WO2021186765A1 - Internal temperature determination device and secondary battery system - Google Patents

Internal temperature determination device and secondary battery system Download PDF

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Publication number
WO2021186765A1
WO2021186765A1 PCT/JP2020/033322 JP2020033322W WO2021186765A1 WO 2021186765 A1 WO2021186765 A1 WO 2021186765A1 JP 2020033322 W JP2020033322 W JP 2020033322W WO 2021186765 A1 WO2021186765 A1 WO 2021186765A1
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Prior art keywords
internal temperature
secondary battery
resistance value
electrode
negative electrode
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PCT/JP2020/033322
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French (fr)
Japanese (ja)
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耕平 本蔵
渉太 伊藤
杉政　昌俊
誠之 廣岡
純 川治
栄二 關
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株式会社日立製作所
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Publication of WO2021186765A1 publication Critical patent/WO2021186765A1/en

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    • 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
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • 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
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • 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
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to an internal temperature determining device and a secondary battery system.
  • Patent Document 1 describes a lithium ion secondary battery including a positive electrode, a negative electrode, an electrolyte, and a third pole for replenishing at least one of the positive electrode and the negative electrode with lithium ions.
  • a lithium ion secondary battery comprising a material that releases Li +, wherein the potential of the material that releases Li + is 1.8 V or more based on Li / Li +.
  • the internal temperature of the lithium secondary battery can be measured.
  • a temperature sensor such as a thermoelectric pair
  • the installation of the temperature sensor is costly. Therefore, a new technology capable of determining the internal temperature of a lithium ion secondary battery is desired.
  • the problem to be solved by the present invention is to provide an internal temperature determining device and a secondary battery system capable of determining the internal temperature of a lithium ion secondary battery.
  • the internal temperature determining device of the present invention is arranged to face the positive electrode containing the positive electrode active material, the negative electrode containing the negative electrode active material, the positive electrode or the negative electrode, and lithium ions on at least one electrode of the positive electrode or the negative electrode.
  • An internal temperature determining device for a lithium ion secondary battery comprising a third electrode containing a lithium material that can be replenished with the third electrode, and the positive electrode active material or the positive electrode active material in the lithium material of the third electrode and the third electrode.
  • Inside the lithium ion secondary battery based on the resistance value between the electrodes arranged so that any of the negative electrode active materials faces each other, and the predetermined relationship between the resistance value and the internal temperature. It is provided with a temperature determining unit for determining the temperature.
  • Other solutions will be described later in the form for carrying out the invention.
  • an internal temperature determining device and a secondary battery system capable of determining the internal temperature of a lithium ion secondary battery.
  • FIG. 1 It is a schematic cross-sectional view which shows the secondary battery.
  • the secondary battery is shown, and is a schematic cross-sectional view in a direction different from FIG.
  • It is a schematic diagram which enlarged and shows the vicinity of a positive electrode, a negative electrode and a capacity recovery electrode.
  • It is a block diagram which shows the secondary battery system.
  • It is a figure which shows the relational expression as the relationship between the resistance value and the internal temperature in the charge state X1.
  • the present invention is not limited to the following contents and the illustrated contents, and can be arbitrarily modified and carried out within a range that does not significantly impair the effects of the present invention.
  • the present invention can be implemented by combining different embodiments. In the following description, the same members will be designated by the same reference numerals in different embodiments, and redundant description will be omitted.
  • FIG. 1 is a schematic cross-sectional view showing the secondary battery 100.
  • FIG. 2 shows the secondary battery 100, which is a schematic cross-sectional view in a direction different from that of FIG.
  • the secondary battery 100 may be any of a secondary battery cell, a battery module, or a battery pack.
  • the secondary battery 100 may include a plurality of cells.
  • the secondary battery 100 may be configured to include a plurality of battery modules including a plurality of cells.
  • the secondary battery 100 includes a positive electrode 11, a negative electrode 12, and a capacity recovery electrode 15 (third electrode. Electrode 1) arranged to face the positive electrode 11 or the negative electrode 12.
  • the secondary battery 100 includes a positive electrode terminal 2 connected to the positive electrode 11, a negative electrode terminal 3 connected to the negative electrode 12, and a capacitance recovery electrode terminal 4 (third electrode terminal) connected to the capacitance recovery electrode 15. ), The separator 5, and the exterior material 6.
  • a metal tab is connected to each of the current collecting foils 11a, 12a, 15a (see FIG. 3) of the positive electrode 11, the negative electrode 12, and the capacity recovery electrode 15.
  • the electrode 1, the separator 5, and the non-aqueous electrolytic solution (not shown) are sealed by the exterior material 6 so that only the tab portion is exposed to the outside of the exterior material 6 such as the laminated film.
  • the tabs become the positive electrode terminal 2, the negative electrode terminal 3, and the capacitance recovery electrode terminal 4 in FIG.
  • the positive electrode 11 and the negative electrode 12 are alternately arranged with the separator 5 interposed therebetween.
  • the capacitance recovery electrode 15 is arranged on the outermost side of the electrode 1.
  • a separator 5 is also arranged outside the capacitance recovery electrode 15.
  • a pair of negative electrodes 12 are arranged on the outermost side of the electrode group 20 including the positive electrodes 11 and the negative electrodes 12 arranged alternately.
  • the positive electrode 11 and the negative electrode 12 are alternately arranged via the separator 5.
  • a pair of capacitance recovery electrodes 15 are arranged outside the electrode group 20.
  • the electrode group 20 and the capacitance recovery electrode 15 are arranged via the separator 5.
  • the capacitance recovery electrode 15 may be arranged inside the electrode group 20 so as to face at least one of the positive electrode 11 and the negative electrode 12 in place of or in addition to the one arranged outside the electrode group 20.
  • the capacity recovery of the secondary battery 100 using the capacity recovery pole 15 will be described.
  • Capacity recovery is performed by replenishing the positive electrode 11 or the negative electrode 12 with lithium ions.
  • the lithium material 15b (FIG. 3) of the capacity recovery electrode 15 is the same as the positive electrode active material 11b (FIG. 3) of the positive electrode 11, the positive electrode 11 or the negative electrode 12 is connected to the capacity recovery electrode 15, and the capacity recovery electrode 15 is connected according to the electrode potential.
  • Lithium ions can be replenished to the positive electrode 11 or the negative electrode 12 by passing an appropriate current.
  • FIG. 3 is a schematic view showing the vicinity of the positive electrode 11, the negative electrode 12, and the capacity recovery electrode 15 in an enlarged manner.
  • the positive electrode 11 contains the positive electrode active material 11b, and the positive electrode active material 11b is supported on both sides of the current collector foil 11a (current collector, the same applies to other current collector foils).
  • the positive electrode active material is, for example, LiCoO 2, LiNi x Mn y Co z O 2.
  • the negative electrode 12 contains the negative electrode active material 12b, and the negative electrode active material 12b is supported on both surfaces of the current collecting foil 12a.
  • the negative electrode active material is, for example, graphite.
  • the capacity recovery electrode 15 contains a lithium material 15b capable of replenishing at least one electrode 1 of the positive electrode 11 or the negative electrode 12 with lithium ions, and the lithium material 15b is supported on both surfaces of the current collecting foil 15a.
  • Lithium material 15b is, for example, a positive electrode active material of LiCoO 2, etc. LiNi x Mn y Co z O 2 .
  • the lithium material 15b supported on the capacity recovery electrode 15 faces the negative electrode active material 12b supported on the negative electrode 12 arranged on the outermost side of the electrode group 20 via the separator 5.
  • the lithium material 15b faces the positive electrode active material 11b supported on the positive electrode 11 via the separator 5. Therefore, the capacity recovery electrode 15 and the electrode 1 which is either the positive electrode 11 or the negative electrode 12 are arranged so that either the positive electrode active material 11b or the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15. Will be done.
