JP7063455B2 - Diagnostic device and diagnostic method for secondary batteries - Google Patents

Diagnostic device and diagnostic method for secondary batteries Download PDF

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JP7063455B2
JP7063455B2 JP2018073658A JP2018073658A JP7063455B2 JP 7063455 B2 JP7063455 B2 JP 7063455B2 JP 2018073658 A JP2018073658 A JP 2018073658A JP 2018073658 A JP2018073658 A JP 2018073658A JP 7063455 B2 JP7063455 B2 JP 7063455B2
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secondary battery
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reversible capacity
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JP2019185969A (en
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慶紀 成岡
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3Dom Inc
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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
    • H01M10/42—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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/392—Determining battery ageing or deterioration, e.g. state of health
    • 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
    • H01M10/04—Construction or manufacture in general
    • 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

Description

本発明は、再充電可能な二次電池に関し、更に特定的には、二次電池の状態を診断すること、およびその診断に基づいて、二次電池の寿命を予測すること、および二次電池を良好な状態に保つことに関する。 The present invention relates to a rechargeable secondary battery, and more specifically, to diagnose the state of the secondary battery, and to predict the life of the secondary battery based on the diagnosis, and the secondary battery. Regarding keeping the battery in good condition.

再充電可能な二次電池（以下、単に二次電池という）は、民生用の電源として広く用いられている。近年の電気自動車やロードレベリングなどで使用する二次電池では、長期にわたって使用できること、即ち、長い寿命を有することが要求されている。また、二次電池を長期にわたって使用する場合には、その寿命を予測することも極めて重要となっている。 Rechargeable secondary batteries (hereinafter simply referred to as secondary batteries) are widely used as a consumer power source. Secondary batteries used in recent electric vehicles and road leveling are required to be usable for a long period of time, that is, to have a long life. In addition, when a secondary battery is used for a long period of time, it is extremely important to predict its life.

二次電池では、累積使用期間（または累積充放電サイクル回数）の増加に伴って極（正極、負極）が劣化し、極の劣化に伴って可逆容量が低下することが知られている。 It is known that in a secondary battery, the poles (positive electrode and negative electrode) deteriorate as the cumulative usage period (or the number of cumulative charge / discharge cycles) increases, and the reversible capacity decreases as the poles deteriorate.

なお、可逆容量とは、所定の充電終止電圧と放電終止電圧との間で充放電できる容量、即ち、二次電池の容量のうちの実際に使用可能な容量である。また、可逆容量と関連する不可逆容量があるが、これは、二次電池の容量のうちの出力不可能な容量である。 The reversible capacity is a capacity that can be charged and discharged between a predetermined charge termination voltage and a discharge termination voltage, that is, a capacity that can actually be used among the capacities of the secondary battery. There is also an irreversible capacity associated with the reversible capacity, which is the unoutputtable capacity of the secondary battery capacity.

特開２００３－１７８８１２号公報（特許文献１）には、リチウム二次電池を評価する技術に関連する発明が開示されている。特許文献１に記載の発明では、「所定時間後のリチウム二次電池の容量（Ｑt）を所定の式に従って算出することにより、リチウム二次電池の寿命特性を評価する」という技術を用いる。簡単に説明すると、特許文献１に記載の発明では、リチウム二次電池の寿命の始まり（リチウム二次電池の使用開始時）からの累積使用期間に比例してリチウム二次電池の再充電可能な容量（可逆容量）が低下していくと想定し、寿命の始まりからの累積使用期間と可逆容量との間の直線則的な比例関係を用いて、リチウム二次電池の可逆容量の低下を予測している。 Japanese Unexamined Patent Publication No. 2003-178812 (Patent Document 1) discloses an invention related to a technique for evaluating a lithium secondary battery. In the invention described in Patent Document 1, a technique of "evaluating the life characteristics of a lithium secondary battery by calculating the capacity (Qt) of the lithium secondary battery after a predetermined time according to a predetermined formula" is used. Briefly, in the invention described in Patent Document 1, the lithium secondary battery can be recharged in proportion to the cumulative usage period from the beginning of the life of the lithium secondary battery (at the start of use of the lithium secondary battery). Assuming that the capacity (reversible capacity) is decreasing, the decrease in the reversible capacity of the lithium secondary battery is predicted by using the linear proportional relationship between the cumulative usage period from the beginning of the life and the reversible capacity. are doing.

「GS Yuasa Technical Report」の第５巻第１号（２００８年６月２７日発行）（非特許文献１）の第２１～２６ページにも、リチウムイオン電池の可逆容量の低下を予測する技術が開示されている。その技術では、リチウムイオン電池の寿命の始まり（リチウム二次電池の使用開始時）からの累積使用期間の経過と共にリチウムイオン電池の容量（可逆容量）がルート則に従って緩やかに低下していくと想定し、寿命の始まりからの累積使用期間と可逆容量との間のルート則的な比例関係を用いて、リチウムイオン電池の可逆容量の低下を予測している。 On pages 21-26 of "GS Yuasa Technical Report", Vol. 5, No. 1 (issued on June 27, 2008) (Non-Patent Document 1), there is a technique for predicting a decrease in the reversible capacity of a lithium-ion battery. It has been disclosed. With that technology, it is assumed that the capacity (reversible capacity) of a lithium-ion battery gradually decreases according to the root rule as the cumulative usage period elapses from the beginning of the life of the lithium-ion battery (at the start of use of the lithium secondary battery). However, the root-law proportional relationship between the cumulative usage period from the beginning of the life and the reversible capacity is used to predict the decrease in the reversible capacity of the lithium-ion battery.

電池に関して、特許文献１ではリチウム二次電池と記載され、非特許文献１ではリチウムイオン電池と記載されているが、以下では、これらをリチウムイオン二次電池という。 Regarding the battery, Patent Document 1 describes it as a lithium secondary battery, and Non-Patent Document 1 describes it as a lithium ion battery, but in the following, these are referred to as lithium ion secondary batteries.

特許文献１および非特許文献１に記載の技術は、双方とも、リチウムイオン二次電池の寿命の始めから終わりまでの累積使用期間と可逆容量との間に比例的な関係があることを前提としている。 Both the techniques described in Patent Document 1 and Non-Patent Document 1 are based on the premise that there is a proportional relationship between the cumulative usage period from the beginning to the end of the life of a lithium ion secondary battery and the reversible capacity. There is.

