Qc = 0  Q = Qa>> Qc = 0
が成立し、完全に放電した状態すなわち電圧がバランスした時点では、図 1 5で正 極に偏在していた n個の正孔のほとんどは負極側に移動し、図 1 6 (B)に示すよう に、負極に正孔が存在し、図 1 6 (A)に示すように、正の電荷が負極に存在する。 完全放電時に負極に存在する正電荷は、電気容量の増加分として働く。また負極に おいては正電荷の容量増加によって、図 1 6 (A)に示すように、従来の等電点より 、容量増加分 Qa^電圧として だけ高電位に等電点がシフトしてバランスしている 。またそのため、正極のインターカレーシヨン開始電圧は、従来より Vaだけ低くなる。 In the fully discharged state, that is, when the voltage is balanced, most of the n holes that are unevenly distributed in the positive pole in Fig. 15 move to the negative pole side, as shown in Fig. 16 (B). Thus, there are holes in the negative electrode, and positive charges are present in the negative electrode as shown in FIG. The positive charge existing in the negative electrode during complete discharge works as an increase in electric capacity. In addition, due to the increase in the positive charge capacity at the negative electrode, as shown in Fig. 16 (A), The isoelectric point shifts to a high potential and balances only as the capacity increase Qa ^ voltage. For this reason, the intercalation start voltage of the positive electrode is lower by Va than before.
[0080] このように不可逆反応が起きる電圧で、 1回充放電を行うと、蓄電デバイスの容量と して、図 1 1(A)の負極の四角で模式的に示した元々の負極の積算容量に加えて 、 Qaだけ充放電可能な容量が増加したことになる。  [0080] When charging / discharging is performed once at such a voltage at which an irreversible reaction occurs, the capacity of the electricity storage device is calculated as the integration of the original negative electrode schematically shown by the negative electrode square in Fig. 11 (A). In addition to capacity, Qa will increase the capacity that can be charged and discharged.
[0081] 本態様では、過充電を 1回だけ行ってもよいが、複数回行ってもよい。ここでは、引 き続き 2回目の過充電を行う例を説明する。  [0081] In this embodiment, overcharging may be performed only once, but may be performed multiple times. Here, an example of continuing the second overcharge will be described.
[0082] 2回目の過充電では、 1回目の過充電と同様の操作を行う。 2回目の過充電におい ても不可逆反応が起こるように、負極側で不可逆反応開始電位 (この例では溶媒の 還元分解電位）を超えるように充電を行う。図 1— 7に示すように、仮に 1回目の過充 電と同じように、両極間に充電電圧が 3. 5Vになるまで充電すると、電解液の分解、 すなわち過充電が開始する。ここで、例えば m個の電子が電解液の分解に新たに消 費されたとすると、正極では m個の正孔が蓄えられる。この状態では、負極に蓄積さ れている電子が N個であるのに対して、正極で蓄積されている正孔は N + n + m個で ある。尚、ここで m = nとなるようにしてもよい。  [0082] In the second overcharge, the same operation as in the first overcharge is performed. Charge so that the irreversible reaction start potential (in this example, reductive decomposition potential of the solvent) is exceeded on the negative electrode side so that an irreversible reaction occurs even in the second overcharge. As shown in Figure 1-7, as with the first overcharge, if the battery is charged between both electrodes until the charge voltage reaches 3.5 V, then the electrolyte will begin to decompose, ie overcharge. Here, for example, if m electrons are newly consumed for decomposition of the electrolyte, m holes are stored in the positive electrode. In this state, the number of electrons stored in the negative electrode is N, whereas the number of holes stored in the positive electrode is N + n + m. Here, m = n may be satisfied.
[0083] そこで、完全放電を行うと、 n + m個の正孔が有する電荷 Q +Q 1 正極と負極の  [0083] Therefore, when complete discharge is performed, the charge of n + m holes Q + Q 1 between the positive and negative electrodes
1 2  1 2
静電容量に比例して分配され、電位のバランスが行われる。 1回目の完全放電後と 同様に、 Q +Q =Qa +Qc +Qa +Qc  It is distributed in proportion to the capacitance, and the potential is balanced. Q + Q = Qa + Qc + Qa + Qc as after the first full discharge
1 2 1 1 1 2  1 2 1 1 1 2
Va +Va =Vc +Vc  Va + Va = Vc + Vc
1 2 1 2  1 2 1 2
Va +Va =(Qa +Qa )/Ca=(Qc +Qc )/Cc=Vc +Vc  Va + Va = (Qa + Qa) / Ca = (Qc + Qc) / Cc = Vc + Vc
1 2 1 2 1 2 1 2  1 2 1 2 1 2 1 2
が成り立つ条件で電荷と電圧がバランスする。負極の静電容量が正極の静電容量よ りはるかに大きいので、  The charge and voltage are balanced under the condition that holds. Since the negative electrode capacitance is much larger than the positive electrode capacitance,
Q +Q =Qa +Qa > >Qc +Qc =0  Q + Q = Qa + Qa>> Qc + Qc = 0
1 2 1 2 1 2  1 2 1 2 1 2
が成り立つ結果、完全に放電した状態すなわち電圧がバランスした時点では、図 1 8(B)に示すように、 n + m個の正孔のほとんどは負極側に移動する。図 1 8(A)に 示すように、この結果、完全放電時に負極に存在する正電荷は、電気容量の増加分 として働く。但し、正極における充電過程が吸着からインターカレーシヨンに変わる遷 移電圧は、この例では、 Va +Vaだけ、低下している。 [0084] このように、不可逆反応が起きる電圧での 1回または複数回の開放充放電を行うと、 充放電が可能な容量が増加するので、大きな容量を有する蓄電デバイスを製造する こと力 Sでさる。 As a result, in a completely discharged state, that is, when the voltage is balanced, as shown in FIG. 18 (B), most of the n + m holes move to the negative electrode side. As shown in Fig. 18 (A), as a result, the positive charge present on the negative electrode during full discharge works as an increase in capacitance. However, the transition voltage at which the charging process at the positive electrode changes from adsorption to intercalation is reduced by Va + Va in this example. [0084] As described above, when one or more open charge / discharge operations are performed at a voltage at which an irreversible reaction occurs, the chargeable / dischargeable capacity increases, and thus it is possible to manufacture a power storage device having a large capacity. I'll do it.
[0085] 図 1 9は、本態様の蓄電デバイスで、過充電による開放充放電を 10回繰り返し、 そのとき充放電曲線から得られる dQ/dV曲線である（後述する実施例 A— 1)。この 図で、上の曲線群が充電過程を示し、（1)は 1回目の充電、（10)は 10回目の充電を 示す。また、下の曲線群が放電過程を示す。この図から不可逆反応が起こる範囲で の充放電を繰り返すと、正極でインターカレーシヨンによる充電が開始する電圧は低 下している（充電時の dQ/dV曲線の立ち上がり電圧が低下している）。一方、充電 容量は、充電時の dQ/dV曲線の積分値であるから、 10回の過充電を繰り返した蓄 電デバイスでは、充電容量が増加して!/、ること力 Sわ力、る。  [0085] FIG. 19 is a dQ / dV curve obtained from the charge / discharge curve in the electricity storage device of this embodiment, in which open charge / discharge by overcharge is repeated 10 times (Example A-1 described later). In this figure, the upper curve group shows the charging process, (1) shows the first charge, and (10) shows the 10th charge. The lower curve group shows the discharge process. From this figure, if charging and discharging are repeated within the range where irreversible reaction occurs, the voltage at which charging by intercalation starts at the positive electrode decreases (the rising voltage of the dQ / dV curve during charging decreases) . On the other hand, the charge capacity is the integral value of the dQ / dV curve at the time of charge, so in a storage device that has been repeatedly overcharged 10 times, the charge capacity increases! .
[0086] また、本態様の蓄電デバイスでは、その特有の充放電メカニズムに基づいて、 dQ /dV曲線が特有の形状を示している。図 1—9から、 1回目の過充電と 10回目の過 充電過程の dQ/dV曲線を抜き出したグラフを図 1— 10に示す。 1回目の充電では 、充電過程力 Sインターカレーシヨンに基づく電圧に達したときに、曲線が立ち上がつ た後、電圧の上昇と共に dQ/dVが上昇している。一方、 10回目の充電では、 dQ/ dV値は、充電電圧 Vが上昇し正極でのァニオンのインターカレーシヨンが開始され た直後に極大を示した後、 dQ/dV値が漸減し（図中、 A部）、 dQ/dV値が極小値 を得た後再び漸増する。本態様の蓄電デバイスでは、不可逆反応が起こる電圧での 開放充放電を経て製造されているので、通常の使用時の充電過程でも、上記の特有 のグラフ形状が観察される。  [0086] Further, in the electricity storage device of this embodiment, the dQ / dV curve shows a specific shape based on the specific charge / discharge mechanism. Figure 1-10 shows a graph of the dQ / dV curves extracted from the 1st overcharge and 10th overcharge processes from Figure 1-9. In the first charge, when the voltage based on the charging process force S intercalation is reached, the dQ / dV increases as the voltage rises after the curve rises. On the other hand, in the 10th charge, the dQ / dV value gradually decreased immediately after the charge voltage V increased and the canyon intercalation at the positive electrode started, and then the dQ / dV value gradually decreased (in the figure). , Part A), dQ / dV increases gradually again after obtaining the minimum value. Since the electricity storage device of this embodiment is manufactured through open charge / discharge at a voltage at which an irreversible reaction occurs, the above-mentioned characteristic graph shape is observed even during the charge process during normal use.
[0087] 本態様の蓄電デバイスの充電過程の dQ/dVが特有の形状を示すのは次の理由 による。まず、図 1 1〜図 1 8で、負極の容量を四角で表し、電圧によって電圧当 たりの容量 (dQ/dV)が一定であると仮定して説明してきた。しかし、実際の負極活 性炭の吸着電位に対する容量は、図 1 11に示すように、等電点を中心にして電位 が離れるほど大きくなる。図 1 8 (A)の負極の容量を修正して模式的に示すと図 1 —12のように表すこと力 Sできる。図 1— 11および図 1— 12に示すように、本態様の蓄 電デバイスでは、充電開始後に、 dQ/dV値の低下が必然的の起こるために、実際 の dQ/dV曲線では、インターカレーシヨンが開始された直後に極大を示した後、 dQ /dV値が漸減するという特徴的な形状が表れる。一方、不可逆反応が起こる電圧で の過充電を行わな!/、蓄電デバイスでは、図 1 11に示すように充電時に dQ/dV値 の減少がないために、インターカレーシヨンが開始した後にも単調に上昇が続く。 [0087] The reason why dQ / dV in the charging process of the electricity storage device of this embodiment shows a specific shape is as follows. First, in FIGS. 11 to 18, the capacity of the negative electrode is represented by a square, and it has been assumed that the capacity per voltage (dQ / dV) is constant depending on the voltage. However, the capacity of the actual negative active carbon for the adsorption potential increases as the potential increases with the isoelectric point as the center, as shown in Fig. 111. Fig. 1 8 When the capacity of the negative electrode in (A) is modified and shown schematically, the force S can be expressed as shown in Fig. 1-12. As shown in Fig. 1-11 and Fig. 1-12, in the storage device of this embodiment, the dQ / dV value is inevitably lowered after the start of charging. The dQ / dV curve shows a characteristic shape in which the dQ / dV value gradually decreases after showing the maximum immediately after the start of intercalation. On the other hand, do not overcharge at a voltage that causes an irreversible reaction! /, Because the storage device has no decrease in dQ / dV value during charging as shown in Figure 111, it is monotonous even after the start of intercalation. The rise continues.
[0088] 本態様の蓄電デバイスでは、上記過充電を開放充電の段階で行うことが好まし!/、。  [0088] In the electricity storage device of this embodiment, it is preferable to perform the overcharge at the stage of open charge! /.
そして、実際の使用時の充電では電解液が分解しない正極電位、負極電位および 端子間電圧に設定することが好ましい。図 1 15に、実際の使用時 (定常状態）にお ける限界充電電位と端子間電圧を示す。図中の「充電下限界電位」は溶媒の還元分 解が始まる限界の電位であり、この例では、 1. 7Vvs. Li+/Liである。充電時に、負 極側で「充電下限界電位」を下回るまで充電を行うと、溶媒の還元分解が起こるので 、「充電下限界電位」が負極側の充電時の下限電位である。従って、使用時には、負 極電位が「充電下限界電位」を下回らない範囲で充電を行う。負極の充電電位は、 具体的には 1 · 7Vvs. Li+/Li以上が好ましぐ特に 1 · 9Vvs. Li+/Li以上が好ま しい。一方、図中の「充電上限界電位」は、溶媒の酸化分解反応が開始する正極電 位または負極が「充電下限界電位」に達したときの正極電位のどちらか低い方である 。図 1 15で示す例では、負極が「充電下限界電位」に達したときに、正極電位が 4 . 9Vvs. Li+/Liの「充電上限界電位」に達する。従って、使用時には、正極電位が 「充電上限界電位」を超えない範囲、少なくとも溶媒の酸化分解反応が起こらない正 極電位で充電を行う。正極の充電電位は、具体的には 5. 2Vvs. Li+/Li以下が好 ましぐさらに 4. 9Vvs. Li+/Li以下が好ましい。例えば4. 6〜5· 2Vvs. Li+/Li の範囲で充電されるように使用する。 And, it is preferable to set the positive electrode potential, the negative electrode potential, and the inter-terminal voltage at which the electrolyte does not decompose during actual use charging. Figure 115 shows the limit charging potential and terminal voltage during actual use (steady state). The “limit potential under charge” in the figure is the limit potential at which the reductive decomposition of the solvent begins. In this example, it is 1.7 Vvs. Li + / Li. At the time of charging, if the battery is charged until it falls below the “lower limit potential” on the negative electrode side, reductive decomposition of the solvent occurs. Therefore, the “lower limit potential” is the lower limit potential when charging on the negative electrode side. Therefore, during use, charging is performed within the range where the negative potential does not fall below the “lower limit potential for charging”. Charging potential of the negative electrode is specifically 1 · 7Vvs. Li + / Li or preferably tool particularly 1 · 9Vvs. Li + / Li or favored arbitrarily. On the other hand, the “charging upper limit potential” in the figure is the lower one of the positive electrode potential at which the oxidative decomposition reaction of the solvent starts and the negative electrode potential when the negative electrode reaches the “lower charging limit potential”. In the example shown in FIG. 115, when the negative electrode reaches the “lower limit potential”, the positive potential reaches the “upper limit potential” of 4.9 Vvs. Li + / Li. Therefore, during use, charging is performed at a positive electrode potential that does not cause the oxidative decomposition reaction of the solvent at least in a range where the positive electrode potential does not exceed the “limit potential for charging”. The charge potential of the positive electrode is specifically 5. 2Vvs. Li + / Li in less good Mashigusa et 4. 9Vvs. Li + / Li or less. For example 4. 6~5 · 2Vvs. Use to be charged in a range of Li + / Li.