  • FIG. 4 is a block diagram showing the secondary battery system 200.
  • the secondary battery system 200 includes a secondary battery 100 and an internal temperature determining device 50 that determines the internal temperature of the secondary battery 100.
  • the internal temperature determining device 50 includes a charging state determining unit 51, a resistance value measuring unit 52, a temperature determining unit 53, and a database 54.
  • the charge state determination unit 51 determines the charge state of the secondary battery 100. By providing the charging state determining unit 51, when the relationship 54a changes depending on the charging state, an appropriate relationship 54a can be used according to the charging state.
  • the charge state of the secondary battery 100 can be calculated, for example, based on the remaining capacity with respect to the fully charged capacity.
  • the resistance value measuring unit 52 is between the capacitance recovery electrode 15 and the negative electrode 12 arranged so that the negative electrode active material 12b faces the lithium material 15b of the capacitance recovery electrode 15.
  • the resistance value (internal resistance) between the capacitance recovery electrode 15 and the negative electrode 12 is measured by energizing the current.
  • the electrode 1 facing the capacitance recovery electrode 15 may be a positive electrode 11 carrying a positive electrode active material 11b as described above, instead of the negative electrode active material 12b.
  • the significance of measuring the value will be explained.
  • the transfer of lithium ions is usually likely to occur between the opposite positive electrode active material 11b and the negative electrode active material 12b. Therefore, it can be said that the transfer of lithium ions is unlikely to occur in both the negative electrode active material 12b that does not face the positive electrode active material 11b and the positive electrode active material 11b that does not face the negative electrode active material 12b during charging and discharging.
  • One of the causes of deterioration of the secondary battery 100 due to charging / discharging is the fixation of lithium ions to other than the positive electrode active material 11b and the negative electrode active material 12b due to the transfer of lithium ions during charging / discharging. Therefore, it is considered that the positive electrode active material 11b and the negative electrode active material 12b, which are unlikely to exchange lithium ions during charging and discharging, are in a state close to the positive electrode active material 11b and the negative electrode active material 12b in the initial state (undegrade). ..
  • the capacity recovery using the capacity recovery pole 15 is performed when the battery capacity decreases as described above. Therefore, the frequency of capacity recovery is not high. Therefore, it is considered that the lithium material 15b contained in the capacity recovery electrode 15 is also in a state close to the lithium material 15b in the initial state.
  • the internal temperature determining device 50 does not face the capacity recovery electrode 15 and the positive electrode active material 11b, and the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15.
  • the resistance value between the negative electrode 12 arranged so as to be measured is measured. By doing so, it is possible to measure the resistance value between the capacitance recovery electrode 15 and the negative electrode 12 in a state close to the initial state. Therefore, although the details will be described later, the internal temperature of the secondary battery 100 can be determined based on the measured resistance value and the relationship between the predetermined resistance value and the internal temperature.
  • the resistance value between the capacitance recovery electrode 15 and the negative electrode 12 can be measured, for example, based on the principle of the 4-terminal method. Specifically, for example, a change in voltage caused by energization of a predetermined pulse current between the capacitance recovery electrode 15 and the negative electrode 12 can be measured, and a resistance value can be calculated based on the measured voltage value.
  • a plurality of positive electrodes 11, negative electrodes 12, and capacity recovery electrodes 15 are provided inside the exterior material 6. Then, the plurality of positive electrodes 11, the plurality of negative electrodes 12, and the plurality of capacitance recovery electrodes 15 are connected in parallel, respectively. Of these, a plurality of positive electrodes 11 are connected to the positive electrode terminals 2. The plurality of negative electrodes 12 are connected to the negative electrode terminals 3. The plurality of capacitance recovery poles 15 are connected to the capacitance recovery pole terminals 4. Therefore, when a current is passed between the capacitance recovery electrode terminal 4 and the negative electrode terminal 3, a current may flow between each of the capacitance recovery electrodes 15 and each of the negative electrodes 12.
  • the resistance is the smallest between the capacitance recovery electrode 15 and the negative electrode 12 installed at the shortest distance, and the current is most likely to flow.
  • the resistance of the negative electrode 12 facing the positive electrode 11 without facing the capacitance recovery electrode 15 is increased due to deterioration due to charging and discharging. Therefore, by passing a current between the capacitance recovery electrode terminal 4 and the negative electrode terminal 3, between the capacitance recovery electrode 15, which is the portion where the current is most likely to flow, and the negative electrode 12 facing the capacitance recovery electrode 15. It is thought that the most current flows through. Therefore, between the capacity recovery electrode 15 and the negative electrode 12 which is not opposed to the positive electrode active material 11b and is arranged so that the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15. Resistance value can be measured.
  • the resistance value measuring unit 52 measures the resistance value after a lapse of a predetermined time from the start of energization of the current between the capacitance recovery electrode 15 and the negative electrode 12 (the positive electrode 11 when the positive electrode 11 faces the capacitance recovery electrode 15). .. Since lithium ions are replenished from the capacity recovery electrode 15 to the negative electrode 12 by energization, the disturbance of the resistance value due to the replenishment of lithium ions can be alleviated by waiting for the resistance value measurement until a predetermined time elapses. Thereby, the measurement accuracy of the resistance value can be improved.
  • the predetermined time referred to here is a time during which the disturbance of the resistance value due to the replenishment of lithium ions from the capacitance recovery electrode 15 to the negative electrode 12 (the positive electrode 11 when the positive electrode 11 faces the capacitance recovery electrode 15) settles down.
  • the resistance value that appropriately reflects the internal temperature can be measured.
  • the specific time of the predetermined time can be determined by a preliminary experiment or the like using the secondary battery 100.
  • the temperature determination unit 53 of the secondary battery 100 is based on the resistance value measured by the resistance value measurement unit 52 and the relationship 54a between the predetermined resistance value and the internal temperature (FIGS. 5 to 7 described later). It determines the internal temperature.
  • the relationship 54a is stored in the database 54 in advance. The specific contents of the relationship 54a will be described with reference to FIGS. 5 to 7.
  • FIG. 5 is a diagram showing a relational expression as a relation 54a between the resistance value and the internal temperature in the charged state X1.
  • the relationship 54a is composed of a relational expression which is a mathematical expression in the example of FIG.
  • Relationship 54a is a relationship determined based on an experiment such as a preliminary experiment using the secondary battery 100, for example. Thereby, the internal resistance of the secondary battery 100 can be determined by using the resistance value measured in a state close to the initial state.
  • the horizontal axis is the logarithm of the internal temperature (measured value. Absolute temperature), and the vertical axis is the resistance value (measured value).
  • a linear relational expression can be obtained as the relational 54a.
  • FIG. 6 is a diagram showing a relational expression as a relation 54a between the resistance value and the internal temperature in the charged state Xn.
  • the charging state shown in FIG. 6 is different from the charging state X1 shown in FIG. 5 above.
  • the relationship 54a is also determined in the charging state Xn shown in FIG.
  • the relationship 54a between the resistance value and the internal temperature may change depending on the state of charge of the secondary battery 100. Therefore, in the illustrated example, the relationship 54a is determined for each state of charge (SOC) of the secondary battery 100. By using the relationship 54a determined for each charging state, the accuracy of determining the internal temperature can be improved.
  • the charging state is determined by the charging state determining unit 51 (FIG. 4) as described above.
  • the relationship 54a determined for each charging state can be determined, for example, by performing the above preliminary experiment by changing the charging state of the secondary battery 100 in the initial state.
  • FIG. 7 is a table showing the relationship 54a between the resistance value and the internal temperature determined for each charging state.
  • the resistance value is R1 at the temperature T1
  • the resistance value is R2 at the temperature T2
  • the resistance value is R3 at the temperature T3, and so on.
