JP2014114199A - Novel carbonaceous material and use of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel carbonaceous material capable of increasing the amount of intercalation of anions or cations when being used as a power storage device, and an application technology of the same.SOLUTION: The amount of intercalation of anions or cations can be increased by using carbonaceous materials as an electrode of power storage devices, where the carbonaceous materials have a ratio of a peak intensity at 1350 cmto a peak intensity at 1580 cm, in a Raman spectrum, of more than 0.33 and has a half value width at 1580 cmof more than 22 cm.

Description

  The present invention relates to a novel carbonaceous material and use thereof, and more particularly to a novel carbonaceous material that can be used for a high-capacity electricity storage device having an increased amount of anion or cation intercalation and the use thereof. .

  Conventionally, small batteries have been developed to reduce the size and weight of various portable devices such as personal computers and mobile phones. In order to reduce the size and weight of various portable devices, it is essential that the energy density of the battery as a power source is high. In addition to small batteries, large batteries are also being developed as power storage devices mounted on electric vehicles and hybrid vehicles. Such a large battery is required to have a high energy density and a high output density.

Research and development of lithium ion secondary batteries, electric double layer capacitors, and the like have been actively conducted to meet the above requirements. For example, Patent Document 1 discloses a carbonaceous material having a layered structure in which a plurality of amorphous parts are dispersed on the (002) plane, and the average area of the amorphous parts is 1.5 nm ² or more. A certain carbonaceous material or the like is described, and it is disclosed that when this is used in a power storage device, the amount of ion intercalation can be increased to realize a high capacity of the power storage device.

JP 2010-254537 A

  As described above, various technical developments have been made on power storage devices such as lithium ion secondary batteries and electric double layer capacitors. However, in the field of power storage devices, it is very important to increase the capacity of power storage devices, and in order to make it possible to use such power storage devices as power sources for automobiles and general equipment, further increase in capacity is required. It is done.

  Recently, a new market has emerged as storage batteries for automobiles such as hybrid cars and electric cars, and new energy systems such as solar batteries and wind power generation, and the market for lithium-ion batteries will greatly expand in the future. The demand for higher capacity is also high from the point of expectation.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a novel carbonaceous material that can increase the amount of anion or cation intercalation when used in an electricity storage device, and a technology for using the same. Is to provide.

As a result of intensive studies to achieve the above object, the inventors of the present invention have a peak intensity ratio of two Raman bands (I ₁₃₅₀ / I ₁₅₈₀ ) and a half band width of a Raman band of ₁₅₈₀ cm ⁻¹ greater than a predetermined value. When the carbonaceous material is used as the positive electrode active material of the power storage device, the amount of anion or cation intercalation can be increased, and the capacity can be increased compared to the case of using a conventional carbonaceous material. The inventors have found a new finding that it can be achieved and the charge / discharge cycle performance is excellent, and have completed the present invention. That is, the present invention includes the following configurations.

(1) greater than the ratio of the peak intensity of 1350 cm ^-1 is 0.33 to the peak intensity of 1580 cm ^-1 in the Raman spectrum, and half-width 22 cm ^-1 is larger than the carbonaceous material of the 1580 cm ^-1.

  (2) The carbonaceous material according to (1), wherein the hexagonal graphite layer further has a (002) plane spacing of 3.3 to 3.5 mm by X-ray diffraction.

  (3) The carbonaceous material according to (1) or (2), which is graphite.

  (4) An electricity storage device comprising the carbonaceous material according to any one of (1) to (3) as an active material.

  (5) A positive electrode including the carbonaceous material according to any one of (1) to (3) above and a negative electrode including a carbonaceous material from which a cation can be inserted and released between layers, and filled with a nonaqueous electrolyte solution An electricity storage device.

  (6) The nonaqueous electrolytic solution is an electrolytic solution in which lithium ions are dissolved, the negative electrode is a negative electrode including a carbonaceous material capable of inserting and extracting lithium ions, and the carbonaceous material included in the negative electrode is: The electricity storage device according to (5), wherein lithium ions are occluded in advance.

  (7) The electrical storage device according to (6), wherein the carbonaceous material included in the negative electrode is obtained by electrochemically reacting the negative electrode and lithium metal.