[0089] このような条件から、充電電圧（正極と負極の端子間電圧）として、電解液が分解し ない電圧は 3. 5V以下、好ましくは 3. 4V以下、さらに好ましくは 3. 2V以下である。 この条件で充放電を行うことにより、本蓄電デバイスの容量は、上記処理を行わない デバイスと比較して、典型的には 10〜60%程度増加することができる。好ましい例で は、 15%〜50%程度増加させる。  [0089] Under such conditions, as the charging voltage (voltage between the positive and negative terminals), the voltage at which the electrolyte does not decompose is 3.5 V or less, preferably 3.4 V or less, more preferably 3.2 V or less. is there. By performing charging and discharging under these conditions, the capacity of the electricity storage device can typically be increased by about 10 to 60% compared to a device that does not perform the above treatment. In a preferred example, it is increased by about 15% to 50%.
[0090] 正負極とも活性炭を用いる従来型電気二重層キャパシタすなわち対称キャパシタ の場合、正極または負極で起きる可逆反応容量分をキャンセルするために、どちらか の電極重量をわずかに多くすることはある。し力も従来型電気二重層キャパシタにお いて開放充電でどちらかの極で溶媒の分解等の不可逆反応が起きる電圧で充電を 行っても、キャパシタの容量を増加させることは出来ない。なぜなら正負極とも活性炭 を用いる対称キャパシタでは充放電による電荷の増減、電位の変化は基本的に対称 であるからである。 [0090] In the case of a conventional electric double layer capacitor that uses activated carbon for both positive and negative electrodes, that is, a symmetrical capacitor, in order to cancel the reversible reaction capacity occurring at the positive electrode or the negative electrode, The electrode weight may be slightly increased. However, in a conventional electric double layer capacitor, even if charging is performed at a voltage at which an irreversible reaction such as decomposition of the solvent occurs at one of the electrodes, the capacity of the capacitor cannot be increased. This is because, in a symmetric capacitor using activated carbon for both positive and negative electrodes, the increase and decrease in charge and the change in potential due to charge and discharge are basically symmetric.
[0091] これに対して、本態様の蓄電デバイスでは、正極での充電過程が吸着からインター カレーシヨンに変化する遷移電圧が高ぐかつ非対称蓄電デバイスでは、負極で不 可逆反応が起きると、反応に係わる電荷が正極に蓄えられ、かつ電位を同一にする ためには遷移電圧の一部を利用して、負極に正の電荷を蓄えることが可能である。  [0091] In contrast, in the electricity storage device of this aspect, the transition voltage at which the charging process at the positive electrode changes from adsorption to intercalation is high, and in the asymmetric electricity storage device, when an irreversible reaction occurs at the negative electrode, In order to store the charge related to the positive electrode and make the potential the same, it is possible to store a positive charge on the negative electrode by using a part of the transition voltage.
[0092] 本態様の蓄電デバイスは、ァニオンのインターカレーシヨンが開始する電圧（遷移 電圧）が 1. 5〜2V程度であるもの力 さらに低電圧域での電圧を利用することができ る。遷移電圧が高いことは本態様のデバイスの動作電圧が高ぐ高エネルギーである ことを示すものではある力 本態様では、より低電圧域までの電圧区間を利用してさ らに高容量化を図るものである。  [0092] The power storage device of this embodiment can use a voltage with which a voltage (transition voltage) at which anion intercalation starts is about 1.5 to 2 V, and a voltage in a low voltage region. A high transition voltage indicates that the operating voltage of the device of this mode is high and high energy. In this mode, the capacity is further increased by using a voltage section up to a lower voltage range. It is intended.
[0093] また本態様により拡大する負極の動作電圧範囲は、負極が本来有する吸着に基づ く動作電圧範囲の 10%以上とすることが好ましぐより好ましくは、 15%以上である。 本態様の方法により負極容量が増大することによって、エネルギーは 10〜30%程度 増加する。また、負極の容量を拡大しすぎると、インターカレーシヨンが開始する遷移 電圧が低下しすぎてしまうので、遷移電圧が 1. 5V以上あるように、好ましくは 1. 7V 以上あるように設定することが好ましい。例えば、拡大する負極の動作電圧範囲は、 好ましくは 60%以下、さらに好ましくは 50%以下となるようにする。  [0093] The operating voltage range of the negative electrode expanded according to this embodiment is preferably 10% or more of the operating voltage range based on the adsorption inherent in the negative electrode, more preferably 15% or more. By increasing the negative electrode capacity by the method of this embodiment, the energy increases by about 10 to 30%. Also, if the capacity of the negative electrode is increased too much, the transition voltage at which intercalation starts will decrease too much, so the transition voltage should be set to 1.5 V or higher, preferably 1.7 V or higher. Is preferred. For example, the operating voltage range of the expanding negative electrode is preferably 60% or less, more preferably 50% or less.
[0094] 以上の説明では、不可逆反応が、溶媒の還元分解よつて起こる場合を例に挙げた 力 溶媒の還元分解に限られず、過充電によって負極で不可逆反応が起こるような 反応が利用できる。即ち、電池性能に悪影響を与えずに、負極で電子を消費するよ うな反応であればどのような反応であってもよレ、。  In the above description, the case where the irreversible reaction occurs by reductive decomposition of the solvent is exemplified. The reaction is not limited to the reductive decomposition of the solvent, and a reaction in which the irreversible reaction occurs at the negative electrode by overcharge can be used. In other words, any reaction that consumes electrons at the negative electrode without adversely affecting battery performance is acceptable.
[0095] また、過充電を行う電圧は、不可逆反応が起きる電圧に依存して適宜決められる。  In addition, the voltage for overcharging is appropriately determined depending on the voltage at which irreversible reaction occurs.
溶媒の還元分解でも、溶媒によって分解電圧が異なるので、電解液に含まれる溶媒 成分に依存して決めることが好ましレ、。 [0096] また、不可逆反応を起こすための過充電を複数回に分ける場合には、 1回での過 充電で必要な容量増大を得る場合に比べ、マイルドな条件を選択することが可能で あるので、一般には 2回以上、好ましくは 5回以上である。また、回数は特に制限され ないが、作業上、例えば 50回以下程度が好ましい。 Even in reductive decomposition of solvents, the decomposition voltage differs depending on the solvent, so it is preferable to determine it depending on the solvent components contained in the electrolyte. [0096] When overcharging for causing an irreversible reaction is divided into a plurality of times, it is possible to select milder conditions than in the case of obtaining a necessary capacity increase by one overcharging. Therefore, it is generally 2 times or more, preferably 5 times or more. Further, the number of times is not particularly limited, but it is preferably about 50 times or less for work.
[0097] 以上のような過充電および放電は、製品としてデバイスが完成する前の段階におい て、開放状態にて行うことが好ましい。このような工程を経て、製品としての蓄電デバ イスが完成する。  [0097] Overcharging and discharging as described above are preferably performed in an open state before the device is completed as a product. Through these processes, the product electricity storage device is completed.
[0098] 本態様の蓄電デバイスは高容量で充放電が可能であることから、高エネルギーを 蓄電することが可能である。その用途はパソコンのバックアップ電源、携帯電話、携 帯用モパイル機器、デジタルカメラの電源などに用いることが可能である。また、本態 様の蓄電デバイスは電気自動車や HEVの動力システムにも適用することができる。  [0098] Since the electricity storage device of this aspect can be charged and discharged with high capacity, it is possible to store high energy. It can be used for backup power sources for personal computers, mobile phones, mobile mopile devices, and power sources for digital cameras. The power storage device of this mode can also be applied to electric vehicles and HEV power systems.
[0099] 特に高電圧を必要とする動力系で用いられる場合、本蓄電デバイスの放電電圧は 1. 5V以上、望ましくは 2V以上でカットすることが好ましい。  [0099] In particular, when used in a power system that requires a high voltage, the discharge voltage of the electricity storage device is preferably 1.5 V or higher, and more preferably 2 V or higher.
[0100] また、本態様の蓄電デバイスと、充放電力 sインターカレーシヨンの領域のみとなるよ うに、所定電圧まで低下したときにシャットダウンするような、公知の電圧制御手段と を組み合わせて、蓄電システムとすることも好ましい。  [0100] In addition, the power storage device of this aspect is combined with a known voltage control means that shuts down when the voltage decreases to a predetermined voltage so that only the charge / discharge power s intercalation region is present. A system is also preferable.
[0101] さらに、本態様の蓄電デバイスが、使用時の充電時に、正極電位および負極電位 が前述の範囲になるように、端子間電圧を所定の電圧範囲に制限するように、公知 の電圧制御手段とを組み合わせて、蓄電システムとすることも好ましレ、。  [0101] Furthermore, the power storage device of this aspect is a known voltage control so that the terminal voltage is limited to a predetermined voltage range so that the positive electrode potential and the negative electrode potential are in the above-described range during charging in use. It is also preferable to combine the means into a power storage system.
[0102] <態様 Bの蓄電デバイスおよび高電圧化の方法の説明〉  <Description of power storage device of aspect B and method for increasing voltage>
本態様 Bの蓄電デバイスは、上述の遷移電圧を有する蓄電デバイスをさらに改良し 、遷移電圧を上昇させ、さらに高電圧での利用を可能にする。ァニオンのインター力 レーシヨンは化学反応であることからインターカレーシヨン電位を変えることは出来な い。遷移電圧を高くすることは正極のインターカレーシヨン開始時の負極の電位を下 げることを意味する。本態様 Bでは、負極が、放電されずに残存する負電荷で充電さ れているために、負極の電位が下げられている。そのため、高電圧で動作させも、正 極が電解液の酸化分解電位に達しないためにサイクル特性が向上する。  The electricity storage device of the present aspect B further improves the electricity storage device having the above-described transition voltage, increases the transition voltage, and enables use at a higher voltage. Since the anion force force is a chemical reaction, the intercalation potential cannot be changed. Increasing the transition voltage means lowering the negative electrode potential at the start of positive electrode intercalation. In this embodiment B, since the negative electrode is charged with the remaining negative charge without being discharged, the potential of the negative electrode is lowered. Therefore, even when operated at a high voltage, the positive electrode does not reach the oxidative decomposition potential of the electrolytic solution, so that the cycle characteristics are improved.
[0103] 高電圧動作の蓄電デバイスとするためには遷移電圧が高いことが好ましぐ 1. 75 V以上、好ましくは 2V以上、さらには 2. 2V以上であることがさらに好ましい。また、従 来のインターカレーシヨンを伴うデバイスでは、過度のインターカレーシヨンによるサイ クル特性の低下という欠点が内在する力 本態様 Bでは、実用に供しない低電圧域 での正極に対するァニオンのインターカレーシヨン負荷を減らすことができるために、 この機構によるサイクル特性も改善することができる。 [0103] A high transition voltage is preferred for a high voltage storage device 1. 75 V or more, preferably 2 V or more, more preferably 2.2 V or more. In addition, in devices with conventional intercalation, there is an inherent disadvantage that the cycle characteristics are deteriorated due to excessive intercalation. In this mode B, the anion intercalation with respect to the positive electrode in the low voltage range that is not practically used. Since the Chillon load can be reduced, the cycle characteristics by this mechanism can also be improved.
[0104] 本態様 Bの正極の活物質としては、代表的にはァニオンのインターカレーシヨンが 可能な黒鉛質材料が用いられ、また負極の活物質としては、代表的にはカチオンの 吸着可能な活性炭が用いられる。正極のインターカレーシヨン容量を静電容量として 表現すると、正極黒鉛の静電容量は活性炭の 5倍から 15倍程度と大きぐ本態様 B の蓄電デバイスは活性炭を活物質とする従来の電気二重層キャパシタに比べてはは るかに高!/、蓄電容量を有する。本蓄電デバイスの放電容量は負極にぉレ、て分極した カチオンの活性炭への吸着量と、ァニオンが黒鉛にインターカレーシヨンする量によ つて決定される。しかしインターカレーシヨンするァニオン量は、負極で分極したカチ オンと同電気量であることから、デバイス容量は電解質を分極させる負極の容量で決 定されるといえる。従って、本態様 Bの蓄電デバイスにおいては出来る限り高容量の 活性炭を選択すべきである。  [0104] As the active material of the positive electrode of this embodiment B, a graphite material capable of intercalation of anion is typically used, and as the active material of the negative electrode, a cation can be adsorbed typically. Activated carbon is used. Expressing the intercalation capacity of the positive electrode as an electrostatic capacity, the electrostatic capacity of the positive electrode graphite is about 5 to 15 times that of activated carbon. The electricity storage device of this embodiment B is a conventional electric double layer using activated carbon as an active material. Compared to capacitors, it is much higher! / And has a storage capacity. The discharge capacity of this electricity storage device is determined by the amount of adsorption of the cations polarized on the negative electrode on the activated carbon and the amount of anion intercalated into the graphite. However, since the amount of anion to be intercalated is the same amount of electricity as the negatively polarized cation, it can be said that the device capacity is determined by the capacity of the negative electrode that polarizes the electrolyte. Therefore, activated carbon having the highest capacity should be selected for the electricity storage device of this embodiment B.