  • the relationship 54a is determined such that the resistance value Rm + 1 is determined at Rm and the temperature T2, and the resistance value Rm + 2 is determined at the temperature T3.
  • the charging state, internal temperature, and resistance value are not limited to those shown in the drawings.
  • the temperature determining unit 53 determines the relationship 54a corresponding to the charging state determined by the charging state determining unit 51, and based on the determined relationship 54a and the above resistance value, the secondary battery 100 Determine the internal temperature. That is, the temperature determination unit 53 first identifies the relationship 54a corresponding to the charge capacity determined by the charge state determination unit 51 from the relationship 54a stored in the database 54. Next, the temperature determination unit 53 determines the internal temperature corresponding to the resistance value measured by the resistance value measurement unit 52 based on the specified relationship 54a. If the relationship 54a is, for example, a relational expression, the temperature determination unit 53 calculates the internal temperature based on the relational expression. If the relationship 54a is, for example, a table, the temperature determination unit 53 reads the internal temperature corresponding to the resistance value from the table.
  • the determined internal temperature is output to, for example, a control device (not shown) of the secondary battery 100.
  • the control device uses the internal temperature to determine the characteristics of the secondary battery 100. The determined characteristics are used, for example, in charge / discharge control of the secondary battery 100.
  • the internal temperature determining device 50 is not shown, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), and an I / F (interface). ) Etc. are provided. Then, the internal temperature determining device 50 is embodied by executing a predetermined control program stored in the ROM by the CPU.
  • a CPU Central Processing Unit
  • RAM Random Access Memory
  • ROM Read Only Memory
  • HDD Hard Disk Drive
  • I / F interface
  • the internal temperature of the secondary battery 100 can be determined without installing a temperature sensor such as a thermoelectric pair. Therefore, the installation cost of the temperature sensor can be reduced. In addition, it is possible to reduce, for example, electrical wiring used when a temperature sensor is installed. In particular, these effects are more remarkable as the number of battery packs and the like constituting the secondary battery 100 increases.
  • the measured temperature may change depending on the location where the temperature sensor is installed.
  • the secondary battery 100 may be blown with air or the like to promote heat dissipation. Therefore, the measured temperature may change depending on whether the temperature sensor is installed at the air blowing place or at a portion far from the air blowing place.
  • the reliability of the determined internal temperature can be improved.
  • Electrode 100 Secondary battery 11 Positive electrode 11a Current collecting foil 11b Positive electrode active material 12 Negative electrode 12a Current collecting foil 12b Negative electrode active material 15 Capacity recovery electrode 15a Current collecting foil 15b Lithium material 2 Positive electrode terminal 20 Electrode group 200 Secondary battery system 3 Negative electrode Terminal 4 Capacity recovery electrode terminal 50 Internal temperature determination device 51 Charging state determination unit 52 Resistance value measurement unit 53 Temperature determination unit 54 Database 54a Relationship 6 Exterior material

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Abstract

Provided is an internal temperature determination device that can determine the internal temperature of a lithium ion secondary battery. An internal temperature determination device 50 of a secondary battery 100 comprises: a positive electrode containing a positive electrode active material; a negative electrode containing a negative electrode active material; and a third electrode that is disposed to face the positive electrode or the negative electrode and that contains a lithium material capable of supplementing the positive electrode and/or the negative electrode with lithium ions. The internal temperature determination device further comprises a temperature determination unit 53 for determining the internal temperature of the secondary battery 100 on the basis of: the resistance value between the third electrode and the electrode that is disposed such that the lithium material of the third electrode faces either the positive electrode active material or the negative electrode active material; and a predetermined relationship between the resistance value and the internal temperature.

Description

内部温度決定装置及び二次電池システムInternal temperature determination device and secondary battery system
　本発明は、内部温度決定装置及び二次電池システムに関する。 The present invention relates to an internal temperature determining device and a secondary battery system.
　リチウムイオン二次電池において充放電が繰り返されると、劣化により電池容量が減少する。そこで、電池容量の回復に関する技術が知られている。特許文献１には、正極と、負極と、電解質と、前記正極と前記負極との少なくともいずれかにリチウムイオンを補充する第三極を備えるリチウムイオン二次電池であって、前記第三極は、Ｌｉ+を放出する材料を含み、前記Ｌｉ+を放出する材料の電位はＬｉ／Ｌｉ+基準で１．８Ｖ以上であることを特徴とするリチウムイオン二次電池が記載されている。 When charging and discharging are repeated in a lithium-ion secondary battery, the battery capacity decreases due to deterioration. Therefore, a technique for recovering battery capacity is known. Patent Document 1 describes a lithium ion secondary battery including a positive electrode, a negative electrode, an electrolyte, and a third pole for replenishing at least one of the positive electrode and the negative electrode with lithium ions. , A lithium ion secondary battery comprising a material that releases Li +, wherein the potential of the material that releases Li + is 1.8 V or more based on Li / Li +.
特開２０１６－７６３５８号公報Japanese Unexamined Patent Publication No. 2016-76358
　リチウムイオン二次電池の特性はリチウムイオン二次電池の内部温度により変化する。このため、特許文献１に記載の技術において、リチウム二次電池の内部温度が測定され得る。内部温度の測定のため、例えばリチウムイオン二次電池の外装に熱電対等の温度センサを設置することが考えられる。しかし、温度センサの設置はコストがかかる。このため、リチウムイオン二次電池の内部温度を決定可能な新しい技術が望まれる。 The characteristics of the lithium-ion secondary battery change depending on the internal temperature of the lithium-ion secondary battery. Therefore, in the technique described in Patent Document 1, the internal temperature of the lithium secondary battery can be measured. For measuring the internal temperature, for example, it is conceivable to install a temperature sensor such as a thermoelectric pair on the exterior of the lithium ion secondary battery. However, the installation of the temperature sensor is costly. Therefore, a new technology capable of determining the internal temperature of a lithium ion secondary battery is desired.
　本発明が解決しようとする課題は、リチウムイオン二次電池の内部温度を決定可能な内部温度決定装置及び二次電池システムの提供である。 The problem to be solved by the present invention is to provide an internal temperature determining device and a secondary battery system capable of determining the internal temperature of a lithium ion secondary battery.
　本発明の内部温度決定装置は、正極活物質を含む正極と、負極活物質を含む負極と、前記正極又は前記負極に対向して配置され、前記正極又は前記負極の少なくとも一方の電極にリチウムイオンを補充可能なリチウム材料を含む第三極と、を備えるリチウムイオン二次電池の内部温度決定装置であって、前記第三極と、前記第三極の前記リチウム材料に前記正極活物質又は前記負極活物質の何れかが対向するように配置された前記電極と、の間の抵抗値、及び、予め定められた前記抵抗値と内部温度との関係に基づき、前記リチウムイオン二次電池の内部温度を決定する温度決定部を備える。その他の解決手段は発明を実施するための形態において後記する。 The internal temperature determining device of the present invention is arranged to face the positive electrode containing the positive electrode active material, the negative electrode containing the negative electrode active material, the positive electrode or the negative electrode, and lithium ions on at least one electrode of the positive electrode or the negative electrode. An internal temperature determining device for a lithium ion secondary battery comprising a third electrode containing a lithium material that can be replenished with the third electrode, and the positive electrode active material or the positive electrode active material in the lithium material of the third electrode and the third electrode. Inside the lithium ion secondary battery based on the resistance value between the electrodes arranged so that any of the negative electrode active materials faces each other, and the predetermined relationship between the resistance value and the internal temperature. It is provided with a temperature determining unit for determining the temperature. Other solutions will be described later in the form for carrying out the invention.