特開２０１７－０５４６９２号公報（特許文献２）には、二次電池（リチウムイオン二次電池）を用いた蓄電システムに関する発明が開示されている。特許文献２には、正極の劣化状態を示す尺度および負極の劣化状態を示す尺度を検出する技術が開示されており、請求項１には、「前記二次電池の制御システムは、正極の劣化状態を示す尺度を検出する手段と、負極の劣化状態を示す尺度を検出する手段と、前記正極の前記尺度と前記負極の前記尺度との差を計算する手段と、前記差の符号を判別する手段と、前記符号に応じて前記二次電池の動作条件を変更する手段と、を有する」という記載がある。 Japanese Unexamined Patent Publication No. 2017-054692 (Patent Document 2) discloses an invention relating to a power storage system using a secondary battery (lithium ion secondary battery). Patent Document 2 discloses a technique for detecting a scale indicating a deterioration state of a positive electrode and a scale indicating a deterioration state of a negative electrode, and in claim 1, "the control system of the secondary battery is a deterioration of the positive electrode. The means for detecting the scale indicating the state, the means for detecting the scale indicating the deterioration state of the negative electrode, the means for calculating the difference between the scale of the positive electrode and the scale of the negative electrode, and the sign of the difference are discriminated. It has means and means for changing the operating conditions of the secondary battery according to the reference numeral. "

上記の技術に関して、特許文献２の段落００２９には「本発明者は、この電池容量低下のメカニズムにおいて、劣化後の正極容量ＱＰと劣化後の負極容量ＱＮとが逆転することが、急激な電池特性低下の原因であることを突き止め、その結果、想定寿命よりもより短期間で電池の性能が著しく低下する現象が起こることを見出した。」との、また、段落００３１には、「なお、これらの尺度を監視するためには、劣化後の正極電位曲線ＶＰ及び劣化後の正極電位曲線ＶＮの計測又は算出をする手段が必要となる。これについては、二次電池に正極及び負極以外の第三極を挿入して、正極及び負極の電位を計測する手段を用いることや、劣化後の電池電圧ＶＢ、初期の正極電位曲線ＶＰ０及び初期の負極電位曲線ＶＮ０から劣化後の電池電圧を算出する手段等、公知の技術を用いることができる。なお、初期の正極電位曲線ＶＰ０及び初期の負極電位曲線ＶＮ０は、それぞれ、正極又は負極、あるいは単極で充放電を実施し、あらかじめ取得しておく。」という記載がある。即ち、特許文献２に記載の技術では、劣化後の正極容量と劣化後の負極容量とが逆転することを検出するために、正極および負極の劣化状態（電位）を、参照極を使用して測定するか、または充放電時の電池の電圧から推定する。 Regarding the above technique, paragraph 0029 of Patent Document 2 states, "In the mechanism of this battery capacity decrease, the present invention causes a sudden reversal of the deteriorated positive electrode capacity QP and the deteriorated negative electrode capacity QN. We found that it was the cause of the deterioration of the characteristics, and as a result, we found that the performance of the battery was significantly reduced in a shorter period than the expected life. " In order to monitor these scales, a means for measuring or calculating the deteriorated positive electrode potential curve VP and the deteriorated positive electrode potential curve VN is required. For this, the secondary battery other than the positive electrode and the negative electrode is required. By inserting a third pole and using a means to measure the potentials of the positive and negative electrodes, the deteriorated battery voltage is calculated from the deteriorated battery voltage VB, the initial positive electrode potential curve VP0 and the initial negative electrode potential curve VN0. A known technique can be used, such as means for charging and discharging the initial positive electrode potential curve VP0 and the initial negative electrode potential curve VN0, respectively. I will put it. " That is, in the technique described in Patent Document 2, in order to detect that the positive electrode capacity after deterioration and the negative electrode capacity after deterioration are reversed, the deterioration state (potential) of the positive electrode and the negative electrode is determined by using a reference electrode. Measure or estimate from the battery voltage during charging and discharging.

特開２００３－１７８８１２号公報Japanese Patent Application Laid-Open No. 2003-178812 特開２０１７－０５４６９２号公報Japanese Unexamined Patent Publication No. 2017-054692

GS Yuasa Technical Report（ＧＳユアサ テクニカルレポート）、第５巻第１号、２００８年６月２７日発行）、電気自動車用大形リチウムイオン電池「ＬＥＶ５０」とそのバッテリーモジュール「ＬＥＶ５０－４」の開発、北野真也その他、第２１ページ～第２６ページGS Yuasa Technical Report, Volume 5, Issue 1, June 27, 2008), Development of large lithium-ion battery "LEV50" for electric vehicles and its battery module "LEV50-4", Shinya Kitano and others, pages 21-26

特許文献１および非特許文献１に記載されているような従来技術では、リチウムイオン二次電池を長期にわたって使用する場合の可逆容量の低下の傾向を正確に予測できない欠点がある。その理由は、リチウムイオン二次電池の可逆容量の低下の原因は、負極の劣化と正極の劣化とを含むからである。より詳細には、リチウムイオン二次電池の可逆容量の低下は、負極の劣化が主な原因である場合と、正極の劣化が主な原因である場合とがあり、それぞれの場合によって可逆容量の低下の傾向が異なる。従って、寿命の始まり（ＢＯＬ、Beginning Of Life）から寿命の終わり（ＥＯＬ、End Of Life）までの累積使用期間と可逆容量との間に完全な比例的関係が成り立たないからである。 Conventional techniques such as those described in Patent Document 1 and Non-Patent Document 1 have a drawback that the tendency of a decrease in reversible capacity when a lithium ion secondary battery is used for a long period of time cannot be accurately predicted. The reason is that the cause of the decrease in the reversible capacity of the lithium ion secondary battery includes the deterioration of the negative electrode and the deterioration of the positive electrode. More specifically, the decrease in the reversible capacity of the lithium ion secondary battery may be mainly caused by the deterioration of the negative electrode or the deterioration of the positive electrode, and in each case, the reversible capacity of the reversible capacity is reduced. The tendency of decline is different. Therefore, there is no perfect proportional relationship between the cumulative usage period from the beginning of life (BOL, Beginning Of Life) to the end of life (EOL, End Of Life) and the reversible capacity.

より具体的には、リチウムイオン二次電池の正極と負極とのそれぞれの材料の構成にもよるが、一般に、リチウムイオン二次電池の使用開始時には、正極の不可逆容量が負極の不可逆容量よりも多い。また、負極の劣化（不可逆容量の増加）の速さは、正極の劣化（不可逆容量の増加）の速さよりも速い。従って、リチウムイオン二次電池の寿命の初期ないし中期には、正極の不可逆容量が負極の不可逆容量よりも多いが、或る時点（以下、移行点という）以降は、負極の不可逆容量が正極の不可逆容量よりも多くなる。即ち、リチウムイオン二次電池の可逆容量の低下は、寿命の初期ないし中期には、主に正極の不可逆容量と関連するが、移行点以降は、主に負極の不可逆容量と関連する。また、正極と負極とで劣化の速さが異なるということは、移行点より前と後とで可逆容量の低下の傾向も異なるということを意味する。従って、従来の近似法（即ち、ＢＯＬからの全ての測定値に基づいて、近似する線形的な関数を導出する手法）に基づいて求められたリチウムイオン二次電池の劣化の傾向は、実際の劣化の傾向からは逸脱したものとなり、リチウムイオン二次電池の寿命を正確に予測することができない欠点がある。 More specifically, although it depends on the composition of each material of the positive electrode and the negative electrode of the lithium ion secondary battery, in general, when the lithium ion secondary battery is started to be used, the irreversible capacity of the positive electrode is larger than the irreversible capacity of the negative electrode. many. Further, the speed of deterioration of the negative electrode (increase in irreversible capacity) is faster than the speed of deterioration of the positive electrode (increase in irreversible capacity). Therefore, in the early or middle of the life of the lithium ion secondary battery, the irreversible capacity of the positive electrode is larger than the irreversible capacity of the negative electrode, but after a certain point (hereinafter referred to as the transition point), the irreversible capacity of the negative electrode is the positive electrode. More than irreversible capacity. That is, the decrease in the reversible capacity of the lithium ion secondary battery is mainly related to the irreversible capacity of the positive electrode in the early to middle of the life, but is mainly related to the irreversible capacity of the negative electrode after the transition point. Further, the fact that the rate of deterioration differs between the positive electrode and the negative electrode means that the tendency of the reversible capacity to decrease differs between before and after the transition point. Therefore, the tendency of deterioration of the lithium ion secondary battery obtained based on the conventional approximation method (that is, a method of deriving an approximate linear function based on all the measured values from the BOL) is actual. There is a drawback that the life of the lithium-ion secondary battery cannot be accurately predicted because it deviates from the tendency of deterioration.