  (8) The electric storage device according to (6) or (7), wherein the potential of the negative electrode is 0.01 V or more and 0.25 V or less with respect to metallic lithium.

  (9) The electricity storage device according to any one of (5) to (8), wherein the carbonaceous material included in the negative electrode is graphite or non-graphitizable carbon.

  The carbonaceous material according to the present invention can increase the amount of anion or cation intercalation. For this reason, high capacity can be achieved by using it as an electrode of an electricity storage device. Moreover, the charge / discharge cycle performance is also excellent.

It is a schematic diagram which shows the structure of the basic cell of the electrical storage device which concerns on one Embodiment of this invention. It is a schematic diagram which shows the structure of the test apparatus for the performance evaluation of the carbonaceous material which concerns on the Example of this invention.

  An embodiment of the present invention will be described in detail below. All academic and patent documents mentioned in this specification are hereby incorporated by reference. Unless otherwise specified in this specification, “A to B” indicating a numerical range means “A or more and B or less”. “%” Means “% by weight” and “parts” means “parts by weight”.

<1. Carbonaceous material>
Long carbonaceous material according to the present invention is greater than the ratio of the peak intensity of 1350 cm ^-1 is 0.33 to the peak intensity of 1580 cm ^-1 in the Raman spectrum, and those half-value width of 1580 cm ^-1 is greater than 22 cm ^-1 The other specific configuration is not particularly limited.

  Furthermore, the carbonaceous material according to the present invention preferably has a (002) plane spacing of 3.3 to 3.5 mm by X-ray diffraction of the hexagonal graphite layer. Further, graphite is more preferable. Graphite has a layered structure on the (002) plane. The (002) plane is intended to be a carbon 002 plane (plane parallel to the graphite layer) measured by X-ray diffraction. Such a carbonaceous material is preferably graphite, but is not limited to graphite, and a carbonaceous material having a layered structure, particularly a (002) plane, can be suitably employed. If the interplanar spacing of the (002) plane by X-ray diffraction is within this range, the amount of anion or cation intercalation into the electrode material can be obtained by using this carbonaceous material as an active material for the electrode of the electricity storage device. Can be increased.

  In the present invention, “Raman spectrum” is intended to be obtained by irradiating a carbonaceous material with an argon laser (light source wavelength: 514.5 nm).

Here, the “ratio of the peak intensity at 1350 cm ^{−1 to} the peak intensity at 1580 cm ⁻¹ by Raman spectrum” reflects the ratio of the edge of the graphite crystal surface, and the ratio of the edge increases as the ratio increases. There is a tendency to be crystalline. In the present specification, it may be referred to as “peak intensity ratio of two Raman bands (I ₁₃₅₀ / I ₁₅₈₀ )”.

Further, the peak intensity of 1350 cm ^-1 by Raman spectra may be a peak intensity at around 1350 cm ^-1, for ^example, it can be evaluated from the peak intensity of 1340cm ^-1 ~1360cm -1. It is preferable to measure a peak intensity of 1350 cm ⁻¹ . Similarly, the peak intensity of 1580 cm ^-1 by Raman spectra may be a peak intensity at around 1580 cm ^-1, for ^example, it can be evaluated from the peak intensity of 1570cm ^-1 ~1590cm -1. In addition, it is preferable to measure the peak intensity of 1580 cm ⁻¹ .

The “half-width of 1580 cm ⁻¹ by Raman spectrum” reflects the degree of graphitization (completeness of local graphite structure). If this value is reduced, the proportion of the basal plane increases and the orientation becomes high. On the other hand, when this value increases, the degree of graphitization decreases and the film becomes amorphous.

That is, in the present invention, greater than the ratio of the peak intensity of 1350 cm ^-1 is 0.33 to the peak intensity of 1580 cm ^-1 by Raman spectrum, and the half width of 1580 cm ^-1 is called 22 cm ^-1 is larger than the carbonaceous material, the electrode In other words, it has been found that the physical properties of a carbonaceous material that are particularly preferable for use as an active material are found.

In the carbonaceous material according to the present invention, the peak intensity ratio (I ₁₃₅₀ / I ₁₅₈₀ ) of two Raman bands is more preferably 0.35 or more, further preferably 0.38 or more, and 0.40. The above is particularly preferable. The upper limit is not particularly limited, but is preferably 0.60 or less, for example. Within this numerical range, it is possible to increase the amount of anion or cation intercalation between the layers of the carbonaceous material.