　本発明によれば、リチウムイオン二次電池の内部温度を決定可能な内部温度決定装置及び二次電池システムを提供できる。 According to the present invention, it is possible to provide an internal temperature determining device and a secondary battery system capable of determining the internal temperature of a lithium ion secondary battery.
二次電池を示す模式的な断面図である。It is a schematic cross-sectional view which shows the secondary battery. 二次電池を示し、図１とは異なる方向への模式的な断面図である。The secondary battery is shown, and is a schematic cross-sectional view in a direction different from FIG. 正極、負極及び容量回復極の近傍を拡大して示す模式図である。It is a schematic diagram which enlarged and shows the vicinity of a positive electrode, a negative electrode and a capacity recovery electrode. 二次電池システムを示すブロック図である。It is a block diagram which shows the secondary battery system. 充電状態Ｘ１における抵抗値と内部温度との関係としての関係式を示す図である。It is a figure which shows the relational expression as the relationship between the resistance value and the internal temperature in the charge state X1. 充電状態Ｘｎにおける抵抗値と内部温度との関係としての関係式を示す図である。It is a figure which shows the relational expression as the relationship between a resistance value and an internal temperature in a charge state Xn. 充電状態毎に定められた抵抗値と内部温度との関係を示す表である。It is a table which shows the relationship between the resistance value and the internal temperature determined for each charge state.
　以下、本発明を実施するための形態（本実施形態）を説明する。ただし、本発明は以下の内容及び図示の内容になんら限定されず、本発明の効果を著しく損なわない範囲で任意に変形して実施できる。本発明は、異なる実施形態同士を組み合わせて実施できる。以下の記載において、異なる実施形態において同じ部材については同じ符号を付し、重複する説明は省略する。 Hereinafter, a mode for carrying out the present invention (the present embodiment) will be described. However, the present invention is not limited to the following contents and the illustrated contents, and can be arbitrarily modified and carried out within a range that does not significantly impair the effects of the present invention. The present invention can be implemented by combining different embodiments. In the following description, the same members will be designated by the same reference numerals in different embodiments, and redundant description will be omitted.
　図１は、二次電池１００を示す模式的な断面図である。また、図２は、二次電池１００を示し、図１とは異なる方向への模式的な断面図である。本明細書において、二次電池１００は、二次電池のセル、電池モジュール又は電池パックのいずれでもよい。例えば、二次電池１００は、複数個のセルを含むものであってもよい。また、二次電池１００は、複数個のセルを含む電池モジュールを複数個含む構成であってもよい。 FIG. 1 is a schematic cross-sectional view showing the secondary battery 100. Further, FIG. 2 shows the secondary battery 100, which is a schematic cross-sectional view in a direction different from that of FIG. In the present specification, the secondary battery 100 may be any of a secondary battery cell, a battery module, or a battery pack. For example, the secondary battery 100 may include a plurality of cells. Further, the secondary battery 100 may be configured to include a plurality of battery modules including a plurality of cells.
　二次電池１００は、正極１１と、負極１２と、正極１１又は負極１２に対向して配置された容量回復極１５（第三極。電極１）とを備えるものである。他にも、二次電池１００は、正極１１に接続された正極端子２と、負極１２に接続された負極端子３と、容量回復極１５に接続された容量回復極端子４（第三極端子）と、セパレータ５と、外装材６と、を備える。 The secondary battery 100 includes a positive electrode 11, a negative electrode 12, and a capacity recovery electrode 15 (third electrode. Electrode 1) arranged to face the positive electrode 11 or the negative electrode 12. In addition, the secondary battery 100 includes a positive electrode terminal 2 connected to the positive electrode 11, a negative electrode terminal 3 connected to the negative electrode 12, and a capacitance recovery electrode terminal 4 (third electrode terminal) connected to the capacitance recovery electrode 15. ), The separator 5, and the exterior material 6.
　正極１１、負極１２及び容量回復極１５の各集電箔１１ａ，１２ａ，１５ａ（いずれも図３参照）には、金属のタブが接続されている。タブ部分だけがラミネートフィルム等の外装材６の外部に露出するように、電極１、セパレータ５及び非水電解液（図示しない）が外装材６により封止される。これにより、タブが図１の正極端子２、負極端子３及び容量回復極端子４となる。また、正極１１と負極１２とはセパレータ５を挟んで交互に配置される。容量回復極１５は、電極１としては最も外側に配置される。容量回復極１５の外側にも、セパレータ５が配置される。 A metal tab is connected to each of the current collecting foils 11a, 12a, 15a (see FIG. 3) of the positive electrode 11, the negative electrode 12, and the capacity recovery electrode 15. The electrode 1, the separator 5, and the non-aqueous electrolytic solution (not shown) are sealed by the exterior material 6 so that only the tab portion is exposed to the outside of the exterior material 6 such as the laminated film. As a result, the tabs become the positive electrode terminal 2, the negative electrode terminal 3, and the capacitance recovery electrode terminal 4 in FIG. Further, the positive electrode 11 and the negative electrode 12 are alternately arranged with the separator 5 interposed therebetween. The capacitance recovery electrode 15 is arranged on the outermost side of the electrode 1. A separator 5 is also arranged outside the capacitance recovery electrode 15.
　二次電池１００では、交互に配置された正極１１及び負極１２を含む電極群２０において最も外側に一対の負極１２が配置される。正極１１及び負極１２は、セパレータ５を介して交互に配置される。また、電極群２０の外側に一対の容量回復極１５が配置される。電極群２０と容量回復極１５とは、セパレータ５を介して配置される。なお、容量回復極１５は、電極群２０の外側に配置されたものに代えて又は加えて、正極１１又は負極１２の少なくとも一方と対向するように電極群２０の内部に配置されてもよい。 In the secondary battery 100, a pair of negative electrodes 12 are arranged on the outermost side of the electrode group 20 including the positive electrodes 11 and the negative electrodes 12 arranged alternately. The positive electrode 11 and the negative electrode 12 are alternately arranged via the separator 5. Further, a pair of capacitance recovery electrodes 15 are arranged outside the electrode group 20. The electrode group 20 and the capacitance recovery electrode 15 are arranged via the separator 5. The capacitance recovery electrode 15 may be arranged inside the electrode group 20 so as to face at least one of the positive electrode 11 and the negative electrode 12 in place of or in addition to the one arranged outside the electrode group 20.
　容量回復極１５を用いた二次電池１００の容量回復について説明する。二次電池１００の劣化により電池容量が低下した場合、二次電池１００の容量回復が行われる。容量回復は、正極１１又は負極１２へのリチウムイオンの補充によって行われる。容量回復極１５のリチウム材料１５ｂ（図３）が正極１１の正極活物質１１ｂ（図３）と同じである場合、正極１１又は負極１２と容量回復極１５とを接続し、電極電位に応じて適宜電流を流すことで、正極１１又は負極１２にリチウムイオンを補充できる。 The capacity recovery of the secondary battery 100 using the capacity recovery pole 15 will be described. When the battery capacity decreases due to the deterioration of the secondary battery 100, the capacity of the secondary battery 100 is restored. Capacity recovery is performed by replenishing the positive electrode 11 or the negative electrode 12 with lithium ions. When the lithium material 15b (FIG. 3) of the capacity recovery electrode 15 is the same as the positive electrode active material 11b (FIG. 3) of the positive electrode 11, the positive electrode 11 or the negative electrode 12 is connected to the capacity recovery electrode 15, and the capacity recovery electrode 15 is connected according to the electrode potential. Lithium ions can be replenished to the positive electrode 11 or the negative electrode 12 by passing an appropriate current.