また、特許文献１および非特許文献１に記載されているような従来技術では、リチウムイオン二次電池の可逆容量の減少の主な原因となる極が一方の極から他方の極へ移行した時点、即ち、初期には高かった一方の極の劣化の度合（不可逆容量）よりも、初期には低かった他方の極の劣化の度合（不可逆容量）のほうが高くなった時点（移行点）を正確かつ容易に判別できない欠点がある。 Further, in the prior art as described in Patent Document 1 and Non-Patent Document 1, when the pole that is the main cause of the decrease in the reversible capacity of the lithium ion secondary battery shifts from one pole to the other pole. That is, the point at which the degree of deterioration of the other pole (irreversible capacity), which was initially low, is higher than the degree of deterioration of one pole (irreversible capacity), which was initially high, is accurate. Moreover, there is a drawback that it cannot be easily identified.

なお、ここでは寿命の初期、中期、末期などの期間を表す用語を用いたが、これらの用語は、単に、相対的に期間を表すために用いており、期間の長さ、開始時点、終了時点などを厳密に特定するものではない。 In addition, although terms for the period such as the early, middle, and end of life are used here, these terms are used only for expressing the relative period, and the length, start point, and end of the period are used. It does not strictly specify the time point.

また、特許文献２に記載されているような従来技術における正極および負極の劣化状態を示す尺度を求める構成では、正極および負極の劣化状態（電位）を、参照極を使用して測定するか、または充放電時の電池の電圧から推定するが、参照極を使用する場合には装置の構成が複雑になる欠点があり、また充放電時の電池の電圧から推定する場合には正確な値が得られない欠点がある。 Further, in the configuration for obtaining a scale indicating the deterioration state of the positive electrode and the negative electrode in the prior art as described in Patent Document 2, the deterioration state (potential) of the positive electrode and the negative electrode is measured by using a reference electrode or. Alternatively, it is estimated from the voltage of the battery at the time of charging / discharging, but there is a drawback that the configuration of the device becomes complicated when the reference electrode is used, and when estimating from the voltage of the battery at the time of charging / discharging, the accurate value is obtained. There is a drawback that cannot be obtained.

即ち、従来技術では、リチウムイオン二次電池の使用中における可逆容量の減少の傾向の移行点を正確かつ容易に判別することができない欠点がある。即ち、従来技術では、正極と負極との何れの可逆容量が多いかを判別できない欠点、従って、リチウムイオン二次電池の容量支配極が正極であるか負極であるかを判別できない欠点がある。 That is, the conventional technique has a drawback that the transition point of the tendency of the decrease in the reversible capacity during use of the lithium ion secondary battery cannot be accurately and easily determined. That is, in the prior art, there is a drawback that it is not possible to determine which of the positive electrode and the negative electrode has the larger reversible capacity, and therefore, it is not possible to determine whether the capacity controlling electrode of the lithium ion secondary battery is the positive electrode or the negative electrode.

なお、ここでは、容量支配極とは、正極と負極とのうちの、リチウムイオン二次電池の可逆容量を決定するほうの極、即ち、正極と負極とのうちの可逆容量の小さいほうの電極であると定義する。 Here, the capacity-dominant electrode is the electrode of the positive electrode and the negative electrode that determines the reversible capacity of the lithium ion secondary battery, that is, the electrode of the positive electrode and the negative electrode having the smaller reversible capacity. Is defined as.

更には、例えば、可逆容量の減少の主因が負極の可逆容量である期間と正極の可逆容量である期間とを区別して各期間に応じた種々の制御を行う、といった構成も実現できない欠点がある。 Further, for example, there is a drawback that it is not possible to realize a configuration in which the period in which the reversible capacity of the negative electrode is the main cause of the decrease in the reversible capacity is distinguished from the period in which the reversible capacity of the positive electrode is used, and various controls are performed according to each period. ..

そこで、本発明では、リチウムイオン二次電池の可逆容量の減少の主な原因となる極が一方の極から他方の極へ移行した時点、即ち、初期には低かった一方の極の劣化の度合（不可逆容量）が他方の極の劣化の度合（不可逆容量）より高くなった時点（移行点）、即ち、初期には多かった一方の極の可逆容量が他方の極の可逆容量より少なくなった時点を、リチウムイオン二次電池の充放電サイクルの放電期間後の充放電休止期間の開回路電圧(ＯＣＶ)の特性に基づいて求める。 Therefore, in the present invention, when the pole that is the main cause of the decrease in the reversible capacity of the lithium ion secondary battery shifts from one pole to the other pole, that is, the degree of deterioration of one pole, which was initially low, is low. When (irreversible capacity) becomes higher than the degree of deterioration of the other pole (irreversible capacity) (transition point), that is, the reversible capacity of one pole, which was initially large, became less than the reversible capacity of the other pole. The time point is determined based on the characteristics of the open circuit voltage (OCV) of the charge / discharge suspension period after the discharge period of the charge / discharge cycle of the lithium ion secondary battery.

更に、本発明では、移行点を求めた後、その移行点後のリチウムイオン二次電池の挙動に基づいて寿命の予測を行う。更に、本発明では、移行点後のリチウムイオン二次電池の性能を最大限に引き出すために、リチウムイオン二次電池の充放電と関連するシステムの制御を変更する。 Further, in the present invention, after the transition point is obtained, the life is predicted based on the behavior of the lithium ion secondary battery after the transition point. Further, in the present invention, in order to maximize the performance of the lithium ion secondary battery after the transition point, the control of the system related to the charging / discharging of the lithium ion secondary battery is changed.

本発明の第１の態様は、正極と負極を有する二次電池の可逆容量を決定する容量支配極を検出する二次電池の診断装置において、前記二次電池の診断装置は、正極の可逆容量と負極の可逆容量のいずれが大きいか判定することにより二次電池の可逆容量を決定する容量支配極を検出する検出手段を有する、二次電池の診断装置、ないし、正極と負極を有する二次電池の可逆容量を決定する容量支配極を検出する二次電池の診断方法において、前記二次電池の診断方法は、正極の可逆容量と負極の可逆容量のいずれが大きいか判定することにより二次電池の可逆容量を決定する容量支配極を検出する検出ステップを有する、二次電池の診断方法である。 A first aspect of the present invention is a secondary battery diagnostic device that detects a capacity-dominant electrode that determines the reversible capacity of a secondary battery having a positive electrode and a negative electrode. A secondary battery diagnostic device having a detection means for detecting a capacity controlling pole that determines the reversible capacity of the secondary battery by determining which of the reversible capacity of the negative and the negative is larger, or a secondary having a positive and a negative. In the method for diagnosing a secondary battery that detects the capacity-dominant electrode that determines the reversible capacity of the battery, the method for diagnosing the secondary battery is secondary by determining which of the reversible capacity of the positive electrode and the reversible capacity of the negative electrode is larger. A method for diagnosing a secondary battery, which comprises a detection step of detecting a capacity controlling pole that determines the reversible capacity of the battery.