[0105] 本態様 Bの高電圧化のメカニズムを図 2—1〜図 2— 8を参照しながら説明する。こ れらの図で、（A)および (B)は同じ状態を示しており、（A)は正負極の容量と電位、 電圧の関係を示すための模式図であり、横軸は電位、縦軸は静電容量 (dQ/dV)を 表す。また、（B)は電池構造の模式図であり、正極および負極が保持する電子およ び正孔、並びに電荷バランスを説明する。また、正極における不可逆反応として、溶 媒の酸化分解を例にとり、高電位側に溶媒の酸化電位、低電位側に溶媒の還元電 [0105] The mechanism for increasing the voltage in Mode B will be described with reference to Figs. 2-1 to 2-8. In these figures, (A) and (B) show the same state, (A) is a schematic diagram showing the relationship between the capacity and potential of positive and negative electrodes, voltage, the horizontal axis is the potential, The vertical axis represents the capacitance (dQ / dV). (B) is a schematic diagram of the battery structure, and explains the electrons and holes held by the positive electrode and the negative electrode, and the charge balance. As an irreversible reaction at the positive electrode, oxidative decomposition of the solvent is taken as an example. The oxidation potential of the solvent is on the high potential side and the reduction potential of the solvent is on the low potential side.
1AIを示した。 1AI was shown.
[0106] 図 2— 1は、充電前の蓄電デバイスを示している。図 2— 1 (B)に示すように、充電前 は、正極および負極には、ァニオンおよびカチオンは、インターカレーシヨンも吸着も していない。図 2— 1 (A)において、正極および負極の四角は、高さが静電容量、横 の位置が充電可能な電位範囲、四角の面積がそれぞれの積算容量 (通常の充電で 充電できる積分電気量 mAH)を模式的に表している。尚、正極の容量は、吸着容量 とインターカレーシヨン容量の 2つの合計である。 [0106] Fig. 2-1 shows the electricity storage device before charging. As shown in Figure 2-1 (B), before charging, the anions and cations were not intercalated or adsorbed on the positive and negative electrodes. In Fig. 2-1 (A), the squares of the positive and negative electrodes are the height of the capacitance, the potential range in the horizontal position is charged, and the area of the square is the integrated capacity of each (integrated electric charge that can be charged by normal charging). The quantity mAH) is schematically represented. The positive electrode capacity is the adsorption capacity. And the sum of the two intercalation capacities.
[0107] 次に、この電池を充電していくと、図 2— 2 (B)に示すように、正極から負極へ電子 が移動し、負極に電子が蓄積され正極に正孔が蓄積される。また負極表面にはカチ オンが吸着され、正極にはァニオンがインターカレーシヨンしている。図 2— 2 (A)に は、正極、負極の容量が部分的に充電された様子を示す。  Next, when this battery is charged, as shown in FIG. 2 (B), electrons move from the positive electrode to the negative electrode, electrons are accumulated in the negative electrode, and holes are accumulated in the positive electrode. . Catonion is adsorbed on the negative electrode surface, and anion is intercalated on the positive electrode. Figure 2-2 (A) shows the state where the positive and negative electrode capacities were partially charged.
[0108] さらに充電を進め、正極側で不可逆反応開始電位 (この例では溶媒の酸化分解電 位）にちようど達した状態、即ち、正極が充電可能な積算容量に達した状態を図 2— 3に示す。図 2— 3 (B)に示すように、正極力、ら負極に N個の電子が流れ、負極には N 個の電子が蓄積されると共に N個の電荷をもつカチオンが吸着し、正極には N個の 正孔が蓄積されると共に、 N個の電荷を持つァニオンがインターカレーシヨンして!/、る 。このとき、図 2— 3 (A)に示すように、正極の積算容量は全部充電されているが、負 極には未だ充電可能な容量が残存して!/、る (図中の「余裕部分」 )。  [0108] Further charging is performed, and the state in which the irreversible reaction start potential (in this example, the oxidative decomposition potential of the solvent) is reached on the positive electrode side, that is, the state in which the positive electrode has reached the chargeable accumulated capacity is shown in FIG. — Shown in 3. As shown in Figure 2-3 (B), N electrons flow to the negative electrode, and the negative electrode accumulates N electrons and adsorbs N charged cations to the positive electrode. As N holes accumulate, anions with N charges intercalate! /. At this time, as shown in Fig. 2-3 (A), the accumulated capacity of the positive electrode is fully charged, but there is still a chargeable capacity remaining on the negative electrode! Part ").
[0109] このような状態は、負極の積算容量が正極の積算容量より大きくなるように設定する ことで、達成できる。正極容量/負極容量比の好ましい範囲は 0. 5〜0. 95である。 容量比が 0. 5未満でも本態様 Bの効果は発現するが、負極が過多になると容量低下 が大きくなるので 0. 5以上が好ましい。容量比が 0. 95以上では遷移電圧のシフトが 少なぐ高電圧化の効果の点で不十分になりがちである。さらに好ましい正極容量/ 負極容量比は 0. 75—0. 9である。  Such a state can be achieved by setting the accumulated capacity of the negative electrode to be larger than the accumulated capacity of the positive electrode. A preferable range of the positive electrode capacity / negative electrode capacity ratio is 0.5 to 0.95. Even if the capacity ratio is less than 0.5, the effect of the present embodiment B is exhibited, but if the number of the negative electrode is excessive, the capacity reduction is increased, so 0.5 or more is preferable. When the capacitance ratio is 0.95 or more, the transition voltage shift tends to be insufficient in terms of the effect of higher voltage. A more preferable positive electrode capacity / negative electrode capacity ratio is 0.75-0.9.
[0110] そこで、使用する溶媒系にも依存するが、正極電位を 5. 2V vs. Li+/Li以上（ 好ましくは 5. 5V以上）、負極電位を 1. 9V vs. Li+/Li以上とし、両極間の電圧 を 3. 4V、好ましくは 3. 5V以上に設定することによって、正極表面で電解液の不可 逆的な分解反応が起きる。そこで、図 2— 4に示すように、仮に両極間の充電電圧を 3 . 5Vとして充電すると、正極容量より負極容量を大きく設計した本態様 Bの蓄電デバ イスでは過充電によって、正極で電解液の酸化分解が起き、正極では n個の正孔が 消費される（n個の電子を吸収する）。このとき負極では等価の n個の電子が貯蔵され [0110] Therefore, the positive electrode potential is 5.2 V vs. Li + / Li or more (preferably 5.5 V or more) and the negative electrode potential is 1.9 V vs. Li + / Li or more, depending on the solvent system used. By setting the voltage between the two electrodes to 3.4 V, preferably 3.5 V or more, an irreversible decomposition reaction of the electrolyte occurs on the surface of the positive electrode. Therefore, as shown in Fig. 2-4, if the charging voltage between the two electrodes is set to 3.5 V, the battery device of this mode B, which is designed to have a negative electrode capacity larger than the positive electrode capacity, is overcharged and the electrolyte solution at the positive electrode. Oxidative decomposition occurs, and n holes are consumed at the positive electrode (n electrons are absorbed). At this time, equivalent n electrons are stored in the negative electrode.
[0111] 図 2— 5では充電された N個の電子が放電された状態を示す。正極には N個の電 子が流入し、正極は電気的に中性で電荷を有さない状態となっている力 負極には n個の電子が貯蔵されている。しかし、この状態では、未だ正極の電位がわずかに高 く、正極と負極の電位がバランスしていない。 [0111] Figure 2-5 shows a state where N charged electrons are discharged. N electrons flow into the positive electrode, and the positive electrode is electrically neutral and has no charge. n electrons are stored. However, in this state, the potential of the positive electrode is still slightly high, and the potentials of the positive electrode and the negative electrode are not balanced.
[0112] さらに負極の電子の一部が正極に流れると、電位がバランスして完全放電状態に なる。この状態を図 2— 6に示す。尚、このとき流れる電子は非常にわずかであるので 、図中では無視している。 n個電子が有する電荷量を Qとすると、 Qは正極と負極の 静電容量に比例して分配され、電位のバランスが図られる。つまり正極の吸着部分の 静電容量を Cc、分配される電圧を Vc、負極の吸着部分の静電容量を Ca、分配さ れる電圧を Vaとすると [0112] Further, when some of the electrons of the negative electrode flow to the positive electrode, the potential is balanced and a complete discharge state occurs. This state is shown in Figure 2-6. In addition, since the electrons flowing at this time are very few, they are ignored in the figure. If the amount of charge of n electrons is Q, Q is distributed in proportion to the positive and negative electrode capacities, and the potential is balanced. In other words, if the electrostatic capacity of the positive electrode adsorption part is Cc, the distributed voltage is Vc, the electrostatic capacity of the negative electrode adsorption part is Ca, and the distributed voltage is Va.
Q = Qa + Qc  Q = Qa + Qc
Va =Vc  Va = Vc
Va = wa / Ca = Qc Zし c =Vc  Va = wa / Ca = Qc Z and c = Vc
が成り立つ条件で電荷と電圧がバランスする。しかしながら、現実には負極活物質と しての活性炭の静電容量は正極活物質としての黒鉛の吸着部分の静電容量に比較 してはるかに大きいので、  The charge and voltage are balanced under the condition that holds. However, in reality, the capacitance of activated carbon as the negative electrode active material is much larger than the capacitance of the adsorption part of graphite as the positive electrode active material.
Q = Qa > > Qc = 0  Q = Qa>> Qc = 0
が成立する。完全に放電した状態すなわち電荷と電圧がバランスした時点では、 n個 の電子のほとんどは、負極側に留まり、わずかの電子が正極に存在する。その結果、 完全放電時に、負極には放出できない負電荷 Qが存在するため、負極の積算容量 は Qだけ減少する。しかし、本態様 Bの構成では、負極の容量を正極に比べて十分 大きく設定しているので、容量の減少は電池全体の容量には影響を与えない。一方 、等電位点は、 Vaだけ低電位側にシフトする。そのため、充電を行うときに、初期より 、 Vaだけ低電位から充電が開始するため、正極のインターカレーシヨン開始電圧（ 遷移電圧 Vt)は、 Vaだけ高くなる。従って、本態様 Bの蓄電デバイスは、高電圧で 充放電が可能になる。  Is established. In a fully discharged state, that is, when the charge and voltage are balanced, most of the n electrons remain on the negative electrode side, and a few electrons are present on the positive electrode. As a result, there is a negative charge Q that cannot be released to the negative electrode during full discharge, so the accumulated capacity of the negative electrode decreases by Q. However, in the configuration of the present aspect B, the capacity of the negative electrode is set to be sufficiently larger than that of the positive electrode, so that the decrease in capacity does not affect the capacity of the entire battery. On the other hand, the equipotential point shifts to the lower potential side by Va. Therefore, when charging is performed, charging starts from a low potential by Va from the beginning, so that the positive intercalation start voltage (transition voltage Vt) increases by Va. Therefore, the electricity storage device of this aspect B can be charged and discharged at a high voltage.
[0113] 本態様 Bでは、過充電を 1回だけ行ってもよいが、複数回行ってもよい。ここでは、 引き続き 2回目の過充電を行う例を説明する。  [0113] In this mode B, overcharging may be performed only once, but may be performed a plurality of times. Here, an example of the second overcharge will be described.
[0114] 2回目の充電では、 1回目の充電と同様の操作を行う。 2回目の過充電においても 不可逆反応が起こるように、正極側で不可逆反応開始電位 (この例では溶媒の酸化 分解電位）を超えるように充電を行う。図 2— 7に示すように、仮に 1回目の過充電と同 じょうに、両極間に充電電圧が 3. 5Vになるまで充電すると、電解液の分解、すなわ ち過充電が開始する。ここで、例えば正極で m個の正孔が電解液の分解に新たに消 費されたとすると (m個の電子の吸収）、負極では m個の電子が蓄えられる。この状態 では、正極に蓄積されている正孔が N個であるのに対して、負極で蓄積されている電 子は N + n + m個である。尚、ここで m = nとなるようにしてもよい。 [0114] In the second charge, the same operation as the first charge is performed. The irreversible reaction initiation potential on the positive electrode side (in this example, the oxidation of the solvent) Charge to exceed the decomposition potential. As shown in Figure 2-7, as with the first overcharge, if the charge voltage is charged between the two electrodes until the charge voltage reaches 3.5 V, the electrolyte will be decomposed, that is, overcharge will begin. Here, for example, if m positive holes are newly consumed for the decomposition of the electrolyte at the positive electrode (absorption of m electrons), m electrons are stored at the negative electrode. In this state, there are N holes accumulated in the positive electrode, whereas N + n + m electrons are accumulated in the negative electrode. Here, m = n may be satisfied.