　図３は、正極１１、負極１２及び容量回復極１５の近傍を拡大して示す模式図である。正極１１は正極活物質１１ｂを含み、正極活物質１１ｂは、集電箔１１ａ（集電体。他の集電箔についても同じ）の両面に担持される。正極活物質は例えばＬｉＣｏＯ２、ＬｉＮｉｘＭｎｙＣｏｚＯ２である。負極１２は負極活物質１２ｂを含み、負極活物質１２ｂは、集電箔１２ａの両面に担持される。負極活物質は例えば黒鉛である。 FIG. 3 is a schematic view showing the vicinity of the positive electrode 11, the negative electrode 12, and the capacity recovery electrode 15 in an enlarged manner. The positive electrode 11 contains the positive electrode active material 11b, and the positive electrode active material 11b is supported on both sides of the current collector foil 11a (current collector, the same applies to other current collector foils). The positive electrode active material is, for example, LiCoO 2, LiNi x Mn y Co z O 2. The negative electrode 12 contains the negative electrode active material 12b, and the negative electrode active material 12b is supported on both surfaces of the current collecting foil 12a. The negative electrode active material is, for example, graphite.
　容量回復極１５は、正極１１又は負極１２の少なくとも一方の電極１にリチウムイオンを補充可能なリチウム材料１５ｂを含み、リチウム材料１５ｂは、集電箔１５ａの両面に担持される。リチウム材料１５ｂは、例えば、ＬｉＣｏＯ２、ＬｉＮｉｘＭｎｙＣｏｚＯ２等の正極活物質である。 The capacity recovery electrode 15 contains a lithium material 15b capable of replenishing at least one electrode 1 of the positive electrode 11 or the negative electrode 12 with lithium ions, and the lithium material 15b is supported on both surfaces of the current collecting foil 15a. Lithium material 15b is, for example, a positive electrode active material of LiCoO 2, etc. LiNi x Mn y Co z O 2 .
　容量回復極１５に担持されたリチウム材料１５ｂは、セパレータ５を介して、電極群２０の最も外側に配置された負極１２に担持された負極活物質１２ｂと対向する。なお、電極群２０の最も外側に正極１１が配置される場合には、リチウム材料１５ｂは、セパレータ５を介して、正極１１に担持された正極活物質１１ｂと対向する。従って、容量回復極１５と、正極１１又は負極１２の何れかである電極１とは、容量回復極１５のリチウム材料１５ｂに正極活物質１１ｂ又は負極活物質１２ｂの何れかが対向するように配置される。 The lithium material 15b supported on the capacity recovery electrode 15 faces the negative electrode active material 12b supported on the negative electrode 12 arranged on the outermost side of the electrode group 20 via the separator 5. When the positive electrode 11 is arranged on the outermost side of the electrode group 20, the lithium material 15b faces the positive electrode active material 11b supported on the positive electrode 11 via the separator 5. Therefore, the capacity recovery electrode 15 and the electrode 1 which is either the positive electrode 11 or the negative electrode 12 are arranged so that either the positive electrode active material 11b or the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15. Will be done.
　図４は、二次電池システム２００を示すブロック図である。二次電池システム２００は、二次電池１００と、二次電池１００の内部温度を決定する内部温度決定装置５０とを備える。内部温度決定装置５０は、充電状態決定部５１と、抵抗値測定部５２と、温度決定部５３と、データベース５４とを備える。 FIG. 4 is a block diagram showing the secondary battery system 200. The secondary battery system 200 includes a secondary battery 100 and an internal temperature determining device 50 that determines the internal temperature of the secondary battery 100. The internal temperature determining device 50 includes a charging state determining unit 51, a resistance value measuring unit 52, a temperature determining unit 53, and a database 54.
　充電状態決定部５１は、二次電池１００の充電状態を決定するものである。充電状態決定部５１を備えることで、充電状態によって関係５４ａが変化する場合に、充電状態に応じて適切な関係５４ａを使用できる。 The charge state determination unit 51 determines the charge state of the secondary battery 100. By providing the charging state determining unit 51, when the relationship 54a changes depending on the charging state, an appropriate relationship 54a can be used according to the charging state.
　二次電池１００の充電状態は、例えば、満充電容量に対する残容量に基づいて算出できる。 The charge state of the secondary battery 100 can be calculated, for example, based on the remaining capacity with respect to the fully charged capacity.
　抵抗値測定部５２は、いずれも図３に示したが、容量回復極１５と、容量回復極１５のリチウム材料１５ｂに負極活物質１２ｂが対向するように配置された負極１２と、の間への電流の通電によって、容量回復極１５と負極１２との間の抵抗値（内部抵抗）を測定するものである。なお、容量回復極１５に対向する電極１は、負極活物質１２ｂに代えて、上記のように正極活物質１１ｂを担持した正極１１でもよい。抵抗値測定部５２を備えることで、二次電池１００の内部抵抗を測定できる。 The resistance value measuring unit 52, as shown in FIG. 3, is between the capacitance recovery electrode 15 and the negative electrode 12 arranged so that the negative electrode active material 12b faces the lithium material 15b of the capacitance recovery electrode 15. The resistance value (internal resistance) between the capacitance recovery electrode 15 and the negative electrode 12 is measured by energizing the current. The electrode 1 facing the capacitance recovery electrode 15 may be a positive electrode 11 carrying a positive electrode active material 11b as described above, instead of the negative electrode active material 12b. By providing the resistance value measuring unit 52, the internal resistance of the secondary battery 100 can be measured.
　ここで、容量回復極１５と、容量回復極１５のリチウム材料１５ｂ（図３）に正極活物質１１ｂ又は負極活物質１２ｂの何れかが対向するように配置された電極１と、の間の抵抗値を測定することの意義について説明する。二次電池１００の充放電の際、正極１１の正極活物質１１ｂと負極１２の負極活物質１２ｂとの間でリチウムイオンの授受が行われる。リチウムイオンの授受は、通常は、対向する正極活物質１１ｂと負極活物質１２ｂとの間で生じ易い。このため、正極活物質１１ｂとは対向しない負極活物質１２ｂ、及び、負極活物質１２ｂとは対向しない正極活物質１１ｂでは、いずれも、充放電時にリチウムイオンの授受は生じ難いといえる。 Here, the resistance between the capacitance recovery electrode 15 and the electrode 1 arranged so that either the positive electrode active material 11b or the negative electrode active material 12b faces the lithium material 15b (FIG. 3) of the capacitance recovery electrode 15. The significance of measuring the value will be explained. When the secondary battery 100 is charged and discharged, lithium ions are exchanged between the positive electrode active material 11b of the positive electrode 11 and the negative electrode active material 12b of the negative electrode 12. The transfer of lithium ions is usually likely to occur between the opposite positive electrode active material 11b and the negative electrode active material 12b. Therefore, it can be said that the transfer of lithium ions is unlikely to occur in both the negative electrode active material 12b that does not face the positive electrode active material 11b and the positive electrode active material 11b that does not face the negative electrode active material 12b during charging and discharging.
　充放電に伴う二次電池１００の劣化の要因の一つは、充放電時のリチウムイオンの授受に起因した、正極活物質１１ｂ及び負極活物質１２ｂ以外へのリチウムイオンの固定である。従って、充放電時にリチウムイオンの授受が生じ難い上記正極活物質１１ｂ及び負極活物質１２ｂは、初期状態（未劣化）の正極活物質１１ｂ及び負極活物質１２ｂに近い状態になっていると考えられる。 One of the causes of deterioration of the secondary battery 100 due to charging / discharging is the fixation of lithium ions to other than the positive electrode active material 11b and the negative electrode active material 12b due to the transfer of lithium ions during charging / discharging. Therefore, it is considered that the positive electrode active material 11b and the negative electrode active material 12b, which are unlikely to exchange lithium ions during charging and discharging, are in a state close to the positive electrode active material 11b and the negative electrode active material 12b in the initial state (undegrade). ..