本発明の第２の態様は、第１の態様の二次電池の診断装置において、前記検出手段は、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性に基づいて、正極の可逆容量と負極の可逆容量のいずれが大きいか判定する、二次電池の診断装置、ないし、第１の態様の二次電池の診断方法において、前記検出ステップは、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性に基づいて、正極の可逆容量と負極の可逆容量のいずれが大きいか判定する、二次電池の診断方法である。 A second aspect of the present invention is the secondary battery diagnostic device of the first aspect, wherein the detection means is a secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period. A secondary battery diagnostic device that determines whether the reversible capacity of the positive electrode or the reversible capacity of the negative electrode is larger based on the voltage characteristic of the open circuit voltage (OCV) of the above, or the diagnosis of the secondary battery of the first aspect. In the method, the detection step is based on the voltage characteristic of the open circuit voltage (OCV) of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period. This is a method for diagnosing a secondary battery to determine which of the reversible capacities of the negative electrode is larger.

本発明の第３の態様は、第２の態様の二次電池の診断装置において、前記検出手段は、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性として、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)を測定する測定部と、正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)の値として予め設定されている電圧値と、前記測定部において測定された、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)を比較する比較部とを含む、二次電池の診断装置、ないし、第２の態様の二次電池の診断方法において、前記検出ステップは、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性は、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ) を測定する測定ステップと、正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)の値として予め設定されている電圧値と、前記測定ステップにおいて測定された、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)を比較する比較ステップとを含む、二次電池の診断方法である。 A third aspect of the present invention is the secondary battery diagnostic device of the second aspect, wherein the detection means is a secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period. As the voltage characteristics of the open circuit voltage (OCV) of the above, the measuring unit for measuring the open circuit voltage (OCV) after a predetermined period of time has elapsed after the discharge of the charge / discharge cycle of the secondary battery is stopped, and the reversible capacity of the positive electrode and the negative electrode. The voltage value preset as the value of the open circuit voltage (OCV) after a predetermined period has elapsed after the discharge of the charge / discharge cycle of the secondary battery when the reversible capacities match, and the voltage value measured by the measuring unit. A secondary battery diagnostic device, or a secondary of a second embodiment, comprising a comparison unit for comparing the open circuit voltage (OCV) after a predetermined period of time has elapsed since the discharge of the charge / discharge cycle of the secondary battery was stopped. In the battery diagnostic method, the detection step is after the discharge stop of the charge / discharge cycle of the secondary battery, and the voltage characteristic of the open circuit voltage (OCV) of the secondary battery during the charge / discharge stop period is the voltage characteristic of the secondary battery. The charge / discharge cycle of the secondary battery when the measurement step for measuring the open circuit voltage (OCV) after the elapse of a predetermined period after the discharge stop of the charge / discharge cycle and the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match. A preset voltage value as an open circuit voltage (OCV) value after a predetermined period has elapsed after the discharge has stopped, and a predetermined period after the discharge stop of the charge / discharge cycle of the secondary battery measured in the measurement step. A method of diagnosing a secondary battery, comprising a comparison step of comparing the open circuit voltage (OCV) after lapse.

本発明の第４の態様は、第２の態様の二次電池の診断装置において、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性は、前記二次電池の充放電サイクルの放電停止後の所定期間内の開回路電圧(ＯＣＶ)の回復の速さであり、前記検出手段は、前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値を求める手段と、前記二次電池が劣化する過程で、正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値として予め設定されている速さの値と、求められた前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値とを比較する手段とを含む、二次電池の診断装置、ないし、第２の態様の二次電池の診断方法において、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性は、前記二次電池の充放電サイクルの放電停止後の所定期間内の開回路電圧(ＯＣＶ)の回復の速さであり、前記検出ステップは、前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値を求めるステップと、前記二次電池が劣化する過程で、正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値として予め設定されている速さの値と、求められた前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値とを比較するステップとを含む、二次電池の診断方法である。 A fourth aspect of the present invention is the open circuit voltage of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period in the secondary battery diagnostic device of the second aspect. The voltage characteristic of OCV) is the speed of recovery of the open circuit voltage (OCV) within a predetermined period after the discharge of the charge / discharge cycle of the secondary battery is stopped, and the detection means is the charge / discharge of the secondary battery. The means for obtaining the value of the recovery speed of the open circuit voltage (OCV) within a predetermined period after the cycle discharge is stopped and the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match in the process of deterioration of the secondary battery. The value of the speed set in advance as the value of the recovery speed of the open circuit voltage (OCV) within a predetermined period after the discharge of the charge / discharge cycle of the secondary battery is stopped, and the obtained value of the speed. A secondary battery diagnostic device, or second In the method for diagnosing a secondary battery according to the above embodiment, the voltage characteristic of the open circuit voltage (OCV) of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period is the secondary battery. The speed of recovery of the open circuit voltage (OCV) within a predetermined period after the charge / discharge cycle of the charge / discharge cycle is stopped, and the detection step is the said step within the predetermined period after the charge / discharge cycle of the secondary battery is stopped. The charge / discharge cycle of the secondary battery when the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match in the step of obtaining the value of the recovery speed of the open circuit voltage (OCV) and the process of deterioration of the secondary battery. After the discharge stop of the charge / discharge cycle of the secondary battery, the value of the preset speed as the value of the recovery speed of the open circuit voltage (OCV) within the predetermined period after the discharge stop of the secondary battery is stopped. It is a method of diagnosing a secondary battery including a step of comparing the value of the recovery speed of the open circuit voltage (OCV) within a predetermined period of time.

本発明の第５の態様は、第１～４の態様のいずれかの二次電池の診断装置において、更に、
前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を判定する判定手段を有する、二次電池の診断装置。ないし、第１～４の態様のいずれかの二次電池の診断方法において、更に、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を判定する判定ステップを有する、二次電池の診断方法である。 A fifth aspect of the present invention is further in the secondary battery diagnostic device according to any one of the first to fourth aspects.
A secondary battery having a determination means for determining a transition point where the capacity controlling electrode that determines the reversible capacity of the secondary battery has shifted from one of the positive electrode and the negative electrode to the other in the process of deterioration of the secondary battery. Diagnostic device. Alternatively, in the method for diagnosing a secondary battery according to any one of the first to fourth aspects, the positive electrode and the negative electrode are the capacity controlling electrodes that determine the reversible capacity of the secondary battery in the process of deterioration of the secondary battery. This is a method for diagnosing a secondary battery, which comprises a determination step for determining a transition point from any one of the above to the other.

本発明の第６の態様は、第５の態様の二次電池の診断装置において、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を、累積充放電サイクル回数により示す、二次電池の診断装置、ないし、第５の態様の二次電池の診断方法において、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を、累積充放電サイクル回数により示す、二次電池の診断方法である。 In the sixth aspect of the present invention, in the secondary battery diagnostic device of the fifth aspect, the capacity controlling poles that determine the reversible capacity of the secondary battery are positive and negative in the process of deterioration of the secondary battery. The secondary battery deteriorates in the secondary battery diagnostic device or the method for diagnosing the secondary battery according to the fifth aspect, which indicates the transition point from one of the above to the other by the cumulative charge / discharge cycle count. This is a method for diagnosing a secondary battery, in which the transition point at which the capacity controlling electrode that determines the reversible capacity of the secondary battery shifts from one of the positive electrode and the negative electrode to the other is indicated by the number of cumulative charge / discharge cycles. ..