Further, the carbonaceous material according to the present invention, more preferably the half-width of 1580 cm ^-1 in the Raman spectrum is 23cm ^-1 or more, more preferably 24cm ^-1 or more. Although it does not specifically limit about an upper limit, For example, it is preferable that it is 30 cm <^-1> or less. Within this numerical range, it is possible to increase the amount of anion or cation intercalation between the layers of the carbonaceous material.

<2. Manufacturing method of carbonaceous material>
Various methods can be used as a method for producing the carbonaceous material, and the method is not particularly limited. For example, the hydrocarbon compound can be manufactured by heat treatment. Specifically, after the concentration of the hydrocarbon compound is adjusted with argon gas, it is sprayed onto the surface of a heated quartz substrate, and a carbonaceous material is generated and deposited on the substrate.

  Examples of hydrocarbon compounds include alkyne hydrocarbons such as acetylene, propyne and butyne; aromatic hydrocarbons such as benzene, xylene and toluene; polycyclic carbons such as naphthalene, methylnaphthalene, anthracene, phenanthrene, acenaphthene, acenaphthylene and pyrene. Mention may be made of hydrogen; or substances containing these.

  Such a hydrocarbon compound is heat-treated in a non-oxidizing atmosphere. As the non-oxidizing gas, helium, argon or the like is used. In addition, the heating temperature is not particularly limited as long as it is a temperature at which carbonization / graphitization can be performed. For example, 500 ° C to 3000 ° C is preferable, 1000 ° C to 2000 ° C is more preferable, and 1200 ° C to 1500 ° C is more. preferable.

  The production method is not particularly limited, but for example, the method described in JP-A-62-202809 can be used.

Other methods include, for example, an electrochemical method. For example, as the raw material, the half value width 18cm argon laser (light source wavelength 514.5 nm) and the ratio of the peak intensity of 1350 cm ^-1 by Raman spectrum to the peak intensity of 1580 cm ^-1 is 0.05 to 0.3 1580 cm ^-1 An electrode is manufactured by forming a carbonaceous material having a layered structure of ^{−1 to} 22 cm ⁻¹ as a main component on a current collector, using it as a positive electrode, and using an activated carbon as a main component on the negative electrode side Using the electrode formed in the above, charging and discharging are performed by impregnating with a non-aqueous electrolyte solution. This material can be formed by this method.

Specifically, it can be obtained by taking out from the positive electrode obtained by a production method including the following steps (a) to (d).
(A) coating the surface of the electrode plate with a carbonaceous material having a layered structure to prepare a positive electrode;
(B) a step of preparing a negative electrode by coating the surface of the electrode plate with a carbonaceous material having a mass four times or more the mass of the carbonaceous material of the positive electrode;
(C) making the positive electrode and the negative electrode face each other in a nonaqueous electrolytic solution containing an anion capable of intercalation between the layers of the carbonaceous material of the positive electrode;
(D) The voltage application process which makes charging voltage at the time of charge larger than 2.25V and 3.5V or less and performs at least one charging / discharging cycle.

  The details of such a method are described in detail in Japanese Patent Application Laid-Open No. 2010-254537, and therefore the description thereof is incorporated here and the description thereof is omitted.

  However, since the carbonaceous material according to the present invention cannot be obtained simply by performing the method described in JP2010-254537A, it is preferable to perform the steps described below.

<A. Selection of electrolyte>
As the electrolyte in the non-aqueous electrolyte in the step (c) “the step of facing the positive electrode and the negative electrode in a non-aqueous electrolyte containing an anion capable of intercalation between layers of the carbonaceous material of the positive electrode” It is preferable to use triethylmethylammonium tetrafluoroborate (TEMA.BF ₄ ).

When using the TEMA • BF ₄ as an electrolyte, two Ramans in the carbonaceous material are compared to using other electrolytes (for example, triethylmethylammonium hexafluorophosphate (TEMA • PF ₆ )). Both the peak intensity ratio (I ₁₃₅₀ / I ₁₅₈₀ ) of the band and the half-value width of the Raman band of ₁₅₈₀ cm ⁻¹ can be in a desired range.