　また、容量回復極１５を用いた容量回復は、上記のように電池容量の低下時に行われる。このため、容量回復の頻度は高くは無い。従って、容量回復極１５に含まれるリチウム材料１５ｂも、初期状態のリチウム材料１５ｂに近い状態になっていると考えられる。 Further, the capacity recovery using the capacity recovery pole 15 is performed when the battery capacity decreases as described above. Therefore, the frequency of capacity recovery is not high. Therefore, it is considered that the lithium material 15b contained in the capacity recovery electrode 15 is also in a state close to the lithium material 15b in the initial state.
　そこで、内部温度決定装置５０は、図示の例では、容量回復極１５と、正極活物質１１ｂとは対向しておらず、かつ、容量回復極１５のリチウム材料１５ｂに負極活物質１２ｂが対向するように配置された負極１２と、の間の抵抗値を測定する。このようにすることで、初期状態に近い状態における、容量回復極１５と負極１２との間の抵抗値を測定できる。このため、詳細は後記するが、測定された抵抗値と、予め定められた抵抗値と内部温度との関係とに基づくことで、二次電池１００の内部温度を決定できる。 Therefore, in the illustrated example, the internal temperature determining device 50 does not face the capacity recovery electrode 15 and the positive electrode active material 11b, and the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15. The resistance value between the negative electrode 12 arranged so as to be measured is measured. By doing so, it is possible to measure the resistance value between the capacitance recovery electrode 15 and the negative electrode 12 in a state close to the initial state. Therefore, although the details will be described later, the internal temperature of the secondary battery 100 can be determined based on the measured resistance value and the relationship between the predetermined resistance value and the internal temperature.
　容量回復極１５と負極１２との間の抵抗値の測定は、例えば、４端子法の原理に基づいて測定できる。具体的には、例えば、容量回復極１５と負極１２との間への所定のパルス電流の通電により生じる電圧の変化を測定し、測定された電圧値に基づいて抵抗値を算出できる。 The resistance value between the capacitance recovery electrode 15 and the negative electrode 12 can be measured, for example, based on the principle of the 4-terminal method. Specifically, for example, a change in voltage caused by energization of a predetermined pulse current between the capacitance recovery electrode 15 and the negative electrode 12 can be measured, and a resistance value can be calculated based on the measured voltage value.
　なお、図１及び図２に示す二次電池１００では、一例として、外装材６の内部において、正極１１、負極１２及び容量回復極１５はいずれも複数備えられる。そして、複数の正極１１、複数の負極１２及び複数の容量回復極１５は、それぞれ、並列に接続される。これらのうち、複数の正極１１は正極端子２に接続される。複数の負極１２は負極端子３に接続される。複数の容量回復極１５は容量回復極端子４に接続される。このため、容量回復極端子４と負極端子３との間に電流を流すと、各容量回復極１５のそれぞれと、各負極１２のそれぞれとの間で電流が流れる可能性がある。 In the secondary battery 100 shown in FIGS. 1 and 2, as an example, a plurality of positive electrodes 11, negative electrodes 12, and capacity recovery electrodes 15 are provided inside the exterior material 6. Then, the plurality of positive electrodes 11, the plurality of negative electrodes 12, and the plurality of capacitance recovery electrodes 15 are connected in parallel, respectively. Of these, a plurality of positive electrodes 11 are connected to the positive electrode terminals 2. The plurality of negative electrodes 12 are connected to the negative electrode terminals 3. The plurality of capacitance recovery poles 15 are connected to the capacitance recovery pole terminals 4. Therefore, when a current is passed between the capacitance recovery electrode terminal 4 and the negative electrode terminal 3, a current may flow between each of the capacitance recovery electrodes 15 and each of the negative electrodes 12.
　しかし、通常は、最も近距離に設置された容量回復極１５と負極１２との間で抵抗が最も小さく、電流が最も流れやすい。特に、容量回復極１５と対向せずに正極１１と対向した負極１２では、充放電に伴う劣化により抵抗が大きくなっていると考えられる。このため、容量回復極端子４と負極端子３との間に電流を流すことで、最も電流が流れ易い部分である、容量回復極１５と、当該容量回復極１５と対向する負極１２との間に電流が最も流れると考えられる。このため、容量回復極１５と、正極活物質１１ｂとは対向しておらず、かつ、容量回復極１５のリチウム材料１５ｂに負極活物質１２ｂが対向するように配置された負極１２と、の間の抵抗値を測定できる。 However, normally, the resistance is the smallest between the capacitance recovery electrode 15 and the negative electrode 12 installed at the shortest distance, and the current is most likely to flow. In particular, it is considered that the resistance of the negative electrode 12 facing the positive electrode 11 without facing the capacitance recovery electrode 15 is increased due to deterioration due to charging and discharging. Therefore, by passing a current between the capacitance recovery electrode terminal 4 and the negative electrode terminal 3, between the capacitance recovery electrode 15, which is the portion where the current is most likely to flow, and the negative electrode 12 facing the capacitance recovery electrode 15. It is thought that the most current flows through. Therefore, between the capacity recovery electrode 15 and the negative electrode 12 which is not opposed to the positive electrode active material 11b and is arranged so that the negative electrode active material 12b faces the lithium material 15b of the capacity recovery electrode 15. Resistance value can be measured.
　抵抗値測定部５２は、容量回復極１５と負極１２（容量回復極１５に正極１１が対向する場合には正極１１）との間への電流の通電開始から所定時間経過後に抵抗値を測定する。通電により容量回復極１５から負極１２にリチウムイオンが補充されるため、所定時間経過まで抵抗値測定を待つことで、リチウムイオンの補充に起因する抵抗値の乱れを緩和できる。これにより、抵抗値の測定精度を向上できる。 The resistance value measuring unit 52 measures the resistance value after a lapse of a predetermined time from the start of energization of the current between the capacitance recovery electrode 15 and the negative electrode 12 (the positive electrode 11 when the positive electrode 11 faces the capacitance recovery electrode 15). .. Since lithium ions are replenished from the capacity recovery electrode 15 to the negative electrode 12 by energization, the disturbance of the resistance value due to the replenishment of lithium ions can be alleviated by waiting for the resistance value measurement until a predetermined time elapses. Thereby, the measurement accuracy of the resistance value can be improved.
　ここでいう所定時間は、容量回復極１５から負極１２（容量回復極１５に正極１１が対向する場合には正極１１）へのリチウムイオンの補充に起因する抵抗値の乱れが落ち着く時間である。抵抗値の乱れが落ち着く所定時間が経過してから抵抗値を測定することで、内部温度を適切に反映した抵抗値を測定できる。所定時間の具体的な時間は、二次電池１００を用いた予備実験等により決定できる。 The predetermined time referred to here is a time during which the disturbance of the resistance value due to the replenishment of lithium ions from the capacitance recovery electrode 15 to the negative electrode 12 (the positive electrode 11 when the positive electrode 11 faces the capacitance recovery electrode 15) settles down. By measuring the resistance value after a predetermined time has elapsed for the disturbance of the resistance value to settle down, the resistance value that appropriately reflects the internal temperature can be measured. The specific time of the predetermined time can be determined by a preliminary experiment or the like using the secondary battery 100.
　温度決定部５３は、抵抗値測定部５２により測定された抵抗値、及び、予め定められた抵抗値と内部温度との関係５４ａ（後記する図５～図７）に基づき、二次電池１００の内部温度を決定するものである。関係５４ａはデータベース５４に予め記憶されている。関係５４ａの具体的内容について、図５～図７を参照して説明する。 The temperature determination unit 53 of the secondary battery 100 is based on the resistance value measured by the resistance value measurement unit 52 and the relationship 54a between the predetermined resistance value and the internal temperature (FIGS. 5 to 7 described later). It determines the internal temperature. The relationship 54a is stored in the database 54 in advance. The specific contents of the relationship 54a will be described with reference to FIGS. 5 to 7.