本発明の第７の態様は、第５又は６の二次電池の診断装置において、更に、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点以降の、前記二次電池の劣化状態の計時変化を検出して、前記二次電池の寿命性能を予測する寿命予測手段を有する、二次電池の診断装置、ないし、第５又は６の二次電池の診断方法において、更に、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点以降の、前記二次電池の劣化状態の計時変化を検出して、前記二次電池の寿命性能を予測する寿命予測ステップを有する、二次電池の診断方法である。 A seventh aspect of the present invention is that in the diagnostic device of the fifth or sixth secondary battery, the capacity controlling electrode that determines the reversible capacity of the secondary battery is a positive electrode in the process of deterioration of the secondary battery. A secondary battery having a life prediction means for predicting the life performance of the secondary battery by detecting a timed change in the deterioration state of the secondary battery after the transition point from one of the two to the negative. In the diagnostic device of the above, or the method of diagnosing the fifth or sixth secondary battery, the capacity controlling poles that determine the reversible capacity of the secondary battery in the process of deterioration of the secondary battery are the positive and negative electrodes. A method for diagnosing a secondary battery, which comprises a life prediction step for predicting the life performance of the secondary battery by detecting a timed change in the deterioration state of the secondary battery after the transition point from one of them to the other. Is.

本発明の第８の態様は、第５～７の態様の二次電池の診断装置を含む二次電池制御システムにおいて、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点に、前記二次電池に対する制御を変更する制御手段を有する、二次電池制御システム、ないし、第５～７の態様の二次電池の診断方法を含む二次電池制御方法において、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点に、前記二次電池に対する制御を変更する制御ステップを有する、二次電池制御方法である。 An eighth aspect of the present invention is a secondary battery control system including the secondary battery diagnostic device of the fifth to seventh aspects, in which the reversible capacity of the secondary battery is determined in the process of deterioration of the secondary battery. A secondary battery control system, or a fifth to seventh aspect, comprising a control means for changing the control of the secondary battery at a transition point where the capacity controlling electrode to be used shifts from one of the positive electrode and the negative electrode to the other. In the secondary battery control method including the method for diagnosing the secondary battery, the capacity controlling electrode that determines the reversible capacity of the secondary battery is determined from one of the positive electrode and the negative electrode in the process of deterioration of the secondary battery. It is a secondary battery control method having a control step for changing the control for the secondary battery at the transition point shifted to.

本発明の第９の態様は、第１～７の態様の二次電池の診断装置を含む二次電池の充電装置、ないし、第１～７の態様の二次電池の診断方法を含む二次電池の充電方法である。 A ninth aspect of the present invention is a secondary battery charging device including the secondary battery diagnostic device of the first to seventh aspects, or a secondary battery including the secondary battery diagnostic method of the first to seventh aspects. How to charge the battery.

本発明の第１０の態様は、第１～７の態様の二次電池の診断方法を実行するためのプログラムであり、本発明の第１１の態様は、第１～７の態様の二次電池の診断方法を実行するためのプログラムを記録した記録媒体である。 The tenth aspect of the present invention is a program for executing the diagnostic method of the secondary battery of the first to seventh aspects, and the eleventh aspect of the present invention is the secondary battery of the first to seventh aspects. It is a recording medium on which a program for executing the diagnostic method of is recorded.

本発明を用いると、リチウムイオン二次電池の可逆容量の減少の主な原因となる極が一方の極から他方の極へ移行した時点（移行点）を正確かつ容易に判別できる効果がある。即ち、本発明では、正極と負極との何れの可逆容量が多いかを判別できる効果、従って、リチウムイオン二次電池の容量支配極が正極であるか負極であるかを判別できる効果がある。また、本発明を用いることにより、診断装置の構成を簡素化できる効果がある。また、本発明では、移行点以降の二次電池の可逆容量の減少に基づいて、リチウムイオン二次電池の寿命を正確に予測することができる効果がある。更には、本発明では、二次電池の可逆容量の減少の主因が負極である期間と正極である期間とを区別できるので、例えば、各期間に応じた種々の制御を行う構成を実現できる効果がある。 When the present invention is used, there is an effect that the time point (transition point) at which the pole, which is the main cause of the decrease in the reversible capacity of the lithium ion secondary battery, shifts from one pole to the other pole can be accurately and easily determined. That is, in the present invention, there is an effect that it is possible to determine which of the positive electrode and the negative electrode has the larger reversible capacity, and therefore, there is an effect that it is possible to determine whether the capacity controlling electrode of the lithium ion secondary battery is the positive electrode or the negative electrode. Further, by using the present invention, there is an effect that the configuration of the diagnostic apparatus can be simplified. Further, the present invention has an effect that the life of the lithium ion secondary battery can be accurately predicted based on the decrease in the reversible capacity of the secondary battery after the transition point. Further, in the present invention, since the period in which the negative electrode is the main cause and the period in which the positive electrode is the main cause of the decrease in the reversible capacity of the secondary battery can be distinguished, for example, it is possible to realize a configuration in which various controls are performed according to each period. There is.

図１は、リチウムイオン二次電池に対して２５℃で１Ｃでの充放電サイクルを行った際の、リチウムイオン二次電池の可逆容量と充放電サイクル回数との関係を示すグラフである。FIG. 1 is a graph showing the relationship between the reversible capacity of a lithium ion secondary battery and the number of charge / discharge cycles when the lithium ion secondary battery is charged / discharged at 1 C at 25 ° C. 図２は、充放電サイクルにおける放電期間後の１０分の充放電休止期間の直後のリチウムイオン二次電池のＯＣＶと、充放電サイクル回数との関係を示すグラフである。FIG. 2 is a graph showing the relationship between the OCV of the lithium ion secondary battery immediately after the 10-minute charge / discharge suspension period after the discharge period in the charge / discharge cycle and the number of charge / discharge cycles. 図３は、第２回目、第２００回目、第４００回目、および第６００回目の充放電サイクルのときの、放電期間後の１０分の充放電休止期間の間のリチウムイオン二次電池のＯＣＶと、時間との関係を示すグラフである。FIG. 3 shows the OCV of the lithium ion secondary battery during the 10-minute charge / discharge pause period after the discharge period during the second, 200th, 400th, and 600th charge / discharge cycles. , Is a graph showing the relationship with time. 図４は、本発明の実施形態の診断装置の構成を概略的に示す。FIG. 4 schematically shows the configuration of the diagnostic device according to the embodiment of the present invention. 図５は、第１実施形態における診断装置の動作を示すフローチャートである。FIG. 5 is a flowchart showing the operation of the diagnostic device according to the first embodiment. 図６は、第２実施形態における診断装置の動作を示すフローチャートである。FIG. 6 is a flowchart showing the operation of the diagnostic device according to the second embodiment. 図７は、第３実施形態における診断装置の動作を示すフローチャートである。FIG. 7 is a flowchart showing the operation of the diagnostic device according to the third embodiment. 図８は、リチウムイオン二次電池の充電を２５℃で１Ｃで行った後、０．２Ｃで放電した際の容量維持率と、充放電サイクル回数との関係を示すグラフである。FIG. 8 is a graph showing the relationship between the capacity retention rate and the number of charge / discharge cycles when the lithium ion secondary battery is charged at 25 ° C. at 1 C and then discharged at 0.2 C. 図９は、リチウムイオン二次電池の充電を２５℃で１Ｃで行った後、０．２Ｃで放電した際の容量維持率と、充放電サイクル回数との関係を示すグラフである。FIG. 9 is a graph showing the relationship between the capacity retention rate and the number of charge / discharge cycles when the lithium ion secondary battery is charged at 25 ° C. at 1 C and then discharged at 0.2 C.