<B. Selection of solvent>
Further, in the step (c), “in the step of making the positive electrode and the negative electrode face each other in a nonaqueous electrolytic solution containing an anion capable of intercalating between the layers of the carbonaceous material of the positive electrode” in the nonaqueous electrolytic solution As the solvent, a solvent containing a cyclic carbonate and a chain carbonate is preferably used. Here, although it does not specifically limit about each carbonate to be used, For example, a propylene carbonate (PC) can be used conveniently as a cyclic carbonate. As the chain carbonate, for example, at least one selected from the group consisting of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC), or a combination thereof can be suitably used.

  Moreover, although mass ratio of a cyclic carbonate and a chain carbonate is not specifically limited, For example, 1: 1 to 1: 5 can be illustrated. However, since the solubility of the electrolyte tends to decrease as the amount of the chain carbonate increases, it is preferable that the range does not cause such a problem. For example, the mass ratio of cyclic carbonate to chain carbonate is particularly preferably 1: 1.

The electrolyte in the non-aqueous electrolyte is not particularly limited, but it is preferable to use, for example, triethylmethylammonium tetrafluoroborate (TEMA.BF ₄ ) as described in the section <A>.

According to the manufacturing method of this aspect, in the carbonaceous material, the peak intensity ratio (I ₁₃₅₀ / I ₁₅₈₀ ) of the two Raman bands and the half band width of the Raman band of ₁₅₈₀ cm ⁻¹ are both set to a desired range. it can.

<C. Selection of other solvents>
In addition, in the step (c) “the step of facing the positive electrode and the negative electrode in a nonaqueous electrolytic solution containing an anion capable of intercalating between layers of the carbonaceous material of the positive electrode”, as the nonaqueous electrolytic solution, It is preferable to use a nonaqueous electrolytic solution containing an electrolyte containing an anion that can be intercalated between layers of a carbonaceous material and a fluorine-containing organic solvent.

  As such a fluorine-containing organic solvent, it is preferable to use a fluorine-containing organic solvent instead of carbonates or lactones from the following viewpoints. That is, even when a voltage of 3 V or higher is applied, chemical decomposition hardly occurs. Further, it is possible to avoid the risk of ignition during overcharge / overheating due to the low flash point and high combustibility. In addition, since the viscosity is difficult to increase, the decrease in conductivity can be reduced even at low temperatures, and the decrease in output can be suppressed (low temperature characteristics). It is easy to use because the hydrolyzability can be lowered. The electrolyte solution 14 of the electrolyte solution 14 is particularly preferably a non-aqueous electrolyte solution that is highly soluble in electrolyte salt, stable even under basic conditions, and excellent in compatibility with a hydrocarbon solvent. As such a fluorine-containing organic solvent, an electrolytic solution is represented by the following formula (I):

(Wherein X ^{1 to} X ⁶ are the same or different, and all are H, F, Cl, CH ₃ or a fluorine-containing methyl group; provided that at least one of X ^{1 to} X ⁶ is a fluorine-containing methyl group) It is preferable that it is a fluorine-containing lactone shown by these.

^The fluorine-containing methyl group in X 1 to X ⁶ _are, -CH 2 F, a -CHF ₂ and CF _3, -CF ₃ terms withstand voltage is good is preferred. The fluorine-containing methyl group may be substituted for all of X ^{1 to} X ⁶ or only one. Preferably, the number is 1 to 3, particularly 1 to 2, in view of good solubility of the electrolyte salt. Further, the substitution position of the fluorine-containing methyl group is not particularly limited, but since the synthesis yield is good, X ³ and / or X ⁴ is particularly X ⁴ is a fluorine-containing methyl group, particularly —CF _3. Is preferred. X ^{1 to} X ⁶ other than the fluorine-containing methyl group are H, F, Cl or CH ₃ , and H is particularly preferable from the viewpoint of good solubility of the electrolyte salt.

  In the fluorine-containing lactone, the atom other than the fluorine-containing methyl group bonded to the carbon atom constituting the lactone ring is preferably F and / or H. The electrolyte salt is preferably an ammonium salt, and particularly preferably a tetraalkyl quaternary ammonium salt, a spirobipyridinium salt, or an imidazolium salt.