　図５は、充電状態Ｘ１における抵抗値と内部温度との関係５４ａとしての関係式を示す図である。関係５４ａは、図５の例では数式である関係式により構成される。 FIG. 5 is a diagram showing a relational expression as a relation 54a between the resistance value and the internal temperature in the charged state X1. The relationship 54a is composed of a relational expression which is a mathematical expression in the example of FIG.
　関係５４ａは、例えば、二次電池１００を用いた予備実験等の実験に基づき決定された関係である。これにより、初期状態に近い状態で測定された抵抗値を用いて、二次電池１００の内部抵抗を決定できる。図５に示す例では、例えば、横軸を内部温度（実測値。絶対温度）の対数、縦軸を抵抗値（実測値）とし、二次電池１００を用いた予備実験により得られた結果をプロットすることで、関係５４ａとして例えば直線状の関係式が得られる。 Relationship 54a is a relationship determined based on an experiment such as a preliminary experiment using the secondary battery 100, for example. Thereby, the internal resistance of the secondary battery 100 can be determined by using the resistance value measured in a state close to the initial state. In the example shown in FIG. 5, for example, the horizontal axis is the logarithm of the internal temperature (measured value. Absolute temperature), and the vertical axis is the resistance value (measured value). By plotting, for example, a linear relational expression can be obtained as the relational 54a.
　図６は、充電状態Ｘｎにおける抵抗値と内部温度との関係５４ａとしての関係式を示す図である。図６に示す充電状態は、上記の図５に示す充電状態Ｘ１とは異なる。図６に示す充電状態Ｘｎにおいても関係５４ａが決定されている。 FIG. 6 is a diagram showing a relational expression as a relation 54a between the resistance value and the internal temperature in the charged state Xn. The charging state shown in FIG. 6 is different from the charging state X1 shown in FIG. 5 above. The relationship 54a is also determined in the charging state Xn shown in FIG.
　抵抗値との内部温度との関係５４ａは、二次電池１００の充電状態によって変わり得る。このため、図示の例では、関係５４ａは、二次電池１００の充電状態（ＳＯＣ）毎に決定されている。充電状態毎に決定された関係５４ａを用いることで、内部温度の決定精度を向上できる。なお、充電状態は、上記のように、充電状態決定部５１（図４）により決定される。 The relationship 54a between the resistance value and the internal temperature may change depending on the state of charge of the secondary battery 100. Therefore, in the illustrated example, the relationship 54a is determined for each state of charge (SOC) of the secondary battery 100. By using the relationship 54a determined for each charging state, the accuracy of determining the internal temperature can be improved. The charging state is determined by the charging state determining unit 51 (FIG. 4) as described above.
　充電状態毎に決定される関係５４ａは、例えば、初期状態における二次電池１００の充電状態を変えて上記の予備実験を行うことで、決定できる。 The relationship 54a determined for each charging state can be determined, for example, by performing the above preliminary experiment by changing the charging state of the secondary battery 100 in the initial state.
　図７は、充電状態毎に定められた抵抗値と内部温度との関係５４ａを示す表である。図７に示す例では、充電状態が例えばＸ１のとき、温度Ｔ１で抵抗値Ｒ１、温度Ｔ２で抵抗値Ｒ２、温度Ｔ３で抵抗値Ｒ３…、充電状態が例えばＸｎのとき、温度Ｔ１で抵抗値Ｒｍ、温度Ｔ２で抵抗値Ｒｍ＋１、温度Ｔ３で抵抗値Ｒｍ＋２のように関係５４ａが決定されている。なお、充電状態、内部温度及び抵抗値は、図示の内容に何ら限定されない。 FIG. 7 is a table showing the relationship 54a between the resistance value and the internal temperature determined for each charging state. In the example shown in FIG. 7, when the charging state is, for example, X1, the resistance value is R1 at the temperature T1, the resistance value is R2 at the temperature T2, the resistance value is R3 at the temperature T3, and so on. The relationship 54a is determined such that the resistance value Rm + 1 is determined at Rm and the temperature T2, and the resistance value Rm + 2 is determined at the temperature T3. The charging state, internal temperature, and resistance value are not limited to those shown in the drawings.
　図４に戻って、温度決定部５３は、充電状態決定部５１により決定された充電状態に対応する関係５４ａを決定し、決定した関係５４ａと上記の抵抗値とに基づき、二次電池１００の内部温度を決定する。即ち、温度決定部５３は、まず、充電状態決定部５１により決定された充電容量に対応する関係５４ａを、データベース５４に記憶された関係５４ａの中から特定する。次いで、温度決定部５３は、抵抗値測定部５２により測定された抵抗値に対応する内部温度を、当該特定した関係５４ａに基づき決定する。関係５４ａが例えば関係式であれば、温度決定部５３は当該関係式に基づき内部温度を算出する。関係５４ａが例えば表であれば、温度決定部５３は、抵抗値に対応する内部温度を当該表から読み取る。 Returning to FIG. 4, the temperature determining unit 53 determines the relationship 54a corresponding to the charging state determined by the charging state determining unit 51, and based on the determined relationship 54a and the above resistance value, the secondary battery 100 Determine the internal temperature. That is, the temperature determination unit 53 first identifies the relationship 54a corresponding to the charge capacity determined by the charge state determination unit 51 from the relationship 54a stored in the database 54. Next, the temperature determination unit 53 determines the internal temperature corresponding to the resistance value measured by the resistance value measurement unit 52 based on the specified relationship 54a. If the relationship 54a is, for example, a relational expression, the temperature determination unit 53 calculates the internal temperature based on the relational expression. If the relationship 54a is, for example, a table, the temperature determination unit 53 reads the internal temperature corresponding to the resistance value from the table.
　決定された内部温度は、例えば、二次電池１００の制御装置（図示しない）に出力される。制御装置は、内部温度を用いて二次電池１００の特性を決定する。決定された特性は、例えば、二次電池１００の充放電制御に使用される。 The determined internal temperature is output to, for example, a control device (not shown) of the secondary battery 100. The control device uses the internal temperature to determine the characteristics of the secondary battery 100. The determined characteristics are used, for example, in charge / discharge control of the secondary battery 100.
　なお、内部温度決定装置５０は、いずれも図示はしないが、例えばＣＰＵ（Central Processing Unit）、ＲＡＭ（Random Access Memory）、ＲＯＭ（Read Only Memory）、ＨＤＤ（Hard Disk Drive）、Ｉ／Ｆ（インターフェイス）等を備えて構成される。そして、内部温度決定装置５０は、ＲＯＭに格納されている所定の制御プログラムがＣＰＵによって実行されることにより具現化される。 Although the internal temperature determining device 50 is not shown, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), and an I / F (interface). ) Etc. are provided. Then, the internal temperature determining device 50 is embodied by executing a predetermined control program stored in the ROM by the CPU.
　内部温度決定装置５０によれば、熱電対等の温度センサを設置することなく、二次電池１００の内部温度を決定できる。このため、温度センサの設置コストを削減できる。また、温度センサを設置した場合に使用される例えば電気配線を削減できる。特に、これらの効果は、二次電池１００を構成する電池パック等の数が多くなるほど顕著である。 According to the internal temperature determining device 50, the internal temperature of the secondary battery 100 can be determined without installing a temperature sensor such as a thermoelectric pair. Therefore, the installation cost of the temperature sensor can be reduced. In addition, it is possible to reduce, for example, electrical wiring used when a temperature sensor is installed. In particular, these effects are more remarkable as the number of battery packs and the like constituting the secondary battery 100 increases.