本発明に到る過程では、下記の条件で実験を行った。 In the process leading to the present invention, experiments were conducted under the following conditions.

（１）使用するリチウムイオン二次電池：６００ｍＡｈ級
・正極
両面塗工正極：９２ｍｍ×９２ｍｍ×２枚
LiNi1/3Co1/3Mn1/3O2(92wt%)、カーボンブラック(4wt%)、PVdF(4wt%)
片面塗工量１４ｍｇ/ｃｍ２を２４μｍのＡｌ箔に塗工後、プレスして真空乾燥
・負極
両面黒鉛負極：９４ｍｍ×９４ｍｍ×３枚
黒鉛(95wt%)、SBR(2.5wt%)、CMC(2.5wt%)
片面塗工量８．５ｍｇ/ｃｍ２を１２μｍのＣｕ箔に塗工後、プレスして真空乾燥。
・セパレータ
３ＤＯＭ社ＰＩ（ポリイミド）セパレータ：９６ｍｍ×９６ｍｍ×４枚
・電解液
上記のものを積層した発電素子をアルミラミネート外装体に挿入し、1M LiPF6/EC+DEC(3:7)を６ｍｌ注液して封止。 (1) Lithium-ion secondary battery to be used: 600mAh class ・ Positive electrode Double-sided coating Positive electrode: 92mm x 92mm x 2 sheets
LiNi1 / 3Co1 / 3Mn1 / 3O2 (92wt%), carbon black (4wt%), PVdF (4wt%)
Single-sided coating amount of 14 mg / cm 2 is applied to 24 μm Al foil, then pressed and vacuum dried. ・ Negative electrode Double-sided graphite Negative electrode: 94 mm x 94 mm x 3 sheets Graphite (95 wt%), SBR (2.5 wt%), CMC ( 2.5wt%)
One-sided coating amount of 8.5 mg / cm 2 is applied to 12 μm Cu foil, then pressed and vacuum dried.
・ Separator 3DOM PI (polyimide) separator: 96 mm × 96 mm × 4 sheets ・ Electrolyte solution Insert the power generation element laminated with the above into the aluminum laminated exterior body, and inject 6 ml of 1M LiPF6 / EC + DEC (3: 7). Liquid and seal.

（２）２５℃、６００ｍＡでの充放電サイクル試験の条件
充電：６００ｍＡ－４．２Ｖ、ＣＣＣＶ（３０ｍＡ）
充電休止：１０分
放電：６００ｍＡ－２．８Ｖ、（ＣＣ）
放電休止：１０分。 (2) Conditions for charge / discharge cycle test at 25 ° C and 600mA Charging: 600mA-4.2V, CCCV (30mA)
Charging pause: 10 minutes Discharge: 600mA-2.8V, (CC)
Discharge pause: 10 minutes.

（３）２５℃、１２０ｍＡでの容量確認試験の条件
充電：１２０ｍＡ－４．２Ｖ、ＣＣＣＶ（６．５ｈ）
充電休止：１０分
放電：１２０ｍＡ－２．８Ｖ、ＣＣ
放電休止：１０分
６００ｍＡ充放電サイクル時の２５０サイクル毎に実施。 (3) Conditions for capacity confirmation test at 25 ° C and 120 mA Charging: 120 mA-4.2 V, CCCV (6.5 h)
Charging pause: 10 minutes Discharge: 120mA-2.8V, CC
Discharge pause: Performed every 250 cycles during a 600mA charge / discharge cycle for 10 minutes.

ＢＯＬは、リチウムイオン二次電池を使用開始する前の時点とし、ＥＯＬは、容量維持率８０％を維持できなくなった時点とする。また、ＢＯＬ時の容量支配極を正極とする。放電終止電圧（最小の開回路電圧）を２．８Ｖとする。放電開始時の電圧（最大の開回路電圧）は４．２Ｖとする。以下では、開回路電圧をＯＣＶと記載する。 BOL is a time point before the start of use of the lithium ion secondary battery, and EOL is a time point when the capacity retention rate of 80% cannot be maintained. Further, the capacitance controlling electrode at the time of BOL is used as the positive electrode. The discharge cutoff voltage (minimum open circuit voltage) is 2.8V. The voltage at the start of discharge (maximum open circuit voltage) is 4.2V. Hereinafter, the open circuit voltage is referred to as OCV.

図１は、リチウムイオン二次電池に対して２５℃で１Ｃでの充放電サイクルを行った際の、リチウムイオン二次電池の可逆容量と充放電サイクル回数との関係を示すグラフである。縦軸は、リチウムイオン二次電池の可逆容量（ｍＡｈ）を示し、横軸は、充放電サイクル回数をその平方根として示す。図１のグラフの実線は、測定値に基づいて描かれたものであり、点線は、それらの測定値の関係性に最も近似する関数を示すものである。この関数は、ｙ＝－１．８８９８ｘ＋６５３．２１であり、この関数と測定値との間での決定係数（Ｒ２）は０．９７５８であった。 FIG. 1 is a graph showing the relationship between the reversible capacity of a lithium ion secondary battery and the number of charge / discharge cycles when the lithium ion secondary battery is charged / discharged at 1 C at 25 ° C. The vertical axis shows the reversible capacity (mAh) of the lithium ion secondary battery, and the horizontal axis shows the number of charge / discharge cycles as the square root thereof. The solid line in the graph of FIG. 1 is drawn based on the measured values, and the dotted line shows the function that most closely matches the relationship between the measured values. This function had y = -1.88898x + 653.21 and the coefficient of determination (R 2 ) between this function and the measured value was 0.9758.

図１のグラフの実線の部分では、充放電サイクル回数が約４００回（横軸の２０）の位置に変曲点（上記の移行点に対応）があった。即ち、リチウムイオン二次電池の可逆容量に影響を及ぼす極、即ち、容量支配極が一方の極（正極）から他方の極（負極）へ移行した時点は、充放電サイクル回数が約４００回の時点であることが分かった。 In the solid line portion of the graph of FIG. 1, there was an inflection point (corresponding to the above transition point) at a position where the number of charge / discharge cycles was about 400 times (20 on the horizontal axis). That is, at the time when the electrode that affects the reversible capacity of the lithium ion secondary battery, that is, the capacity controlling electrode shifts from one electrode (positive electrode) to the other electrode (negative electrode), the number of charge / discharge cycles is about 400. It turned out to be a point in time.

また、実験では、充放電サイクルにおける放電期間後の１０分の充放電休止期間の直後のリチウムイオン二次電池のＯＣＶを、所定の充放電サイクル回数毎に測定し、且つ１０分の休止の間のリチウムイオン二次電池のＯＣＶを、時間と対応させて測定した。 In the experiment, the OCV of the lithium ion secondary battery immediately after the 10-minute charge / discharge suspension period after the discharge period in the charge / discharge cycle was measured at each predetermined charge / discharge cycle count, and during the 10-minute pause. The OCV of the lithium ion secondary battery was measured in correspondence with time.