  The fluorine content of the fluorine-containing lactone is 10% by mass or more, preferably 20% by mass or more, particularly 30% by mass or more, and the upper limit is usually 76% by mass, preferably 55% by mass. The method for measuring the fluorine content of the whole fluorine-containing lactone can be measured by a usual method such as a combustion method.

  Since fluorine-containing lactone is contained, even when adding fluorine-containing ether that improves flame retardancy, it is difficult to separate into two layers and a uniform state can be obtained.

Examples of the fluorine-containing organic solvent include 4-trifluoromethyl-1,3-dioxolan-2-one and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether ( HCF ₂ CF ₂ CH ₂ OCF ₂ CF ₂ H).

  Moreover, the solvent as described above can be preferably used those described in JP 2008-016560 A, JP 2010-226100 A, and JP 2011-097118 A.

  Moreover, about the electrolyte to be used, a conventionally well-known thing can be used and it does not specifically limit. For example, SBP-PF6 of Nippon Carlit Co., Ltd. can be mentioned.

According to the manufacturing method of this embodiment, in the carbonaceous material, both the peak intensity ratio of two Raman bands (I ₁₃₅₀ / I ₁₅₈₀ ) and the half band width of the Raman band of ₁₅₈₀ cm ⁻¹ are set to a desired range. Can do.

  The carbonaceous material thus obtained is the carbonaceous material according to the present invention. Since the carbonaceous material according to the present invention has the physical properties described above, it can be said that it has lower crystallinity than graphite and contains many amorphous parts. Further, it can be presumed that the edge surface ratio is increased as a result of cleaving the plate-like structure without impairing the regularity of the graphite layered structure. By using such a carbonaceous material, the amount of anions or cations inserted / extracted between layers increases. For this reason, when this carbonaceous material is used as an electrode of an electricity storage device, the capacity of the electricity storage device can be increased. In addition, the buffering action against the expansion and contraction of the interlayer distance of the crystal structure due to the insertion or desorption of anions or cations is activated, suppressing the collapse of the crystal structure, improving the charge / discharge cycle performance in addition to increasing the capacity. It can also be improved.

<3. Power storage device>
The electricity storage device according to the present invention is not particularly limited as long as it includes the above-described carbonaceous material according to the present invention as an active material. In this specification, the “electric storage device” includes a secondary battery.

  According to another aspect, there is provided an electricity storage device comprising a positive electrode including a carbonaceous material according to the present invention and a negative electrode including a carbonaceous material from which a cation can be inserted and released between layers, and being filled with a nonaqueous electrolytic solution. It is preferable. In this specification, “non-aqueous electrolyte solution” is used synonymously with an organic solvent electrolyte solution.

  The non-aqueous electrolytic solution is an electrolytic solution in which lithium ions are dissolved, the negative electrode is a negative electrode including a carbonaceous material capable of inserting and extracting lithium ions, and the carbonaceous material included in the negative electrode is lithium More preferably, ions are occluded.

  The carbonaceous material included in the negative electrode is preferably obtained by electrochemically reacting the negative electrode and lithium metal. As a method of electrochemically reacting the negative electrode and the lithium metal in order to occlude lithium ions in advance in the negative electrode, for example, the metal foil of the negative electrode current collector and the lithium metal are electrochemically short-circuited and electrolysis is performed. This is done by pouring the liquid into the container. Moreover, the lithium electrode arrange | positioned so that it may not contact a negative electrode directly may be provided, and an electric current may be sent between a negative electrode and a lithium electrode.

  The amount of lithium ion to be stored in advance is a (mAh), the cell capacity when the power storage device is charged to a predetermined voltage after storage is b (mAh), and the negative electrode is 3.0 VLi / Li + to 0.01 VLi / When the capacity when charged to Li + is c (mAh), the negative electrode capacity is determined so that 3 ≦ c / b ≦ 10, and preferably 1.2 ≦ c / a ≦ 5. .

  The negative electrode capacity is preferably determined so as to satisfy 3 ≦ c / b ≦ 10. If it is in this range, since the negative electrode capacity is not too small compared with the electricity storage device capacity, a sufficient amount of lithium ions can be occluded in advance in the negative electrode. Further, an increase in the weight of the negative electrode can be suppressed and an increase in the weight of the power storage device can be prevented, so that the capacity density of the power storage device does not decrease.