[0115] そこで、完全放電を行うと、 n + m個の電子が有する電荷 Q +Q 1 正極と負極の [0115] Therefore, when complete discharge is performed, the charge of n + m electrons Q + Q 1 between the positive and negative electrodes
1 2  1 2
静電容量に比例して分配され、電位のバランスが行われる。 1回目の完全放電後と 同様に、 Q +Q =Qa +Qc +Qa +Qc  It is distributed in proportion to the capacitance, and the potential is balanced. Q + Q = Qa + Qc + Qa + Qc as after the first full discharge
1 2 1 1 1 2  1 2 1 1 1 2
Va +Va =Vc +Vc  Va + Va = Vc + Vc
1 2 1 2  1 2 1 2
Va +Va =(Qa +Qa )/Ca=(Qc +Qc )/Cc=Vc +Vc  Va + Va = (Qa + Qa) / Ca = (Qc + Qc) / Cc = Vc + Vc
1 2 1 2 1 2 1 2  1 2 1 2 1 2 1 2
が成り立つ条件で電荷と電圧がバランスする。負極の静電容量が正極の静電容量よ りはるかに大きいので、  The charge and voltage are balanced under the condition that holds. Since the negative electrode capacitance is much larger than the positive electrode capacitance,
Q +Q =Qa +Qa > >Qc +Qc =0  Q + Q = Qa + Qa>> Qc + Qc = 0
1 2 1 2 1 2  1 2 1 2 1 2
が成り立つ。即ち、図 2— 8(B)に示すように、 n + m個の電子のほとんどは負極側に 留まったままで、わずかの電子が正極に流れてバランスする。図 2— 8(A)に示すよう に、この結果、完全放電時に負極に存在する負電荷は、負極の積算容量の減少分と なる。一方、等電位点が Vc +Vcだけ低電位にシフトするために、正極における充  Holds. In other words, as shown in Fig. 2-8 (B), most of the n + m electrons remain on the negative electrode side, and a few electrons flow to the positive electrode and balance. As shown in Figure 2-8 (A), as a result, the negative charge present in the negative electrode at the time of complete discharge is a decrease in the accumulated capacity of the negative electrode. On the other hand, since the equipotential point shifts to a lower potential by Vc + Vc,
1 2  1 2
電過程が吸着からインターカレーシヨンに変わる遷移電圧は、この例では、 Va +Va だけ、高電圧側に変化する。  In this example, the transition voltage at which the electrical process changes from adsorption to intercalation changes to the high voltage side by Va + Va.
2  2
[0116] 本態様 Bの上記処理は開放充電の段階で行うことが好ましぐそして実際の使用時 の充電は電解液が分解しな!/、正極電位、負極電位および端子間電圧に設定する。 図 2— 14に、実際の使用時 (定常状態）における限界充電電位と端子間電圧を示す 。図中の「充電上限界電位」は、溶媒の酸化分解反応が開始する限界の正極電位で ある。充電時の正極電位は、対 Li+/Li基準電位で 5. 2V以下、好ましくは 5.0V以 下である。図中の「充電下限界電位」は、溶媒の還元分解が始まる負極電位または 正極が「充電上限限界電位」に達したときの負極電位のどちらか高い方である。この 図では、両者がちょうど等しい例として、 1. 7Vvs. Li+/Liの例を示した。負極の充 電電位は、 1. 7Vvs. Li+/Li以上が好ましぐ特に 1 · 9Vvs. Li+/Li以上が好まし い。 [0116] It is preferable to perform the above-described treatment of the present embodiment B at the stage of open charge, and the charge during actual use is set so that the electrolyte does not decompose! /, The positive electrode potential, the negative electrode potential, and the inter-terminal voltage. . Figure 2-14 shows the limit charge potential and the terminal voltage during actual use (steady state). “Charge upper limit potential” in the figure is the limit positive electrode potential at which the oxidative decomposition reaction of the solvent starts. The positive electrode potential during charging is 5.2 V or less, preferably 5.0 V or less, with respect to the Li + / Li reference potential. The “lower charging potential” in the figure is the higher of the negative electrode potential at which the reductive decomposition of the solvent begins or the negative electrode potential when the positive electrode reaches the “upper charging limit potential”. In this figure, 1.7 Vvs. Li + / Li is shown as an example where they are exactly equal. Negative electrode charging The electric potential is preferably 1.7 Vvs. Li + / Li or more, particularly preferably 1 · 9 Vvs. Li + / Li or more.
[0117] このような条件から、充電電圧（正極と負極の端子間電圧）として、電解液が分解し ない電圧は 3. 5V以下、好ましくは 3. 4V以下、さらに好ましくは 3. 2V以下である。 この条件で充放電を行うことにより本蓄電デバイスの遷移電圧は 0. 55V力、ら 1. 5V 程度増加する。  [0117] Under these conditions, as the charging voltage (voltage between the positive and negative terminals), the voltage at which the electrolyte does not decompose is 3.5 V or less, preferably 3.4 V or less, more preferably 3.2 V or less. is there. By charging / discharging under this condition, the transition voltage of the electricity storage device increases by about 0.5V, or 1.5V.
[0118] このように、正極側で不可逆反応が起きる電圧で、 1回または複数回の開放充放電 を行うと、遷移電圧が高い蓄電デバイスを得ることができる。遷移電圧が高いことはデ バイスの動作電圧が高ぐ高エネルギーであることを意味する。本態様 Bの処理によ つて負極容量は漸減する力 この容量減少は本態様 Bの蓄電デバイスにおいては 2 Vないし 2. 2V以下の低電圧動作域での容量減少である。したがって実用の高電圧 域での容量には何ら変化はない。つまり 0Vから 1. 75Vないし 2V間の低電圧域で充 放電を行う場合には容量低下が現れる力 例えば 2V以上の高電圧域で充放電を行 う限り、容量変化はない。  [0118] As described above, an electrical storage device having a high transition voltage can be obtained by performing one or more open charge / discharge cycles at a voltage at which an irreversible reaction occurs on the positive electrode side. A high transition voltage means that the operating voltage of the device is high and high energy. The force by which the negative electrode capacity is gradually reduced by the treatment of the present embodiment B This decrease in capacity is a decrease in capacity in a low voltage operation region of 2 V to 2.2 V or less in the storage device of the present embodiment B. Therefore, there is no change in the capacity in the practical high voltage range. In other words, when charging / discharging in the low voltage range from 0V to 1.75V to 2V, the capacity appears to decrease in capacity.
[0119] 以上の説明では、不可逆反応が、溶媒の酸化分解よつて起こる場合を例に挙げた 、溶媒の酸化分解に限られず、過充電によって正極で正孔が消費されるような不 可逆反応 (酸化反応）が起こるような反応が利用できる。即ち、電池性能に悪影響を 与えずに、正極で正孔を消費するような反応であればどのような反応であってもよレ、  [0119] In the above description, the case where the irreversible reaction occurs due to the oxidative decomposition of the solvent has been described as an example. Reactions that cause (oxidation reactions) can be used. In other words, any reaction that consumes holes at the positive electrode without adversely affecting battery performance is acceptable.
[0120] 例えば、過充電時に正極で分解する材料をあらかじめ添加しておいてもよい。開放 充電時に正極で分解する電気容量分を負極で蓄えることができて、その電荷に相当 する電位分だけ遷移電圧を高めることができる。この方法では正極に過多のァニォ ンのインターカレーシヨンが行われないために、サイクル特性の改善に効果がある。 [0120] For example, a material that decomposes at the positive electrode during overcharge may be added in advance. The electric capacity that decomposes at the positive electrode during open charge can be stored at the negative electrode, and the transition voltage can be increased by the potential corresponding to the charge. This method is effective in improving cycle characteristics because no excessive anion intercalation is performed on the positive electrode.
[0121] また、過充電を行う電圧は、不可逆反応が起きる電圧に依存して適宜決められる。  [0121] The voltage for overcharging is appropriately determined depending on the voltage at which the irreversible reaction occurs.
溶媒の酸化分解でも、溶媒によって分解電圧が異なるので、電解液に含まれる溶媒 成分に依存して決めることが好ましレ、。  Even in the oxidative decomposition of the solvent, the decomposition voltage differs depending on the solvent, so it is preferable to determine it depending on the solvent component contained in the electrolyte.
[0122] また、不可逆反応を起こすための過充電を複数回に分ける場合には、 1回での過 充電で必要な容量増大を得る場合に比べ、マイルドな条件を選択することが可能で あるので、一般には 2回以上、好ましくは 5回以上である。また、回数は特に制限され ないが、作業上、例えば 50回以下程度が好ましい。 [0122] In addition, when the overcharge for causing the irreversible reaction is divided into multiple times, it is possible to select milder conditions than when obtaining the required capacity increase with a single overcharge. Therefore, it is generally 2 times or more, preferably 5 times or more. Further, the number of times is not particularly limited, but it is preferably about 50 times or less for work.
[0123] 以上のような過充電および放電は、製品としてデバイスが完成する前の段階におい て、開放状態にて行うことが好ましい。このような工程を経て、製品としての蓄電デバ イスが完成する。 [0123] The overcharge and discharge as described above are preferably performed in an open state before the device is completed as a product. Through these processes, the product electricity storage device is completed.
[0124] 本態様 Bの蓄電デバイスは 3V以上の高電圧でも作動し、高容量で充放電が可能 であることから、高エネルギーを蓄電することが可能である。その用途はパソコンのバ ックアップ電源、携帯電話、携帯用モパイル機器、デジタルカメラの電源などに用い ること力 S可能である。また、本態様 Bの蓄電デバイスは電気自動車や HEVの動力シ ステムにも適用することカできる。  [0124] The electricity storage device of the present aspect B operates even at a high voltage of 3 V or more, and can be charged and discharged with a high capacity, and thus can store high energy. Its use can be used for PC backup power supplies, mobile phones, portable mopile devices, and digital camera power supplies. In addition, the electricity storage device of aspect B can also be applied to electric vehicles and HEV power systems.
[0125] 特に高電圧を必要とする動力系で用いられる場合、本蓄電デバイスの放電電圧は  [0125] In particular, when used in a power system that requires a high voltage, the discharge voltage of the electricity storage device is
1. 5V以上、望ましくは 2V以上でカットすることが好ましい。  1. It is preferable to cut at 5V or higher, preferably 2V or higher.
[0126] また、本態様 Bの蓄電デバイスと、充放電がインターカレーシヨンの領域のみとなる ように、所定電圧まで低下したときにシャットダウンするような、公知の電圧制御手段と を組み合わせて、蓄電システムとすることも好ましい。  [0126] In addition, the power storage device according to the present aspect B is combined with a known voltage control unit that shuts down when the voltage decreases to a predetermined voltage so that charging / discharging is performed only in the intercalation region. A system is also preferable.
[0127] さらに、本態様 Bの蓄電デバイスが、使用時の充電時に、正極電位および負極電 位が前述の範囲になるように、端子間電圧を所定の電圧範囲に制限するように、公 知の電圧制御手段とを組み合わせて、蓄電システムとすることも好まし!/、。  [0127] Further, the electricity storage device of the present aspect B is publicly known to limit the inter-terminal voltage to a predetermined voltage range so that the positive electrode potential and the negative electrode potential are in the above-mentioned range during charging during use. It is also preferable to combine with other voltage control means to make a power storage system! /.
[0128] <各材料の説明〉  [0128] <Description of each material>
次に、本発明（態様 Aおよび態様 B)の蓄電デバイスに使用される具体的材料等を 説明する。本発明の蓄電デバイスには、正極活物質、負極活物質、バインダー、導 電材、集電体、セパレータ、および電解液などの材料が使用される。蓄電デバイスの 形状としては捲回式、スタック式、葛折などが挙げられる。また、電気容量取り出しの システムとしては EcaSS (商標）などの従来の技術をいずれも好適に転用することが できる。  Next, specific materials used for the electricity storage device of the present invention (Aspect A and Aspect B) will be described. For the electricity storage device of the present invention, materials such as a positive electrode active material, a negative electrode active material, a binder, a conductive material, a current collector, a separator, and an electrolytic solution are used. Examples of the shape of the electricity storage device include a winding type, a stack type, and a twist. Moreover, any conventional technology such as EcaSS (trademark) can be suitably used as a system for extracting electric capacity.
[0129] 本出願において、黒鉛とは、炭素原子が SP2混成軌道による六角網平面を構成し ており、この 2次元格子構造が規則的に積層したものを基本構造単位 (結晶子）にし ているものをいい、強い異方性を持っている。黒鉛質材料とは、黒鉛質が十分に発 達しており一般に「黒鉛」として認識される範囲の材料であり、本出願においては、黒 鉛を含む。 [0129] In the present application, graphite means a hexagonal network plane with SP2 hybrid orbital carbon atoms, and this two-dimensional lattice structure is regularly stacked as a basic structural unit (crystallite). Good thing, has strong anisotropy. Graphite material means that graphite is sufficiently generated. In the present application, black lead is included.
[0130] 本発明では、正極および負極の両方に炭素材料を活物質として使用する。正極の 活物質として、黒鉛質材料が挙げられる。正極活物質として用いられる黒鉛質材料 は、天然黒鉛、人造黒鉛いずれでもよぐより高容量を得ようとした場合、高結晶質の 黒鉛を用いることが好ましい。良好なインターカレーシヨンを実現するためには黒鉛 質材料の層間距離が 0. 3357nm以下が好ましぐより好ましくは 0. 3355nm以下で ある。  [0130] In the present invention, a carbon material is used as an active material for both the positive electrode and the negative electrode. Examples of the active material for the positive electrode include graphite materials. The graphite material used as the positive electrode active material may be either natural graphite or artificial graphite. When obtaining a higher capacity, it is preferable to use highly crystalline graphite. In order to achieve good intercalation, the interlayer distance of the graphite material is preferably 0.3357 nm or less, more preferably 0.3355 nm or less.
[0131] または黒鉛質材料の結晶構造には、六方晶構造 (ΑΒΑΒ · ·積層周期）と菱面体構 造 (ABCABC "積層周期）がある。多くの場合、菱面体構造は粉砕によって導入さ れるカ S、インターカレーシヨンによる高容量を得るためには、菱面体構造を有さない 黒鉛であることが好ましい。  [0131] Or the crystal structure of graphite material includes hexagonal structure (晶 ··· stacking period) and rhombohedral structure (ABCABC “stacking period). In many cases, rhombohedral structure is introduced by grinding. In order to obtain a high capacity by potassium S or intercalation, graphite having no rhombohedral structure is preferable.