図２は、充放電サイクルにおける放電期間後の１０分の充放電休止期間の直後のリチウムイオン二次電池のＯＣＶと、充放電サイクル回数との関係を示すグラフである。図３は、第２回目、第２００回目、第４００回目、および第６００回目の充放電サイクルのときの、放電期間後の１０分の充放電休止期間の間のリチウムイオン二次電池のＯＣＶと、時間との関係を示すグラフである。 FIG. 2 is a graph showing the relationship between the OCV of the lithium ion secondary battery immediately after the 10-minute charge / discharge suspension period after the discharge period in the charge / discharge cycle and the number of charge / discharge cycles. FIG. 3 shows the OCV of the lithium ion secondary battery during the 10-minute charge / discharge pause period after the discharge period during the second, 200th, 400th, and 600th charge / discharge cycles. , Is a graph showing the relationship with time.

図２のグラフの縦軸は、放電期間後の１０分の充放電休止期間の直後のＯＣＶ（Ｖ）を示し、横軸は、充放電サイクル回数をその平方根として示す。図２のグラフに示されているように、ＯＣＶは、４００回目の充放電サイクル（グラフ横軸の２０）あたりまでは比例的に減少しているが、４００回目の充放電サイクルあたりからは一定値に近い値となっている。即ち、このグラフから、４００回目の充放電サイクルあたりでリチウムイオン二次電池の充放電の特性が変化したこと理解できる。 The vertical axis of the graph of FIG. 2 shows the OCV (V) immediately after the 10-minute charge / discharge suspension period after the discharge period, and the horizontal axis shows the number of charge / discharge cycles as its square root. As shown in the graph of FIG. 2, the OCV decreases proportionally up to the 400th charge / discharge cycle (20 on the horizontal axis of the graph), but is constant from the 400th charge / discharge cycle. The value is close to the value. That is, from this graph, it can be understood that the charge / discharge characteristics of the lithium ion secondary battery changed around the 400th charge / discharge cycle.

図３のグラフの縦軸は、リチウムイオン二次電池のＯＣＶ（Ｖ）を示し、横軸は、時間（秒）を示す。時間が０のとき、即ち、放電期間の終了直後は、規定された最小のＯＣＶ（２．８Ｖ）となっている。その後、充電期間が開始するまでの１０分の間に、リチウムイオン二次電池のＯＣＶは自然に少し回復する。このグラフは、その電圧の回復の特性を示すものである。また、このグラフでは、第４００回目の充放電サイクルに関する曲線と第６００回目の充放電サイクルに関する曲線とが実質的に重なっているので、１本の曲線のように表されている。 The vertical axis of the graph of FIG. 3 shows the OCV (V) of the lithium ion secondary battery, and the horizontal axis shows the time (seconds). When the time is 0, that is, immediately after the end of the discharge period, the specified minimum OCV (2.8V) is obtained. Then, during the 10 minutes until the charging period starts, the OCV of the lithium ion secondary battery naturally recovers a little. This graph shows the characteristics of the voltage recovery. Further, in this graph, since the curve relating to the 400th charge / discharge cycle and the curve relating to the 600th charge / discharge cycle substantially overlap, they are represented as one curve.

図３のグラフからは、６００秒（１０分）の時点でのＯＣＶに関しては、第２回目の充放電サイクルと関連するものが最大であり、第４００回目の充放電サイクルまでに漸次的に下がり、第４００回目の充放電サイクル以降はほぼ一定になることが、理解できる。即ち、このグラフからも、図２のグラフと同様に、４００回目の充放電サイクルあたりでリチウムイオン二次電池の充放電の特性が変化したことが理解できる。 From the graph of FIG. 3, regarding OCV at 600 seconds (10 minutes), the one related to the second charge / discharge cycle is the largest, and it gradually decreases by the 400th charge / discharge cycle. It can be understood that it becomes almost constant after the 400th charge / discharge cycle. That is, from this graph as well, it can be understood that the charge / discharge characteristics of the lithium ion secondary battery changed around the 400th charge / discharge cycle, as in the graph of FIG.

図１のグラフと、図２および図３のそれぞれのグラフからは、同じ結果、即ち、グラフの変化する点が４００回目の充放電サイクルあたりであることが、導き出された。この結果から、図２および図３のグラフに示されているリチウムイオン二次電池の充放電の特性の変化が、容量支配極が一方の極（正極）から他方の極（負極）へ移行したことを示すことが理解できる。 From the graph of FIG. 1 and the graphs of FIGS. 2 and 3, it was derived that the same result, that is, the point where the graph changes is around the 400th charge / discharge cycle. From this result, the change in the charge / discharge characteristics of the lithium ion secondary battery shown in the graphs of FIGS. 2 and 3 caused the capacity-dominant electrode to shift from one electrode (positive electrode) to the other electrode (negative electrode). It can be understood to show that.

次に、リチウムイオン二次電池の容量支配極が一方の極から他方の極へ移行した時点（移行点）を決定するための１つの実施形態（第１実施形態）について説明する。第１実施形態では、二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧の電圧特性として、二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧（ＯＣＶ）を測定することにより、容量支配極が正極から負極へ移行した時点（累積充放電サイクル回数）、即ち、上記の移行点を決定する。この実施形態では、所定の充放電休止期間を１０分とし、所定の充放電休止期間中の所定の時点を１０分の時点とする。 Next, one embodiment (first embodiment) for determining the time point (transition point) at which the capacity-dominant pole of the lithium ion secondary battery shifts from one pole to the other pole will be described. In the first embodiment, the voltage characteristic of the open circuit voltage of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period is a predetermined value after the discharge stop of the charge / discharge cycle of the secondary battery. By measuring the open circuit voltage (OCV) after the lapse of the period, the time point at which the capacitance controlling electrode shifts from the positive electrode to the negative voltage (cumulative charge / discharge cycle count), that is, the above transition point is determined. In this embodiment, the predetermined charge / discharge suspension period is 10 minutes, and the predetermined time during the predetermined charge / discharge suspension period is 10 minutes.

図４は、移行点を決定する診断装置の構成を概略的に示す。移行点を決定する診断装置１は、データの入出力を行う入出力部２と、移行点に対応する所定電圧（実験等により決定された参照ＯＣＶ）、行われた充放電サイクル回数（累積充放電サイクル回数）、および測定を行う所定の充放電サイクルの回を記憶する記憶部３と、所定の充放電サイクルの回の時の放電期間後の１０分の充放電休止期間の直後のＯＣＶ（測定ＯＣＶ）を測定する測定部４と、参照ＯＣＶと測定ＯＣＶとを比較する比較部５と、これら各部を制御する制御部６とを含む。この測定部４と比較部５を併せて検出手段と呼ぶ場合がある。図５は、第１実施形態における診断装置の動作を示すフローチャートである。この診断装置は、このフローチャートに基づくプログラムによって実現されてもよい。この診断装置の動作について、図５を参照して説明する。 FIG. 4 schematically shows the configuration of a diagnostic device that determines a transition point. The diagnostic device 1 that determines the transition point includes an input / output unit 2 that inputs / outputs data, a predetermined voltage corresponding to the transition point (reference OCV determined by an experiment or the like), and the number of charge / discharge cycles performed (cumulative charge). The storage unit 3 that stores the number of discharge cycles) and the predetermined charge / discharge cycle times to be measured, and the OCV immediately after the 10-minute charge / discharge pause period after the discharge period at the time of the predetermined charge / discharge cycle times. It includes a measurement unit 4 for measuring the measurement OCV), a comparison unit 5 for comparing the reference OCV and the measurement OCV, and a control unit 6 for controlling each of these units. The measuring unit 4 and the comparing unit 5 may be collectively referred to as a detecting means. FIG. 5 is a flowchart showing the operation of the diagnostic device according to the first embodiment. This diagnostic device may be realized by a program based on this flowchart. The operation of this diagnostic device will be described with reference to FIG.