  The amount of lithium ions stored in advance is preferably 1.2 ≦ c / a ≦ 5. Within this range, the amount of lithium ions previously occluded in the negative electrode is an appropriate amount, so that the capacity density can be maintained, and the capacity reduction during float charging can be prevented.

  Furthermore, the potential of the negative electrode is preferably 0.01 V or more and 0.25 V or less based on metallic lithium. By setting it within this range, the charge / discharge cycle performance is improved.

  Further, the carbonaceous material included in the negative electrode is preferably graphite, non-graphitizable carbon, natural graphite, artificial graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, etc., particularly graphite or non-graphitizable carbon. Is preferably used.

  As a method of manufacturing an electrode from a carbonaceous material, a carbon material that can occlude and desorb lithium ions in a slurry in which a mixture of carboxymethyl cellulose and SBR rubber as a binder, polyvinylidene fluoride, polyamideimide, polyimide, or the like is dissolved, and a conductive aid. It is preferable to disperse the material, apply this liquid onto the current collector by the doctor blade method or the like, and dry it. The amount of the binder contained in the electrode is preferably 1 to 20% by weight.

  As the carbonaceous material included in the negative electrode, for example, those described in JP 2009-260187 A may be used.

Further, as solute lithium salts in the non-aqueous electrolyte, LiPF ₆ , LiBF ₄ , LiCIO ₄ , LiN (CF ₃ SO ₂ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC ( _{SO 2 CF 3) 3, LIAsF} 6, and one or more is preferably selected from the group consisting of LiSbF _6.

  The electrolyte concentration of the lithium salt in the non-aqueous electrolyte is preferably 0.5 to 2.5 mol / L. The concentration of the entire electrolyte is more preferably 0.75 to 2.0 mol / L.

  Examples of the solvent for the electrolytic solution include propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, sulfolane, and dimethoxyethane. These can be used alone or as a mixed solution of two or more. .

  Moreover, it is preferable to constitute a cell through a cellulose-based or polyolefin-based separator.

  In addition, conventionally well-known things can be used as a non-aqueous electrolyte solution, a solute, and a separator material, and use of things other than what was mentioned above is not excluded.

  Moreover, in the electrical storage device which concerns on this invention, it is preferable to perform charging / discharging in the range whose maximum voltage of the charging / discharging voltage of the said electrical storage device is 5.0V or more and 5.4V or less.

  In the cell (power storage device) having the above-described configuration, it is possible to generate a larger storage capacity than a power storage device such as a known lithium ion battery by performing charge and discharge in the range of the maximum voltage of 5.0 V to 5.4 V. it can. For example, according to the electricity storage device of the present invention, a conventional hybrid capacitor (charge / discharge voltage range of about 0V to 3.5V), EDLC (charge / discharge voltage range of about 0V to 2.7V), lithium ion capacitor (charge / discharge voltage) Either the capacity density or the output density compared to the conventional high-capacity lithium ion battery (charge / discharge voltage range of about 2.8V to 3.6V). On the other hand, it has the effect of being large in both points.

  Here, “the range where the maximum voltage is 5.0 V or more and 5.4 V or less” intends the range of the upper limit voltage in the charge / discharge voltage of the electricity storage device. The effect is small because the charge / discharge capacity is reduced as the value of the maximum voltage of the charge / discharge voltage is lowered. However, in the electricity storage device according to the present invention, the maximum voltage of the charge / discharge voltage is 5.0 V or more. Discharge capacity is obtained. On the other hand, if the upper limit voltage exceeds 5.4 V, the decomposition of the electrolytic solution proceeds and the characteristics deteriorate, which is not preferable. In addition, the lower limit voltage in the charging / discharging voltage of an electrical storage device should just be 3V vicinity, and is not specifically limited.

  As described above, the electricity storage device according to the present invention is a high-capacity storage battery having a maximum charge / discharge voltage of 5.0 V to 5.4 V. For this reason, in addition to various portable devices such as mobile phones and notebook computers, it can be suitably used as a storage battery for power storage in combination with a storage battery for an automobile such as a hybrid vehicle or an electric vehicle, or a new energy system such as a solar battery or wind power generation.