[0132] また、インターカレーシヨンを急速に行うためには黒鉛質材料の粒子の外表面積は 大きレ、ほど好ましレ、（即ち、黒鉛粒子は小さレ、ほど好ましレ、）力 粉砕時に菱面体構 造が導入され、黒鉛質材料の結晶性が損なわれることが多い。したがって好ましい黒 鉛質材料の平均粒子径は 3〜40 mであり、さらに好ましくは 6〜25 mである。  [0132] Further, in order to rapidly perform the intercalation, the outer surface area of the graphite material particles is preferably larger, that is, the more preferable (that is, the smaller the graphite particles, the more preferable it is). The rhombohedral structure is often introduced, and the crystallinity of the graphite material is often impaired. Therefore, the average particle diameter of the preferable black lead material is 3 to 40 m, and more preferably 6 to 25 m.
[0133] 黒鉛質材料の比表面積については、例えばジェットミル等を用いて、菱面体構造が 導入されな!/、ようにして黒鉛質材料の結晶性を維持したままで粉砕すると、比表面積 ；!〜 20m2/gに調整することが可能である力 S、正極表面での溶媒の分解速度を下げ るためには 10m2/g以下、更に好ましくは 2〜5m2/gであることが好ましい。 [0133] Regarding the specific surface area of the graphite material, for example, when a rhombohedral structure is not introduced using a jet mill or the like, and the powder is pulverized while maintaining the crystallinity of the graphite material, the specific surface area; ! ~ 20m 2 / g can be adjusted to S, 10m 2 / g or less, more preferably 2 to 5m 2 / g in order to lower the decomposition rate of the solvent on the positive electrode surface. preferable.
[0134] さらに、蓄電デバイスの単位体積当たりの蓄電容量を増加させるためには黒鉛質 材料を圧密化処理したり、黒鉛質材料から微細粒子を除去したりすることも有効であ る。圧密化処理された黒鉛のタップ密度は 0· 8〜； ! · 4g/cc、真密度は 2· 22g/cc 以上が好ましい。また実質的に 1 μ m以下の黒鉛質材料の割合を 10%以下とするこ とによっても黒鉛の嵩密度の低下が抑制されかつ表面積の増大が抑制される。  [0134] Further, in order to increase the power storage capacity per unit volume of the power storage device, it is also effective to consolidate the graphite material or to remove fine particles from the graphite material. It is preferable that the tap density of the consolidated graphite is 0 · 8˜;! · 4 g / cc, and the true density is 2.2 · 22 g / cc or more. In addition, when the ratio of the graphite material of 1 μm or less is substantially 10% or less, the decrease in the bulk density of the graphite is suppressed and the increase in the surface area is also suppressed.
[0135] 負極の活物質として使用される炭素系材料としては、充放電の際にイオンの吸着の み、即ちインターカレーシヨンが生じないような材料が選ばれることが好ましぐ活性 炭または黒鉛質材料が挙げられる。正極の活物質材料より、比表面積の大きな材料 が好ましい。黒鉛質材料を使用する場合には、正極の活物質の材料と異なるものが 好ましぐ特に正極に使用される黒鉛質材料より比表面積の大きなものが選ばれる。 活性炭としては、公知のキャパシタ用活性炭を使用することができる。例えば薬品賦 活した椰子殻活性炭をはじめ、水蒸気賦活した椰子殻活性炭、フエノール樹脂活性 炭およびピッチ活性炭、またはアルカリ賦活したフエノール樹脂活性炭およびメソフエ ースピッチ活性炭を用いることができる。通常の活性炭のほかに、高表面積化した黒 鉛質材料、 CVD処理した活性炭または黒鉛質材料等を用いることもできる。負極の 活物質として使用される炭素系材料は、比表面積が 300m2/g以上であることが好 ましぐ特に 450m2/g〜2000m2/gの高表面積を有することが好ましい。通常は、 負極活物質として活性炭を使用することが好ましいが、容積あたりの蓄電容量の高密 度化を求める場合には、高表面積黒鉛質材料は圧密化して嵩密度を高めることがで きるので好適である。 [0135] As the carbon-based material used as the negative electrode active material, it is preferable to select a material that only adsorbs ions during charging and discharging, that is, a material that does not generate intercalation. Quality materials. Material with a larger specific surface area than the active material of the positive electrode Is preferred. When using a graphite material, a material different from the material of the active material of the positive electrode is preferred, and a material having a specific surface area larger than that of the graphite material used for the positive electrode is selected. As the activated carbon, known activated carbon for capacitors can be used. For example, chemical activated coconut shell activated carbon, steam activated coconut shell activated carbon, phenol resin activated carbon and pitch activated carbon, or alkali activated phenol resin activated carbon and mesophase pitch activated carbon can be used. In addition to normal activated carbon, high surface area black lead material, CVD-treated activated carbon or graphite material can also be used. Carbonaceous material used as the active material of the negative electrode, the specific surface area is 300 meters 2 / g or more preferably has a high surface area of good Mashigu particularly 450m 2 / g~2000m 2 / g. Normally, it is preferable to use activated carbon as the negative electrode active material, but when high density storage capacity per volume is desired, high surface area graphite material can be compacted to increase bulk density, which is preferable. It is.
[0136] バインダーについても特に限定はなぐ PVDF、 PTFE、ポリエチレンおよびゴム系 のバインダー等を用いることができる。  [0136] The binder is not particularly limited, and PVDF, PTFE, polyethylene, rubber-based binders, and the like can be used.
[0137] 例えばゴム系のバインダー成分としては、 EPT、 EPDM,ブチルゴム、プロピレンゴ ム、天然ゴムなどの脂肪族に代表されるゴム、またはスチレンブタジエンゴム等の芳 香族ゴムを含有したゴムが挙げられる。これらのゴムの構造には二トリル、アクリル、力 ルポニル等のへテロ含有基質またはシリコンを含んでいても良ぐさらには直鎖や分 枝を制限するものではない。なおこれらを単独または複数の混合で用いても良好な バインダーとなり得る。  [0137] For example, rubber-based binder components include rubbers typified by aliphatics such as EPT, EPDM, butyl rubber, propylene rubber and natural rubber, or rubbers containing aromatic rubbers such as styrene butadiene rubber. It is done. The structure of these rubbers may contain a hetero-containing substrate such as nitrile, acrylic, force sulfonyl, or silicon, and is not limited to straight chain or branching. In addition, even if these are used individually or in mixture of several, it can become a favorable binder.
[0138] また、必要に応じてカーボンブラック、ケッチェンブラック等の導電材を添加してもよ い。  [0138] Further, if necessary, a conductive material such as carbon black or ketjen black may be added.
[0139] 集電体としては一般に純アルミ箔が用いられる力 純アルミであっても銅、マンガン 、シリコン、マグネシウム、亜鉛などの金属を単独または複数添加したアルミニウムで あっても良い。またステンレス、ニッケノレ、チタンなどでも同様に用いられる。また導電 性の増幅と強度確保のために上記混合物やその他の元素を添加したものでも使用 できる。この時これらの基質の表面にエッチングなどで凹凸を付与したり、導電性の 金属やカーボンを基質に埋め込む力、、またはコートしても良い。これらの集電体は箔 でもメッシュ状でも用いられる。 [0139] As a current collector, pure aluminum foil is generally used. Pure aluminum foil or aluminum containing a single metal or a plurality of metals such as copper, manganese, silicon, magnesium, and zinc may be used. Also, stainless steel, nickel cane, titanium, etc. are used similarly. In addition, in order to increase conductivity and secure strength, those added with the above mixture and other elements can also be used. At this time, the surface of these substrates may be roughened by etching or the like, or a conductive metal or carbon may be embedded in the substrate, or may be coated. These current collectors are foil But it can also be used in mesh form.
[0140] セパレータとしてセルロース紙、ガラス繊維紙のほかに、ポリエチレンテレフタレート 、ポリエチレン、ポリプロピレン、ポリイミド微多孔膜やそれらが層状に構成された多層 膜が用いられる。またこれらのセパレータ表面に PVDFやシリコン樹脂、ゴム系樹脂 などをコーティングすることでも代用可能であるし、酸化アルミニウム、二酸化珪素、 酸化マグネシウムなどの金属酸化物の粒子が埋包してあっても良い。もちろんこれら のセパレータは正負極間に一枚であってもそれ以上あっても問題なぐ 2種類以上の セパレータを任意に選択して使用しても良い。  [0140] As the separator, in addition to cellulose paper and glass fiber paper, polyethylene terephthalate, polyethylene, polypropylene, polyimide microporous film and a multilayer film composed of these layers are used. Alternatively, PVDF, silicon resin, rubber resin, etc. can be coated on the surface of these separators, or metal oxide particles such as aluminum oxide, silicon dioxide, and magnesium oxide may be embedded. . Of course, these separators may be used by arbitrarily selecting two or more types of separators that do not matter even if there is one or more between the positive and negative electrodes.
[0141] 電解液として用いる有機溶媒は、プロピレンカーボネート等の環状炭酸エステル、 γ プチ口ラタトンなどの環状エステル、 Ν メチルピロリドンなどの複素環状化合物 、ァセトニトリルなどの二トリル類、その他スルホランやスルホキシド等の極性溶媒が利 用出来る。  [0141] Organic solvents used as the electrolyte include cyclic carbonates such as propylene carbonate, cyclic esters such as γ-petit-lataton, 複 素 heterocyclic compounds such as methylpyrrolidone, nitriles such as acetonitrile, and other sulfolanes and sulfoxides. Polar solvent can be used.
[0142] 具体的には以下の化合物である。  [0142] Specifically, the following compounds are included.
エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、 γ—ブチロラ タトン、 δ バレロラタトン、 Ν メチルピロリドン、 Ν, Ν ジメチルイミダゾリジノン、 Ν メチルォキサゾリジノン、ァセトニトリル、メトキシァセトニトリル、 3—メトキシプロピオ 二トリル、グルタロニトリル、アジポニトリル、スルホラン、 3—メチルスルホラン、ジメチ ルスルホキシド、 Ν, Ν ジメチルホルムアミド、リン酸トリメチル。  Ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolatathone, δ valerolatatone, Ν methylpyrrolidone, Ν, ジ メ チ ル dimethylimidazolidinone, メ チ ル methyloxazolidinone, acetonitrile, methoxyacetonitrile, 3-methoxypropionitrile , Glutaronitrile, adiponitrile, sulfolane, 3-methylsulfolane, dimethyl sulfoxide, Ν, ジ メ チ ル dimethylformamide, trimethyl phosphate.
これらの溶媒は単独であっても 2種類以上の混合であっても使用出来る。  These solvents can be used alone or in combination of two or more.
[0143] 非水電解液中に含有される電解質としては、アンモニゥム塩、ピリジニゥム塩、ピロリ ジニゥム塩、ピペリジニゥム塩、イミダゾリウム塩、ホスホニゥム塩などのォニゥム塩が 好ましぐこれらの塩のァニオンとしてはホウフッ化物イオン（BF―)、へキサフルォロ [0143] As the electrolyte contained in the non-aqueous electrolyte, ammonium salts such as ammonium salt, pyridinium salt, pyrrolidinium salt, piperidinium salt, imidazolium salt, and phosphonium salt are preferred as anions of these salts. Boron fluoride ion (BF-), hexafluoro
4  Four
リン酸イオン (PF―)、トリフルォロメタンスルホン酸イオン等のフッ素化合物が好まし  Fluorine compounds such as phosphate ion (PF-) and trifluoromethanesulfonate ion are preferred.
6  6
い。  Yes.