　また、温度センサを設置する場合、温度センサの設置場所によって測定される温度が変化し得る。例えば、二次電池１００には、放熱促進のため空気等が吹き付けられることがある。このため、空気の吹き付け場所に温度センサが設置された場合と、空気の吹き付け場所から遠い部分に温度センサが設置された場合とで、測定される温度が変化し得る。しかし、温度センサを用いずに内部温度を決定することで、決定された内部温度の信頼性を向上できる。 Also, when installing a temperature sensor, the measured temperature may change depending on the location where the temperature sensor is installed. For example, the secondary battery 100 may be blown with air or the like to promote heat dissipation. Therefore, the measured temperature may change depending on whether the temperature sensor is installed at the air blowing place or at a portion far from the air blowing place. However, by determining the internal temperature without using the temperature sensor, the reliability of the determined internal temperature can be improved.
１　電極
１００　二次電池
１１　正極
１１ａ　集電箔
１１ｂ　正極活物質
１２　負極
１２ａ　集電箔
１２ｂ　負極活物質
１５　容量回復極
１５ａ　集電箔
１５ｂ　リチウム材料
２　正極端子
２０　電極群
２００　二次電池システム
３　負極端子
４　容量回復極端子
５０　内部温度決定装置
５１　充電状態決定部
５２　抵抗値測定部
５３　温度決定部
５４　データベース
５４ａ　関係
６　外装材 1 Electrode 100 Secondary battery 11 Positive electrode 11a Current collecting foil 11b Positive electrode active material 12 Negative electrode 12a Current collecting foil 12b Negative electrode active material 15 Capacity recovery electrode 15a Current collecting foil 15b Lithium material 2 Positive electrode terminal 20 Electrode group 200 Secondary battery system 3 Negative electrode Terminal 4 Capacity recovery electrode terminal 50 Internal temperature determination device 51 Charging state determination unit 52 Resistance value measurement unit 53 Temperature determination unit 54 Database 54a Relationship 6 Exterior material

Claims (9)

  1. 　正極活物質を含む正極と、負極活物質を含む負極と、前記正極又は前記負極に対向して配置され、前記正極又は前記負極の少なくとも一方の電極にリチウムイオンを補充可能なリチウム材料を含む第三極と、を備えるリチウムイオン二次電池の内部温度決定装置であって、
    　前記第三極と、前記第三極の前記リチウム材料に前記正極活物質又は前記負極活物質の何れかが対向するように配置された前記電極と、の間の抵抗値、及び、予め定められた前記抵抗値と内部温度との関係に基づき、前記リチウムイオン二次電池の内部温度を決定する温度決定部を備える
    　ことを特徴とする内部温度決定装置。     A positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and a lithium material arranged to face the positive electrode or the negative electrode and capable of replenishing at least one electrode of the positive electrode or the negative electrode with lithium ions. An internal temperature determining device for a lithium ion secondary battery equipped with three electrodes.
    A resistance value between the third pole and the electrode arranged so that either the positive electrode active material or the negative electrode active material faces the lithium material of the third pole, and a predetermined resistance value. An internal temperature determining device including a temperature determining unit that determines the internal temperature of the lithium ion secondary battery based on the relationship between the resistance value and the internal temperature.
  2. 　前記リチウムイオン二次電池の充電状態を決定する充電状態決定部を備える
    　ことを特徴とする請求項１に記載の内部温度決定装置。     The internal temperature determining device according to claim 1, further comprising a charging state determining unit that determines the charging state of the lithium ion secondary battery.
  3. 　前記関係は、前記リチウムイオン二次電池の充電状態毎に決定されている
    　ことを特徴とする請求項２に記載の内部温度決定装置。     The internal temperature determining device according to claim 2, wherein the relationship is determined for each charging state of the lithium ion secondary battery.
  4. 　前記温度決定部は、前記充電状態決定部により決定された充電状態に対応する前記関係を決定し、決定した前記関係と前記抵抗値とに基づき、前記リチウムイオン二次電池の内部温度を決定する
    　ことを特徴とする請求項３に記載の内部温度決定装置。     The temperature determining unit determines the relationship corresponding to the charging state determined by the charging state determining unit, and determines the internal temperature of the lithium ion secondary battery based on the determined relationship and the resistance value. The internal temperature determining device according to claim 3.
  5. 　前記第三極と前記電極との間への電流の通電によって前記抵抗値を測定する抵抗値測定部を備える
    　ことを特徴とする請求項１又は２に記載の内部温度決定装置。     The internal temperature determining device according to claim 1 or 2, further comprising a resistance value measuring unit that measures the resistance value by energizing a current between the third pole and the electrode.
  6. 　前記抵抗値測定部は、前記電流の通電開始から所定時間経過後に前記抵抗値を測定する
    　ことを特徴とする請求項５に記載の内部温度決定装置。     The internal temperature determining device according to claim 5, wherein the resistance value measuring unit measures the resistance value after a lapse of a predetermined time from the start of energization of the current.
  7. 　前記所定時間は、前記第三極から前記電極への前記リチウムイオンの補充に起因する前記抵抗値の乱れが落ち着く時間である
    　ことを特徴とする請求項６に記載の内部温度決定装置。     The internal temperature determining device according to claim 6, wherein the predetermined time is a time during which the disturbance of the resistance value due to the replenishment of the lithium ion from the third electrode to the electrode is settled.
  8. 　前記関係は実験に基づき決定された関係である
    　ことを特徴とする請求項１又は２に記載の内部温度決定装置。     The internal temperature determining device according to claim 1 or 2, wherein the relationship is determined based on an experiment.
  9. 　正極活物質を含む正極と、負極活物質を含む負極と、前記正極又は前記負極に対向して配置され、前記正極又は前記負極の少なくとも一方の電極にリチウムイオンを補充可能なリチウム材料を含む第三極と、を備えるリチウムイオン二次電池と、
    　前記第三極と、前記第三極の前記リチウム材料に前記正極活物質又は前記負極活物質の何れかが対向するように配置された前記電極と、の間の抵抗値、及び、予め定められた前記抵抗値と内部温度との関係に基づき、前記リチウムイオン二次電池の内部温度を決定する温度決定部を備える内部温度決定装置と、を備える
    　ことを特徴とする、二次電池システム。     A positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and a lithium material arranged to face the positive electrode or the negative electrode and capable of replenishing at least one electrode of the positive electrode or the negative electrode with lithium ions. Lithium-ion secondary battery with three poles,
    A resistance value between the third pole and the electrode arranged so that either the positive electrode active material or the negative electrode active material faces the lithium material of the third pole, and a predetermined resistance value. A secondary battery system comprising: an internal temperature determining device including a temperature determining unit for determining the internal temperature of the lithium ion secondary battery based on the relationship between the resistance value and the internal temperature.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010135075A (en) * 2008-12-02 2010-06-17 Calsonic Kansei Corp Method and device for estimating temperature of battery pack
JP2016051570A (en) * 2014-08-29 2016-04-11 株式会社日立製作所 Lithium ion battery system
JP2016091613A (en) * 2014-10-30 2016-05-23 株式会社日立製作所 Battery system and soc recovery method
JP2017091923A (en) * 2015-11-13 2017-05-25 トヨタ自動車株式会社 Capacity recovery method for lithium ion secondary battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010135075A (en) * 2008-12-02 2010-06-17 Calsonic Kansei Corp Method and device for estimating temperature of battery pack
JP2016051570A (en) * 2014-08-29 2016-04-11 株式会社日立製作所 Lithium ion battery system
JP2016091613A (en) * 2014-10-30 2016-05-23 株式会社日立製作所 Battery system and soc recovery method
JP2017091923A (en) * 2015-11-13 2017-05-25 トヨタ自動車株式会社 Capacity recovery method for lithium ion secondary battery

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