  Hereinafter, an embodiment of an electricity storage device according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a basic cell 10 which is an example of an electricity storage device according to the present invention. In FIG. 1, 1 is a positive electrode (carbonaceous material according to the present invention) which is a polarizable electrode, 2 is a positive electrode current collector foil and external extraction electrode (aluminum foil), 3 is a separator (cellulose), and 4 is a carbonaceous electrode. Negative electrode (main component: graphite), 5 is a negative electrode current collector foil and an external extraction electrode (copper foil), 6 is a lithium metal, and 7 is a lithium metal electrode extraction electrode (nickel). A lithium metal 6 is pressure-bonded to the lithium metal electrode lead electrode 7 and a lithium electrode is disposed so as not to be in direct contact with the negative electrode 4.

  A positive electrode current collector foil and an external extraction electrode 2 are disposed so that the positive electrode 1 and the negative electrode 4 are opposed to each other with a cellulose-based porous separator 3 therebetween, and the lithium metal 6 is made of nickel as a lithium ion doping electrode. An electrode (lithium metal electrode lead-out electrode) 7 that is provided with an electrode crimped to an electric body and is led out is provided and covered with an aluminum laminate film. An electrolytic solution is impregnated, and the laminate exterior is sealed to produce an electricity storage device cell.

  Lithium ions can be previously stored in the negative electrode 4 by short-circuiting the negative electrode 4 and the lithium electrode of the cell 10 thus manufactured through an external circuit. For example, the occlusion may be terminated when the amount of lithium ions stored in the negative electrode measured using an external circuit reaches 70% of the theoretical storage amount.

Moreover, the following invention is also included by the electrical storage device which concerns on this invention.
1. A positive electrode using as an active material a carbonaceous material in which an anion is inserted and desorbed between layers, a negative electrode using a carbonaceous material in which a cation is inserted and released between layers as an active material, a separator between the positive electrode and the negative electrode, lithium consists nonaqueous electrolyte prepared by dissolving the salt, the carbonaceous material used for the positive electrode, the ratio of the peak intensity of 1350 cm ^-1 to the peak intensity of 1580 cm ^-1 in the argon laser Raman spectrum is greater than 0.33, 1580 cm ^-1 A non-aqueous electrolyte secondary battery having a full width at half maximum of greater than 22 cm ⁻¹ .
2. A positive electrode using as an active material a carbonaceous material in which an anion is inserted and desorbed between layers, a negative electrode using a carbonaceous material in which a cation is inserted and released between layers as an active material, a separator between the positive electrode and the negative electrode, lithium consists nonaqueous electrolyte prepared by dissolving the salt, the carbonaceous material used for the positive electrode, the ratio of the peak intensity of 1350 cm ^-1 to the peak intensity of 1580 cm ^-1 in the argon laser Raman spectrum is greater than 0.33, 1580 cm ^-1 A non-aqueous electrolyte secondary solution in which the half-value width at the peak of is greater than 22 cm ⁻¹ and the (002) plane spacing by X-ray diffraction of the hexagonal graphite layer is 3.3 to 3.5 Å (angstrom) battery.
3. The nonaqueous electrolyte secondary battery according to 1 or 2, wherein lithium ions are inserted as a cation in advance into the carbonaceous material of the negative electrode, and the potential of the negative electrode is 0.01 to 0.25 V with respect to metal lithium.
4). 4. The nonaqueous electrolyte secondary battery according to 3, wherein the upper limit voltage of the battery operating voltage range is 5.0 to 5.4V.

  The present invention is not limited to the configurations described above, and various modifications can be made within the scope described in the specification, and implementations obtained by appropriately combining technical means disclosed in different embodiments. The form is also included in the technical scope of the present invention. Moreover, all the literatures described in this specification are used as reference. EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited only to this Example.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

[Example 1]
Manufacture of the carbonaceous material used for a positive electrode was performed as follows. The concentration of acetylene was adjusted with argon gas and sprayed onto the surface of a quartz substrate heated to 1200 ° C. to produce and deposit a carbonaceous material on the substrate. The ratio of the peak intensity of 1350 cm ^-1 to the peak intensity of 1580 cm ^-1 in the argon laser Raman spectra of carbonaceous material produced in this way 0.35, the half width at the peak of 1580 cm ^-1 is 22.2Cm ^-1 met It was. Also, the (002) plane spacing by XRD diffraction was 3.36 mm.