[0144] 具体的には以下の化合物である。 ッ化ジェチルジメチルアンモニゥム、ホウフッ化トリェチルメチルアンモニゥム、ホウフ ブチルメチルアンモニゥム、ホウフッ化テトラブチルアンモニゥム、ホウフッ化テトラへ キシルアンモニゥム、ホウフッ化プロピルトリメチルアンモニゥム、ホウフッ化ブチルトリ メチルアンモニゥム、ホウフッ化へプチルトリメチルアンモニゥム、ホウフッ化（4 ペン テュル）トリメチルアンモニゥム、ホウフッ化テトラデシルトリメチルアンモニゥム、ホウフ ッ化へキサデシルトリメチルアンモニゥム、ホウフッ化へプタデシルトリメチルアンモニ ゥム、ホウフッ化ォクタデシルトリメチルアンモニゥム、 1 , 1，ージフルオロー 2, 2，ービ ピリジニゥム ビステトラフルォロボレート、ホウフッ化 N, N ジメチルピロリジニゥム、 ホウフッ化 N ェチルー N メチルピロリジニゥム、ホウフッ化 N, N ジェチルピロリ ジニゥム、ホウフッ化 N, N ジメチルビペリジニゥム、ホウフッ化 N ェチル N メ チルピペリジニゥム、ホウフッ化 N, N ジェチルビペリジニゥム、ホウフッ化 1 , 1ーテ トラメチレンピロリジニゥム、ホウフッ化 1 , 1 ペンタメチレンピペリジニゥム、ホウフッ 化 N ェチルー N メチルモルフオリ二ゥム、ホウフッ化アンモニゥム、ホウフッ化テト ホスホニゥム、ホウフッ化テトラブチルホスホニゥム、へキサフルォロリン酸テトラメチル アンモニゥム、へキサフルォロリン酸ェチルトリメチルアンモニゥム、へキサフルォロリ ン酸テトラェチルアンモニゥム、へキサフルォロリン酸ビュルトリメチルアンモニゥム、 へキサフルォロリン酸へキサデシルトリメチルアンモニゥム、へキサフルォロリン酸ドデ シルトリメチルアンモニゥム、過塩素酸テトラエチルアンモニゥム、へキサフルォロヒ酸 テトラエチルアンモニゥム、へキサフルォロアンチモン酸テトラェチルアンモニゥム、ト リフルォロメタンスルホン酸テトラェチルアンモニゥム、ノナフルォロブタンスルホン酸 テトラエチルアンモニゥム、ビス（トリフルォロメタンスルホニル）イミドテトラェチルアン モニゥム、トリェチルメチルホウ酸テトラェチルアンモニゥム、テトラエチルホウ酸テトラ ェチルアンモニゥム、テトラブチルホウ酸テトラェチルアンモニゥム、テトラフエニルホ ゥ酸テトラェチルアンモニゥム、へキサフルォロリン酸 1ーェチルー 3—メチルイミダゾ リウム、ホウフッ化 1ーェチルー 3—メチルイミダゾリゥム、トリフルォロメタンスルホン酸 1 ェチル 3ーメチルイミダゾリゥム、へキサフルォロリン酸 1ーブチルー 3—メチル イミダゾリゥム、ホウフッ化 1—ブチル 3—メチルイミダゾリゥム、トリフルォロメタンス ルホン酸 1 ブチル 3—メチルイミダゾリゥム、へキサフルォロリン酸 1 へキシル 3—メチルイミダゾリゥム、ホウフッ化 1一へキシルー 3—メチルイミダゾリゥム、トリフル ォロメタンスルホン酸 1一へキシルー 3—メチルイミダゾリゥム、へキサフルォロリン酸 1 ーォクチルー 3—メチルイミダゾリゥム、ホウフッ化 1ーォクチルー 3—メチルイミダゾリ ゥム、ホウフッ化 1ーブチルー 2, 3 ジメチルイミダゾリゥム、トリフルォロメタンスルホ ン酸 1ーブチルー 2, 3 ジメチルイミダゾリゥム、ホウフッ化 1一へキシルー 2, 3 ジ メチルイミダゾリゥム、トリフルォロメタンスルホン酸 1一へキシルー 2, 3 ジメチルイミ ダゾリゥム、へキサフルォロリン酸 1—ブチルピリジニゥム、ホウフッ化 1—ブチルピリジ 二ゥム、トリフルォロメタンスルホン酸 1 ブチルピリジニゥム、へキサフルォロリン酸 1 一へキシルピリジニゥム、ホウフッ化 1一へキシルピリジニゥム、トリフルォロメタンスル ホン酸 1一へキシルピリジニゥム、へキサフルォロリン酸 1ーブチルー 4 メチルピリジ 二ゥム、ホウフッ化 1ーブチルー 4 メチルピリジニゥム、 1 フルォロピリジニゥムピリ ジン ヘプタフルォロジボレート、ホウフッ化 1 フルォロピリジニゥム。 [0144] Specifically, the following compounds are included. Jetyldimethylammonium fluoride, triethylmethylammonium borofluoride, Hof Butylmethyl ammonium, borofluoride tetrabutyl ammonium, borofluoride tetrahexyl ammonium, borofluoride propyltrimethylammonium, borofluoride butyltrimethylammonium, borofluoride heptyltrimethylammonium, borofluoride (4 pentyl) trimethylammonium, tetradecyltrimethylammonium borofluoride, hexadecyltrimethylammonium borofluoride, heptadecyltrimethylammonium borofluoride, octadecyltrimethylammonium borofluoride, 1,1, -difluoro-2,2-bipyridinium bistetrafluoroborate, borofluoride N, N dimethylpyrrolidinium, borofluoride N ethylol-N methylpyrrolidinium, borofluoride N, N jetylpyrroline nium, borofluoride N, N Dimethylbiperidinium, borofluoride N ethyl N methylpiperidinium, borofluoride N, N Jetylbiperidinium, borofluoride 1,1-Tetramethylenepyrrolidinium, borofluoride 1,1 penta Methylenepiperidinium, borofluoride N ethylol N methyl morpholinum, borofluoride ammonium, borofluoride tetophosphonium, tetrabutylphosphonium borofluoride, tetramethylammonium hexafluorophosphate, ethyltrimethylammonium hexafluorophosphate Hexafluorophosphate tetraethylammonium, hexafluorophosphate butyltrimethylammonium, hexafluorophosphate hexadecyltrimethylammonium, hexafluorophosphate dodecyltrimethylammonium, tetraethylammonium perchlorate Mu Hexafluoroarsenic acid Tetraethylammonium, Hexafluoroantimonate Tetraethylammonium, Trifluoromethanesulfonate Tetraethylammonium, Nonafluorobutanesulfonate Tetraethylammonium, Bis Chloromethanesulfonyl) imidotetraethylammonium, tetraethylammonium triethylmethylborate, tetraethylammonium tetraethylborate, tetraethylammonium tetrabutylborate, tetraethyltetraphenylborate Ammonium, hexafluorophosphate 1-ethyl-3-methylimidazolium, borofluoride 1-ethyl-3-methylimidazolium, trifluoromethanesulfonate 1-ethyl 3-methylimidazolium, hexafluorophosphate 1-butyl-3-methyl Midazoriumu, borofluoride 1-butyl 3-methyl-imidazo Riu arm, triflumizole Ruo Lome chest sulfonic acid 1-butyl 3-methyl-imidazo Riu arm to, to Kisafuruororin acid 1-hexyl 3-Methylimidazolium, borofluoride 1-hexyl chloride 3-Methylimidazolium, trifluoromethanesulfonic acid 1-hexylol 3-Methylimidazolium, hexafluorophosphate 1-octylru 3-methylimidazolium, borofluoride 1-octyl 3-methylimidazole, borofluoride 1-butyl-2,3 dimethylimidazole, trifluoromethanesulfonate 1-butyl-2,3 dimethylimidazole, borofluoride 1 monohexyl 2,3 dimethylimidazole Lithium, trifluoromethanesulfonic acid 1 Monohexyl 2, 3 Dimethylimidazole, Hexafluorophosphoric acid 1-Butylpyridinium, Boron fluoride 1-Butylpyridinium, Trifluoromethanesulfonic acid 1 Butylpyridinium, Hexafluorophosphoric acid 1 monohexylpyridinium, boro 1 Hexylpyridinium, trifluoromethanesulfonic acid 1 Hexylpyridinium, Hexafluorophosphate 1-Butyl-4 Methylpyridinium, Borofluoride 1-Butyl-4 Methylpyridinium, 1 Full Olopyridinum piridine heptafluorodiborate, borofluoride 1 fluoropyridinum.
これらの電解質は単独であっても 2種類以上の混合であっても使用出来る。  These electrolytes can be used alone or in combination of two or more.
実施例  Example
[0145] 以下に本発明の実施例を、態様 Aと態様 Bに分けて説明する。以下に示す実施例 は例示であって、これらに限定されるものではない。  [0145] Examples of the present invention will be described below separately for Aspect A and Aspect B. The following examples are illustrative and are not intended to be limiting.
[0146] 〔態様 Aの実施例〕 [Example of embodiment A]
<実施例 A— 1〉  <Example A-1>
正極活物質として TIMCAL社製黒鉛ティムレックス KS6 (002層間距離 0. 3357η m、平均粒子径 3. 4 111、表面積 20m2/g) 84部に対し電気化学社製アセチレンブ ラック 8部を粉体混合後、呉羽化学社製 PVDF8部の NMP溶液でスラリーを調製し、 アルミ箔上に厚み 140 mの電極を調製した。負極活物質としてクラレケミカル社製 活性炭 RP— 20、平均粒子径 2 111、表面積 1800m2/gの 84部に対しアセチレン ブラック 8部を粉体混合後、 PVDF8部の NMP溶液でスラリーを調製し、アルミ箔上 に厚み 100 H mの負極を調製した。 TIMCAL Ltd. Graphite Tim Rex KS6 as a positive electrode active material (002 interlayer distance 0. 3357η m, an average particle diameter of 3.4 111, surface area of 20 m 2 / g) Powder electrochemical Co. acetylene Bed rack 8 parts per 84 parts After mixing, a slurry was prepared with an NMP solution of 8 parts of PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode having a thickness of 140 m was prepared on an aluminum foil. As a negative electrode active material, Kuraray Chemical Co., Ltd. activated carbon RP-20, average particle size 2 111, surface area 1800m 2 / g 84 parts of acetylene black is mixed with powder, then PVDF 8 parts NMP solution to prepare slurry, A negative electrode having a thickness of 100 Hm was prepared on an aluminum foil.
[0147] 正極活物質重量/負極活物質重量の重量比を 1. 25/1とし、セパレータにガラス 繊維、電解液に 1. 5M/リットル TEMABFの PC溶液を用い、電極面積 3. 14cm2 [0147] The weight ratio of positive electrode active material weight / negative electrode active material weight was 1.25 / 1, glass fiber was used for the separator, and 1.5 M / liter TEMABF PC solution was used for the electrolyte, and the electrode area was 3. 14 cm 2
4  Four
の組立式セルを組み立てた。このセル発生するガスがテフロン絶縁スリーブの隙間か ら放出される仕組みになっている。最初に 1mAで 3. 2Vまで CC充電（定電流充電） を行い、 3. 2Vで 10分間 CV充電（定電圧充電）を行った。その後、 1mAで 0Vまで C C放電したときの放電容量は 37. 6mAh/g (正極活物質重量ベース）であった。 Assembling type cell was assembled. The gas generated in this cell is a gap in the Teflon insulation sleeve. Is released. First, CC charge (constant current charge) was performed to 3.2V at 1mA, and CV charge (constant voltage charge) was performed at 3.2V for 10 minutes. After that, the discharge capacity when CC discharge to 0 V at 1 mA was 37.6 mAh / g (based on the weight of the positive electrode active material).
[0148] 次に開放充電として 3. 5Vまで CC充電を行い、 3. 5Vで 10分間 CV充電を行った 。その後、 1mAで 0Vまで CC放電を行う操作を 10サイクル行った。開放充電時の 1 〜； 10サイクルまでの充放電曲線を電圧変化量を基準に変換した dQ/dV曲線で図 1 9に示す。図 1 9より容量がサイクルごとに増加し、かつ遷移電圧が低下する状 況が読み取れる。 3. 5Vで 10サイクルの開放充電後、充電電圧を 3. 2Vに変更して 充放電試験を行った。 3. 2V充電後の放電容量は 48. 4mAh/g (正極活物質重量 ベース）であり、本態様の開放充電処理によって 28. 7%の容量増加があった。  [0148] Next, CC charging was performed up to 3.5V as an open charge, and CV charging was performed at 3.5V for 10 minutes. After that, 10 cycles of CC discharge to 0V at 1mA were performed. Fig. 19 shows a dQ / dV curve obtained by converting the charge / discharge curve up to 10 cycles at the time of open charge based on the voltage change. From Fig. 19, it can be seen that the capacity increases with each cycle and the transition voltage decreases. 3. After 10 cycles of open charge at 5V, the charge voltage was changed to 3.2V and a charge / discharge test was conducted. 3. The discharge capacity after 2V charge was 48.4 mAh / g (based on the weight of the positive electrode active material), and the capacity increased by 28.7% by the open charge treatment of this embodiment.
[0149] <比較例 A— 1〉  [0149] <Comparative Example A-1>
正極及び負極活物質としてクラレケミカル社製活性炭 RP— 20、平均粒子径 2 m 、表面積 1800m2/gの 84部に対しアセチレンブラック 8部を粉体混合後、 PVDF8 部の NMP溶液でスラリーを調製し、ァノレミ箔上に厚み 150 a mの正極と 100 μ の 負極を調製した。実施例 Α— 1と同様に正極活物質重量/負極活物質重量の重量 比 = 1. 5/1に調製し、実施例 A—1と同様に組立式セルを組み立てた。 1mAで 2. 3Vまで CC充電を行い、 2. 3Vで 10分間 CV充電を行った。 Activated carbon RP-20 (Kuraray Chemical Co., Ltd.) with a mean particle size of 2 m and a surface area of 1800 m 2 / g as a positive and negative electrode active material. After mixing 8 parts of acetylene black with powder, prepare a slurry with 8 parts of PVDF and NMP solution. Then, a positive electrode having a thickness of 150 am and a negative electrode having a thickness of 100 μm were prepared on an anoremi foil. In the same manner as in Example IV-1, the weight ratio of positive electrode active material weight / negative electrode active material weight was adjusted to 1.5 / 1, and an assembly type cell was assembled in the same manner as in Example A-1. CC charge to 2.3V at 1mA and CV charge at 2.3V for 10 minutes.
[0150] その後、 1mAで 0Vまで CC放電を行った初回放電容量は 25. 8mAh/g (正極活 物質重量ベース）であり、電圧を 2. 6Vとした以外実施例 A—1と同様に 10サイクル 開放充電させた。その後、再び 1mAで 2. 3Vまで CC充電を行い、 2. 3Vで 10分間 CV充電を行った。その後、 1mAで 0Vまで CC放電を行った放電容量は 23. OmAh /g (正極活物質重量ベース）であり、開放充電による容量増加は認められなかった  [0150] After that, the initial discharge capacity after CC discharge to 1 V at 0 mA was 25.8 mAh / g (based on the weight of the positive electrode active material), and the same as Example A-1 except that the voltage was 2.6 V. 10 Cycle open charge. After that, CC charge to 2.3V was performed again at 1mA, and CV charge was performed at 2.3V for 10 minutes. After that, the discharge capacity after CC discharge to 0V at 1mA was 23. OmAh / g (based on the weight of positive electrode active material), and no increase in capacity due to open charge was observed.
[0151] <実施例 A— 2〉 [0151] <Example A-2>
正極活物質として TIMCAL社製黒鉛ティムレックス SFG44 (002層間距離 0. 335 4nm、平均粒子径 23. 8 m、表面積 5m2/g) 84部に対し電気化学社製ァセチレ ンブラック 8部を粉体混合後、呉羽化学社製 PVDF8部の NMP溶液でスラリーを調 製し、アルミ箔上に厚み 140 mの電極を調製した。負極活物質としてクラレケミカル 社製活性炭 RP— 20、平均粒子径 2 111、表面積 1800m2/gの 84部に対しァセチ レンブラック 8部を粉体混合後、 PVDF8部の NMP溶液でスラリーを調製し、アルミ 箔上に厚み 100 a mの負極を調製した。 Graphite Timrex SFG44 manufactured by TIMCAL as positive electrode active material (002 interlayer distance 0.335 4 nm, average particle diameter 23.8 m, surface area 5 m 2 / g) 8 parts of acetylene black manufactured by Electrochemical Co., Ltd. as powder After mixing, a slurry was prepared with an NMP solution of 8 parts of PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode having a thickness of 140 m was prepared on an aluminum foil. Kuraray Chemical as negative electrode active material After mixing 8 parts of acetylene black with 84 parts of activated carbon RP-20, average particle size 2 111, surface area 1800m 2 / g, a slurry was prepared with NMP solution of 8 parts of PVDF, and the thickness on the aluminum foil A 100 am negative electrode was prepared.
[0152] 正極活物質重量/負極活物質重量の重量比を 1. 2/1とし、セパレータにガラス 繊維、電解液に 1. 5M/リットル TEMABFの PC溶液を用い、電極面積 3. 14cm2 [0152] The weight ratio of positive electrode active material weight / negative electrode active material weight is 1.2 / 1, glass fiber is used for the separator, and 1.5 M / liter TEMABF PC solution is used for the electrolyte, and the electrode area is 3. 14 cm 2
4  Four
の組立式セルを組み立てた。このセル発生するガスがテフロン絶縁スリーブの隙間か ら放出される仕組みになっている。 1サイクル目と 2サイクル目は 1mAで 3· 2Vまで C C充電を行い、 3. 2Vで 10分間 CV充電を行った。その後、 1mAで 0Vまで CC放電 した。 2サイクル目の放電容量は 41. 6mAh/g (正極活物質重量ベース）であった。  Assembling type cell was assembled. The gas generated in this cell is released from the gap between the Teflon insulation sleeves. In the 1st and 2nd cycles, CC charge was performed at 1mA to 3.2V, and 3.2V was charged for 10 minutes. After that, CC was discharged to 0V at 1mA. The discharge capacity in the second cycle was 41.6 mAh / g (based on the weight of the positive electrode active material).
[0153] 3サイクル目から 13サイクル目まで開放充電として 3. 5Vまで CC充電を行い、 3. 5 Vで 10分間 CV充電を行い、その後 1mAで 0Vまで CC放電を行う操作を行った。 14 サイクル目力も再び 1mAで 3. 2Vまで CC充電を行い、 3. 2Vで 10分間 CV充電を 行い、その後、 1mAで 0Vまで CC放電した。 14サイクル目の放電容量は 54. 5mAh /g (正極活物質重量ベース）であった。 2サイクル目と 14サイクル目の充放電曲線を 電圧変化量を基準に変換した dQ/dV曲線で図 1 13に示す。図 1 13より本態様 Aの処理により遷移電圧が低電圧にシフトし、かつ容量が 31 %増加していることがわ かる。 [0153] From the 3rd cycle to the 13th cycle, CC charging was performed to 3.5V as an open charge, CV charging was performed for 10 minutes at 3.5V, and then CC discharging was performed to 0V at 1mA. The 14th cycle was again charged with CC at 1mA to 3.2V, charged with 3.2V for 10 minutes, and then discharged at 1mA to 0V. The discharge capacity at the 14th cycle was 54.5 mAh / g (based on the weight of the positive electrode active material). Figure 113 shows the dQ / dV curves obtained by converting the charge and discharge curves of the second and 14th cycles based on the voltage change. From Fig. 113, it can be seen that the transition voltage is shifted to a lower voltage and the capacity is increased by 31% by the processing of the present embodiment A.
[0154] 〔態様 Bの実施例〕  [Example of embodiment B]
<実施例 B— 1〉  <Example B-1>
正極活物質として TIMCAL社製黒鉛ティムレックス SFG44 (002層間距離 0. 335 5nm、平均粒子径 23. 8 m、表面積 5. Om2/g) 84部に対し電気化学社製ァセチ レンブラック 8部を粉体混合後、呉羽化学社製 PVDF8部の NMP溶液でスラリーを 調製し、アルミ箔上に電極を調製した。負極活物質としてクラレケミカル社製活性炭 R P— 20、平均粒子径 2 111、表面積 1800m2/gの 84部に対しアセチレンブラック 8 部を粉体混合後、 PVDF8部の NMP溶液でスラリーを調製し、アルミ箔上に負極を 調製した。 As positive electrode active material, TIMCAL graphite Timrex SFG44 (002 interlayer distance 0.335 nm, average particle diameter 23.8 m, surface area 5. Om 2 / g) 84 parts by Electrochemical Acetylene Black 8 parts After powder mixing, slurry was prepared with NMP solution of 8 parts PVDF manufactured by Kureha Chemical Co., Ltd., and an electrode was prepared on aluminum foil. As a negative electrode active material, 8 parts of acetylene black was mixed with 84 parts of activated carbon RP-20, Kuraray Chemical Co., Ltd., average particle size 2 111, surface area 1800 m 2 / g, and then a slurry was prepared with 8 parts of PVDF NMP solution. A negative electrode was prepared on an aluminum foil.
[0155] 正極活物質重量/負極活物質重量の重量比を 1/1. 5とし、セパレータにガラス 繊維、電解液に 1. 5M/リットノレ TEMABFの PC溶液を用い、電極面積 3. 14cm 2の組立式セルを組み立てた。発生するガスはテフ口ン絶縁スリーブの隙間から放出 される仕組みになっている。最初に 1mAで 3. 5Vまで CC充電（定電流充電）を行い 、 3. 5Vで 30分間 CV充電（定電圧充電）を行った。その後、 1mAで 0Vまで CC放電 、 0Vで 30分間 CV放電を行う操作を 5サイクル行った。この時の充放電曲線を電圧 変化量を基準に変換した dQ/dV曲線を図 2— 9に示す。この図から、遷移電圧がサ イタルごとに高くなることが分かる。一方、高電圧での放電容量は遷移電圧が高くな るにもかかわらずほぼ一定であった。 [0155] The weight ratio of positive electrode active material weight / negative electrode active material weight is 1 / 1.5, glass fiber is used for the separator, 1.5M / Litt Nore PC solution of TEMABF is used for the electrolyte, and the electrode area is 3. 14cm. Two assembled cells were assembled. The generated gas is released from the gap between the Teflon insulation sleeves. First, CC charge (constant current charge) was performed up to 3.5V at 1mA, and CV charge (constant voltage charge) was performed at 3.5V for 30 minutes. Thereafter, 5 cycles of CC discharge to 1 V at 1 mA and CV discharge at 0 V for 30 minutes were performed. Figure 2-9 shows the dQ / dV curve obtained by converting the charge / discharge curve at this time based on the voltage change. From this figure, it can be seen that the transition voltage increases with each site. On the other hand, the discharge capacity at high voltage was almost constant despite the high transition voltage.
[0156] 3. 5Vでの開放充電後、充電電圧を 3. 2Vに変更し 10サイクルの充放電試験を行 つた。 3. 2V充電の 10サイクル目の放電容量は、 1. 8V〜3. 2Vの電圧範囲で 46. 9mAh/g (正極重量ベース）であった。高!/、電圧を保ちながら充放電が進んでおり 、エネルギー容量が大きいことが分かった。  [0156] 3. After open charge at 5V, the charge voltage was changed to 3.2V and a 10-cycle charge / discharge test was performed. 3. The discharge capacity at the 10th cycle of 2V charge was 46.9mAh / g (positive electrode weight basis) in the voltage range of 1.8V to 3.2V. It was found that charging / discharging was progressing while maintaining a high voltage, and the energy capacity was large.
[0157] <実施例 B— 2〉  [0157] <Example B-2>
実施例 B— 1と同様の方法で正極及び負極を作成し、組立式セルを作成した。 但し正極用黒鉛には TIMCAL社製黒鉛ティムレックス SFG15 (002層間距離 0. 33 55nm、平均粒子径 8. 8 m、表面積 9. 5m2/g)、負極用活性炭には日本黒鉛製 黒鉛質多孔体 SP440 (002層間距離 0. 3371nm、平均粒子径 13. O ^ m、表面積 440m2/g)を用いた。また正極/負極目付け比は 1/2とした。このセルを用い、最 初に 1mAで 3. 5Vまで CC充電を行い、 3. 5Vで 30分間 CV充電を行った。その後、 1mAで 0Vまで CC放電、 0Vで 30分間 CV放電を行う操作を 5サイクル行った。この 時の充放電曲線を電圧変化量を基準に変換した dQ/dV曲線を図 2— 10に示す。 A positive electrode and a negative electrode were prepared in the same manner as in Example B-1, and an assembly type cell was prepared. However, TIMCAL graphite Timrex SFG15 (002 interlayer distance 0.33 55 nm, average particle size 8.8 m, surface area 9.5 m 2 / g) is used for the positive electrode graphite, and the graphite porous body SP440 (002 interlayer distance 0. 3371nm, the average particle diameter of 13. O ^ m, surface area 440m 2 / g) was used. The positive electrode / negative electrode weight ratio was 1/2. Using this cell, CC charge was first performed to 3.5V at 1mA, and CV charge was performed at 3.5V for 30 minutes. Then, 5 cycles of CC discharge to 0V at 1mA and CV discharge at 0V for 30 minutes were performed. Figure 2-10 shows the dQ / dV curve obtained by converting the charge / discharge curve at this time based on the voltage change.
[0158] 3. 5Vでの開放充電後、充電電圧を 3. 2Vに変更し 10サイクルの充放電試験を行 つた。 3. 2V充電の 10サイクル目の放電容量は、 1. 8V〜3. 2Vの電圧範囲で 47. OmAh/g (正極重量ベース）であった。高!/、電圧を保ちながら充放電が進んでおり 、エネルギー容量が大きかった。  [0158] 3. After open charge at 5V, the charge voltage was changed to 3.2V and a 10-cycle charge / discharge test was performed. 3. The discharge capacity at the 10th cycle of 2V charge was 47. OmAh / g (positive electrode weight basis) in the voltage range of 1.8V to 3.2V. High! /, Charging and discharging progressed while maintaining voltage, and energy capacity was large.
[0159] <比較例 B— 1〉  [0159] <Comparative Example B-1>
実施例 B— 1の方法で正極及び負極を調製した。しかし正極活物質重量/負極活 物質重量の重量比を 1/1に調整した。実施例 B— 1と同様に組立式セルを組み立 てた。 1mAで 3. 2Vまで CC充電を行い、 3. 2Vで 30分間 CV充電を行った。その後 、 1mAで OVまで CC放電し、 OVで 30分間 CV放電を行う操作を 5サイクル行った。 5 サイクル後の遷移電圧の大きな変化は認められなかった。この結果を図 2— 11に示 す。 3. 2V充電の 10サイクル目の放電容量は、 1. 4V〜3. 2Vの電圧範囲で 46. 5 mAh/g (正極重量ベース）であった。放電時の電圧が低電圧までに及んでおり、ェ ネルギー容量面ではやや劣ってレ、た。 A positive electrode and a negative electrode were prepared by the method of Example B-1. However, the weight ratio of the positive electrode active material weight / negative electrode active material weight was adjusted to 1/1. An assembly type cell was assembled in the same manner as in Example B-1. CC charge to 3.2V at 1mA and CV charge at 3.2V for 30 minutes. afterwards 5 cycles of CC discharge to OV at 1 mA and CV discharge for 30 minutes at OV. There was no significant change in transition voltage after 5 cycles. The results are shown in Figure 2-11. 3. The discharge capacity in the 10th cycle of 2V charge was 46.5 mAh / g (positive electrode weight basis) in the voltage range of 1.4V to 3.2V. The voltage at the time of discharge extended to a low voltage, which was slightly inferior in terms of energy capacity.
[0160] <サイクル試験結果〉  [0160] <Cycle test results>
実施例 B— 1と比較例 B— 1で作成した同一の電極構成で、 2032コインセルを作成 し、 2· 3Vと 3. 2Vの間で 10Cレートの 5000回のサイクル試験を行った。  A 2032 coin cell was prepared with the same electrode configuration prepared in Example B-1 and Comparative Example B-1, and a cycle test was performed 5000 times at a 10C rate between 2.3V and 3.2V.
[0161] 5000サイクル後の実施例 B— 1のセルの放電容量は容量維持率は 99. 7%であつ た。一方、 5000サイクル後の比較例 B— 1のセルの容量維持率は 90. 8%であった [0161] The discharge capacity of the cell of Example B-1 after 5000 cycles had a capacity retention rate of 99.7%. On the other hand, the capacity retention rate of the cell of Comparative Example B-1 after 5000 cycles was 90.8%

Claims

請求の範囲 The scope of the claims
[1] 炭素質活物質を含有する正極および負極を備える蓄電デバイスであって、  [1] An electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と高電 圧領域におけるインターカレーシヨン過程を示し、  The electric charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region,
負極における電気的充電力 S、カチオンの吸着により生じ、  Electric charge S at the negative electrode S, generated by adsorption of cations,
完全放電時に、前記負極が正電荷で逆充電された状態になることを特徴とする蓄 電デバイス。  A storage device, wherein the negative electrode is reversely charged with a positive charge when fully discharged.
[2] 前記正極および負極は、初期充電時に正極が最大許容電気量に達する前に、負 極電位が負極での不可逆反応電位を超えるように設定され、  [2] The positive electrode and the negative electrode are set so that the negative electrode potential exceeds the irreversible reaction potential at the negative electrode before the positive electrode reaches the maximum allowable amount of electricity during initial charging.
負極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放電を行 つて製造されたことを特徴とする請求項 1記載の蓄電デバイス。  2. The electric storage device according to claim 1, wherein the electric storage device is manufactured by performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the negative electrode.