[Example 2]
A carbonaceous material was produced under the same apparatus and the same conditions as in Example 1 except that the heating and holding temperature of the quartz substrate surface was set to 1000 ° C. The ratio of the peak intensity at 1350 cm ^{−1 to} the peak intensity at 1580 cm ⁻¹ in the argon laser Raman spectrum of the carbonaceous material obtained as the second example is 0.42, and the half width at the peak at 1580 cm ⁻¹ is 24.5 cm. ^-1 . Also, the (002) plane spacing by XRD diffraction was 3.36 mm.

[Comparative Example 1]
Using the same equipment as in Example 1, the ratio of the peak intensity of 1350 cm ^-1 to the peak intensity of 1580 cm ^-1 in the argon laser Raman spectra of carbonaceous material obtained on 1500 ° C. heated and held in a quartz substrate surface as a comparative example but at 0.19, the half width at the peak of 1580 cm ^-1 was 20.3 cm ^-1. Also, the (002) plane spacing by XRD diffraction was 3.36 mm.

A lead wire is taken out from the carbonaceous material deposited on the quartz substrate and used as a working electrode 11, and further, metallic lithium is used as a counter electrode 12 and a reference electrode 13 in the test apparatus shown in FIG. A charge / discharge test was conducted in the voltage range of 4 V, and the initial capacity of the carbonaceous material was measured. In addition, a charge / discharge cycle test of 100 cycles was also performed. In addition, 1M-lithium hexafluorophosphate (LiPF ₆ ) and ethylene carbonate / dimethyl carbonate (1: 1) mixed electrolyte solution 14 were used for the electrolyte bath of the test apparatus.

  Table 1 shows the initial capacities and charge / discharge cycle test results of Examples 1 and 2 and Comparative Example. The charge / discharge cycle test result is expressed as a relative value with the capacity of Example 1 after 100 cycles as 100.

As shown in Table 1, a carbonaceous material in which the peak intensity ratio (I ₁₃₅₀ / I ₁₅₈₀ ) of two Raman bands and the half-value width of a Raman band of ₁₅₈₀ cm ⁻¹ are within a predetermined range is used as a positive electrode active material of a power storage device. As a result, it was found that both the initial capacity and the charge / discharge cycle performance were excellent.

  The present invention relates to various fields such as various mobile devices such as mobile phones and notebook computers, storage batteries for automobiles such as hybrid cars and electric cars, and storage batteries for power storage combined with new energy systems such as solar batteries and wind power generation. Can be widely used.

DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Positive electrode collector foil and external extraction electrode 3 Separator 4 Negative electrode 5 Negative electrode collector foil and external extraction electrode 6 Lithium metal 7 Lithium metal electrode extraction electrode 10 Power storage device 11 Working electrode 12 Counter electrode 13 Reference electrode 14 Electrolyte

Claims (9)

Carbonaceous material greater than the ratio 0.33 of the peak intensity of 1350 cm ^-1 to the peak intensity of 1580 cm ^-1 in the Raman spectrum, and the half width of 1580 cm ^-1 being greater than 22 cm ^-1.   2. The carbonaceous material according to claim 1, wherein the (002) plane spacing of the hexagonal graphite layer is 3.3 to 3.5 mm by X-ray diffraction.   The carbonaceous material according to claim 1, wherein the carbonaceous material is graphite.   An electrical storage device comprising the carbonaceous material according to claim 1 as an active material. A positive electrode comprising the carbonaceous material according to claim 1;
A negative electrode containing a carbonaceous material in which cations can be inserted and desorbed between layers, and
A power storage device filled with a non-aqueous electrolyte. The non-aqueous electrolyte is an electrolyte in which lithium ions are dissolved,
The negative electrode is a negative electrode containing a carbonaceous material capable of inserting and extracting lithium ions,
The electrical storage device according to claim 5, wherein the carbonaceous material included in the negative electrode is a material in which lithium ions are previously stored.   The power storage device according to claim 6, wherein the carbonaceous material included in the negative electrode is obtained by electrochemically reacting the negative electrode with lithium metal.   The electric storage device according to claim 6 or 7, wherein the potential of the negative electrode is 0.01 V or more and 0.25 V or less with respect to metallic lithium. The power storage device according to any one of claims 5 to 8, wherein the carbonaceous material included in the negative electrode is graphite or non-graphitizable carbon.

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