[3] サイクリックボルタンメトリー法で充放電曲線を描いた時、正極でのァニオンのインタ 一力レーシヨンが開始された直後に、 dQ/dV値が極大値に達した後、充電電圧の 上昇に伴い dQ/dV値が漸減し、 dQ/dV値が極小値に達した後、再び漸増する d[3] When the charge / discharge curve was drawn by the cyclic voltammetry method, the dQ / dV value reached the maximum immediately after the start of the canyon interaction at the positive electrode. dQ / dV value gradually decreases, dQ / dV value reaches minimum value, and then gradually increases again d
Q/dV曲線を有することを特徴とする請求項 1または 2記載の蓄電デバイス。 3. The electricity storage device according to claim 1, having a Q / dV curve.
[4] 正極へのァニオンのインターカレーシヨンが開始する遷移電圧力 0. 5Vから 1. 75[4] Transition voltage force at which canyon intercalation to the positive electrode starts 0.5 V to 1. 75
Vの範囲であることを特徴とする請求項 1〜3のいずれかに記載の蓄電デバイス。 4. The electricity storage device according to claim 1, wherein the electricity storage device is in a range of V.
[5] 前記負極の動作電圧範囲が、この負極が本来有するカチオン吸着に基づく動作電 圧範囲の 10%以上拡大されていることを特徴とする請求項 1〜3のいずれかに記載 の蓄電デバイス。 [5] The electricity storage device according to any one of claims 1 to 3, wherein an operating voltage range of the negative electrode is expanded by 10% or more of an operating voltage range based on cation adsorption inherent in the negative electrode. .
[6] 前記負極の充電可能な積算容量が、この負極が本来有するカチオン吸着に基づく 充電可能な積算容量の 10〜60%の範囲で拡大されていることを特徴とする請求項 [6] The accumulated capacity capable of being charged in the negative electrode is expanded in a range of 10 to 60% of the accumulated capacity capable of being charged based on cation adsorption inherent in the negative electrode.
；!〜 3のいずれかに記載の蓄電デバイス。 ; The electricity storage device according to any one of! To 3.
[7] 前記開放充電時に、電解液の溶媒の耐電圧より高い電圧まで印加されたことを特 徴とする請求項 2の蓄電デバイス。 7. The electric storage device according to claim 2, wherein a voltage higher than a withstand voltage of the solvent of the electrolytic solution is applied during the open charging.
[8] 前記正極の活物質として黒鉛質材料が使用され、 [8] A graphite material is used as an active material of the positive electrode,
前記負極の活物質として正極の活物質として使用される黒鉛質材料より比表面積 の大きい炭素質材料が使用されることを特徴とする請求項 1〜7のいずれかに記載の 蓄電デバイス。 The carbonaceous material having a larger specific surface area than the graphite material used as the active material of the positive electrode is used as the active material of the negative electrode. Power storage device.
[9] 前記負極で使用される炭素質材料が活性炭であることを特徴とする請求項 8記載 の蓄電デバイス。  9. The electricity storage device according to claim 8, wherein the carbonaceous material used in the negative electrode is activated carbon.
[10] 蓄電デバイスとしての使用時において、充電時の正極電位が 5. 2Vvs. Li+/Liを 超えない範囲で使用されることを特徴とする請求項 1〜9のいずれかに記載の蓄電 デバイス。 [10] The electricity storage device according to any one of claims 1 to 9, wherein when used as an electricity storage device, the positive electrode potential during charging is used in a range not exceeding 5.2Vvs. Li + / Li. device.
[11] 蓄電デバイスとしての使用時において、充電電圧 3. 2V以下の範囲で使用されるこ とを特徴とする請求項;!〜 9のいずれかに記載の蓄電デバイス。  [11] The electricity storage device according to any one of [1] to [9], wherein the electricity storage device is used in a range of a charging voltage of 3.2 V or less when used as an electricity storage device.
[12] 炭素質活物質を含有する正極および負極を備える蓄電デバイスの製造方法であつ て、  [12] A method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
(a)正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と 高電圧領域におけるインターカレーシヨン過程を示し、（b)負極における電気的充電 1S カチオンの吸着により生じ、（c)初期充電時に正極が最大許容電気量に達する 前に、負極電位が負極での不可逆反応電位を超えるように、正極および負極材料の 容量を設定し、  (a) The electrical charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region, (b) the electrical charging at the negative electrode occurs due to the adsorption of 1S cations, (c) the initial stage Set the capacities of the positive and negative electrode materials so that the negative electrode potential exceeds the irreversible reaction potential at the negative electrode before the positive electrode reaches the maximum allowable amount of electricity during charging.
前記負極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放 電を行うことを特徴とする蓄電デバイスの製造方法。  A method for producing an electricity storage device, comprising performing at least one open charge and open charge at a voltage at which an irreversible reaction occurs at the negative electrode.
[13] 前記開放充電時に、負極が有する電荷量に加えて、負極で起きる不可逆反応で消 費した電子に相当する電気量を、正極に正の電荷として蓄電し、 [13] During the open charge, in addition to the charge amount possessed by the negative electrode, an amount of electricity corresponding to electrons consumed by the irreversible reaction occurring at the negative electrode is stored as a positive charge in the positive electrode,
前記開放放電時に、前記正極と負極の電位がバランスするように完全放電し、その 際に、前記不可逆反応を利用して充電した正極の電荷を放出して負極を正電荷で 逆充電することを特徴とする請求項 12記載の製造方法。  At the time of the open discharge, a complete discharge is performed so that the potentials of the positive electrode and the negative electrode are balanced, and at that time, the charge of the positive electrode charged by using the irreversible reaction is discharged and the negative electrode is reversely charged with a positive charge. The manufacturing method according to claim 12, characterized in that:
[14] 前記負極での不可逆反応が、電解液の溶媒の還元分解であることを特徴とする請 求項 12または 13記載の製造方法。 [14] The production method according to claim 12 or 13, wherein the irreversible reaction at the negative electrode is reductive decomposition of a solvent of the electrolytic solution.
[15] 炭素質活物質を含有する正極および負極を備える蓄電デバイスであって、 [15] An electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と高電 圧領域におけるインターカレーシヨン過程を示し、  The electric charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region,
負極における電気的充電力 S、カチオンの吸着により生じ、 完全放電時に、前記負極が、放電されずに残存する負電荷で充電されていること を特徴とする蓄電デバイス。 Electric charge S at the negative electrode S, generated by adsorption of cations, An electricity storage device, wherein the negative electrode is charged with a negative charge remaining without being discharged at the time of complete discharge.
[16] 前記正極および負極は、初期充電時に負極が最大許容電気量に達する前に、正 極電位が正極での不可逆反応電位を超えるように設定され、 [16] The positive electrode and the negative electrode are set such that the positive electrode potential exceeds the irreversible reaction potential at the positive electrode before the negative electrode reaches the maximum allowable amount of electricity during initial charging.
正極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放電を行 つて製造されたことを特徴とする請求項 15記載の蓄電デバイス。  16. The electric storage device according to claim 15, wherein the electric storage device is manufactured by performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
[17] 正極へのァニオンのインターカレーシヨンが開始する遷移電圧力 1. 75V力、ら 2. 5[17] Transition voltage force at which canyon intercalation to the positive electrode begins 1. 75V force, et al. 2.5
Vの範囲であることを特徴とする請求項 15または 16記載の蓄電デバイス。 The electric storage device according to claim 15 or 16, wherein the electric storage device is in a range of V.
[18] 正極の充電可能な積算容量が、負極の充電可能な積算容量の 95%以下であるこ とを特徴とする請求項 15〜； 17のいずれかに記載の蓄電デバイス。 [18] The electricity storage device according to any one of [15] to [17], wherein the accumulated capacity capable of charging the positive electrode is 95% or less of the accumulated capacity capable of charging the negative electrode.
[19] 前記開放充電時の不可逆反応電荷量が、負極が本来有するカチオン吸着に基づ く電荷量の 10〜60%であることを特徴とする請求項 16記載の蓄電デバイス。 19. The electricity storage device according to claim 16, wherein the irreversible reaction charge amount during the open charge is 10 to 60% of the charge amount based on cation adsorption inherent in the negative electrode.
[20] 前記不可逆反応が、電解液の溶媒の分解反応であることを特徴とする請求項 16記 載の蓄電デバイス。 20. The electricity storage device according to claim 16, wherein the irreversible reaction is a decomposition reaction of a solvent of the electrolytic solution.
[21] 開放充電時に、電解液の耐電圧より高い電圧まで印加されたことを特徴とする請求 項 20記載の蓄電デバイス。  21. The electricity storage device according to claim 20, wherein a voltage higher than a withstand voltage of the electrolytic solution is applied during open charging.
[22] 前記不可逆反応が、添加された材料の反応を伴うことを特徴とする請求項 16記載 の蓄電デバイス。 22. The electricity storage device according to claim 16, wherein the irreversible reaction is accompanied by a reaction of an added material.
[23] 前記正極の活物質として黒鉛質材料が使用され、 [23] A graphite material is used as an active material of the positive electrode,
前記負極の活物質として正極の活物質として使用される黒鉛質材料より比表面積 の大きい炭素質材料が使用されることを特徴とする請求項 15〜22のいずれかに記 載の蓄電デバイス。  23. The electricity storage device according to claim 15, wherein a carbonaceous material having a specific surface area larger than that of a graphite material used as a positive electrode active material is used as the negative electrode active material.
[24] 前記負極で使用される炭素質材料が活性炭であることを特徴とする請求項 23記載 の蓄電デバイス。  24. The electricity storage device according to claim 23, wherein the carbonaceous material used in the negative electrode is activated carbon.
[25] 蓄電デバイスとしての使用時において、充電時の正極電位が 5. 2Vvs. Li+/Liを 超えない範囲で使用されることを特徴とする請求項 15〜24のいずれかに記載の蓄 電デバイス。 [25] The storage device according to any one of claims 15 to 24, wherein the positive electrode potential during charging does not exceed 5.2 Vvs. Li + / Li when used as a storage device. Electric device.
[26] 蓄電デバイスとしての使用時において、充電電圧 3. 5V未満の範囲で使用されるこ とを特徴とする請求項 15〜24のいずれかに記載の蓄電デバイス。 [26] When used as an electricity storage device, it must be used in a range where the charging voltage is less than 3.5V. The electricity storage device according to any one of claims 15 to 24, wherein:
[27] 炭素質活物質を含有する正極および負極を備える蓄電デバイスの製造方法であつ て、 [27] A method for producing an electricity storage device comprising a positive electrode and a negative electrode containing a carbonaceous active material,
(a)正極における電気的充電過程が、低電圧領域におけるァユオンの吸着過程と 高電圧領域におけるインターカレーシヨン過程を示し、（b)負極における電気的充電 1S カチオンの吸着により生じ、（c)初期充電時に負極が最大許容電気量に達する 前に、正極電位が正極での不可逆反応電位を超えるように、正極および負極材料の 容量を設定し、  (a) The electrical charging process at the positive electrode shows the adsorption process of the ayuon in the low voltage region and the intercalation process in the high voltage region, (b) the electrical charging at the negative electrode occurs due to the adsorption of 1S cations, (c) the initial stage Set the capacities of the positive and negative electrode materials so that the positive electrode potential exceeds the irreversible reaction potential at the positive electrode before the negative electrode reaches the maximum allowable amount of electricity during charging.
前記正極で不可逆反応が起きる電圧で、少なくとも 1回の開放充電および開放放 電を行うことを特徴とする蓄電デバイスの製造方法。  A method for manufacturing an electricity storage device, comprising performing at least one open charge and open discharge at a voltage at which an irreversible reaction occurs at the positive electrode.
[28] 前記開放充電時に、正極が有する電荷量に加えて、正極で起きる不可逆反応で消 費した正孔に相当する電気量を、負極に負の電荷として蓄電し、 [28] At the time of the open charge, in addition to the amount of charge of the positive electrode, the amount of electricity corresponding to the holes consumed by the irreversible reaction occurring at the positive electrode is stored as a negative charge in the negative electrode,
前記開放放電時に、前記正極と負極の電位がバランスするように完全放電し、その 際に、前記不可逆反応を利用して蓄電した負極の電荷が、負極に残存することを特 徴とする請求項 27記載の製造方法。  2. The discharge according to claim 1, wherein during the open discharge, a complete discharge is performed so that the potentials of the positive electrode and the negative electrode are balanced, and at that time, the charge of the negative electrode stored using the irreversible reaction remains in the negative electrode. 27. The production method according to 27.
[29] 前記正極での不可逆反応が、電解液の溶媒の酸化分解であることを特徴とする請 求項 27または 28記載の製造方法。 [29] The production method according to claim 27 or 28, wherein the irreversible reaction at the positive electrode is oxidative decomposition of a solvent of the electrolytic solution.
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JPH08107047A (en) * 1994-10-04 1996-04-23 Petoca:Kk Electric double-layer capacitor
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JPH0757978A (en) * 1993-08-18 1995-03-03 Okamura Kenkyusho:Kk Charging method for electric double layer capacitor
JPH08107047A (en) * 1994-10-04 1996-04-23 Petoca:Kk Electric double-layer capacitor
JPH11307404A (en) * 1998-04-24 1999-11-05 Isuzu Advanced Engineering Center Ltd Electric double layer capacitor and its manufacture, ana active carbon for positive electrode

Cited By (3)

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Publication number Priority date Publication date Assignee Title
EP3355329A4 (en) * 2015-12-16 2019-03-27 Shanghai Aowei Technology Development Co., Ltd. Lithium ion capacitor and formation method therefor
WO2022107892A1 (en) * 2020-11-20 2022-05-27 株式会社村田製作所 Secondary battery, secondary battery control system, and battery pack
JP7464146B2 (en) 2020-11-20 2024-04-09 株式会社村田製作所 Secondary battery, secondary battery control system and battery pack

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