記憶部に記憶される「行われた充放電サイクル回数（累積充放電サイクル回数）」は、充放電サイクルが行われる度に更新される構成とする。このような構成は周知であるので説明は省略する。 The "number of charge / discharge cycles performed (cumulative number of charge / discharge cycles)" stored in the storage unit is configured to be updated each time the charge / discharge cycle is performed. Since such a configuration is well known, the description thereof will be omitted.

ステップＳ１．１において、入力部１を介して、記憶部３に、実験等により決定された参照ＯＣＶと、測定を行う所定の充放電サイクルの回とを含む初期データを記憶する。この参照ＯＣＶは、二次電池が劣化する過程で、正極の可逆容量と負極の可逆容量が一致したときの二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)の値となる。測定を行う所定の充放電サイクルの回については、適宜に設定することが可能であり、例えば、測定を行う回の回数（例えば、第１０回目、第２０回目、・・・など）を示すデータを記憶する構成にすることも、測定を行う回の間隔（毎回、１００回毎など）を示すデータを記憶する構成にすることもできる。また、測定を毎回行う場合には、記憶部３に「測定を行う所定の充放電サイクルの回」を記憶する必要はない。 In step S1.1, initial data including a reference OCV determined by an experiment or the like and a predetermined charge / discharge cycle for measurement is stored in the storage unit 3 via the input unit 1. This reference OCV is the open circuit voltage (OCV) after a predetermined period of time has elapsed after the discharge of the charge / discharge cycle of the secondary battery is stopped when the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match in the process of deterioration of the secondary battery. ). The number of predetermined charge / discharge cycles for measurement can be appropriately set, and for example, data indicating the number of times for measurement (for example, the 10th time, the 20th time, ...). Can be configured to store data, or data indicating the interval between measurements (every time, every 100 times, etc.) can be stored. Further, when the measurement is performed every time, it is not necessary to store the "predetermined charge / discharge cycle times for measuring" in the storage unit 3.

ステップＳ１．２において、制御部６は、記憶部３に記憶されているデータに基づいて、現時点の充放電サイクルが、測定を行う所定の充放電サイクルの回であるか否かを判定する。所定の充放電サイクルの回ではないと判定された場合（図５のステップＳ１．２のＮｏ）、次の充放電サイクルが行われる時まで待機し、その時に、再度、その充放電サイクルが、測定を行う所定の充放電サイクルの回であるか否かを判定する。 In step S1.2, the control unit 6 determines whether or not the current charge / discharge cycle is a predetermined charge / discharge cycle for measurement based on the data stored in the storage unit 3. If it is determined that the charge / discharge cycle is not the predetermined number (No in step S1.2 in FIG. 5), the process waits until the next charge / discharge cycle is performed, and at that time, the charge / discharge cycle is again changed. It is determined whether or not the measurement is performed at a predetermined charge / discharge cycle.

ステップＳ１．２において、現時点の充放電サイクルが、測定を行う所定の充放電サイクルの回であると制御部６が判断した場合、処理はステップＳ１．３へ進む。 If the control unit 6 determines in step S1.2 that the current charge / discharge cycle is a predetermined charge / discharge cycle for measurement, the process proceeds to step S1.3.

ステップＳ１．３において、制御部６は、測定部５を用いて、その充放電サイクルの放電期間後の１０分の充放電休止期間における１０分の時点のＯＣＶ（測定ＯＣＶ）を測定する。 In step S1.3, the control unit 6 uses the measurement unit 5 to measure the OCV (measurement OCV) at 10 minutes in the charge / discharge pause period of 10 minutes after the discharge period of the charge / discharge cycle.

次に、ステップＳ１．４において、制御部６は、比較部５を用いて、記憶部６に記憶されている参照ＯＣＶと、測定部４により測定された測定ＯＣＶとを比較する。測定ＯＣＶが参照ＯＣＶ以下ではない場合、処理はステップＳ１．２へ戻る。測定ＯＣＶが参照ＯＣＶ以下である場合はステップＳ１．５へ進み、制御部６は、その充放電サイクルの回が、可逆容量の低下の傾向が変わる移行点であると判定する。即ち、制御部６は、その充放電サイクルの回の時点が、容量支配極が一方の極から他方の極へ移行した時点であると判定する。 Next, in step S1.4, the control unit 6 uses the comparison unit 5 to compare the reference OCV stored in the storage unit 6 with the measurement OCV measured by the measurement unit 4. If the measured OCV is not less than or equal to the reference OCV, the process returns to step S1.2. If the measured OCV is equal to or less than the reference OCV, the process proceeds to step S1.5, and the control unit 6 determines that the charge / discharge cycle is a transition point at which the tendency of the decrease in the reversible capacity changes. That is, the control unit 6 determines that the time point of the charge / discharge cycle is the time point when the capacitance controlling pole shifts from one pole to the other pole.

なお、第１実施形態では、ＯＣＶを測定する時点を放電期間の１０分後と設定したが、ＯＣＶを測定する時点は、これには限定されない。例えば、図３のグラフに基づくと、放電期間終了からある程度の時間が経過した後は、各回の充放電サイクル後のＯＣＶの差異が明確になる。従って、各回の充放電サイクル後のＯＣＶの差異が明確になる時点であれば、何れの時点のＯＣＶを用いてもよい。 In the first embodiment, the time point for measuring OCV is set to 10 minutes after the discharge period, but the time point for measuring OCV is not limited to this. For example, based on the graph of FIG. 3, after a certain amount of time has passed from the end of the discharge period, the difference in OCV after each charge / discharge cycle becomes clear. Therefore, any time point OCV may be used as long as the difference in OCV after each charge / discharge cycle becomes clear.

以上が、第１実施形態における移行点を決定する診断装置の動作である。記憶部は、診断装置に上記の動作を行わせるプログラムを記憶いしている。 The above is the operation of the diagnostic device that determines the transition point in the first embodiment. The storage unit stores a program that causes the diagnostic device to perform the above operation.

次に、リチウムイオン二次電池の容量支配極が一方の極から他方の極へ移行した時点（移行点）を決定するための別の実施形態（第２実施形態）について説明する。第２実施形態では、充放電サイクルの放電期間終了後の充放電休止期間中の所定期間におけるＯＣＶの上昇速度（ΔＯＣＶ）に基づいて移行点を決定する。 Next, another embodiment (second embodiment) for determining the time point (transition point) at which the capacity-dominant pole of the lithium ion secondary battery shifts from one pole to the other pole will be described. In the second embodiment, the transition point is determined based on the rate of increase of OCV (ΔOCV) in a predetermined period during the charge / discharge suspension period after the end of the discharge period of the charge / discharge cycle.

第２実施形態の診断装置は、ハードウェアの構成としては第１実施形態の診断装置と同様の構成を有するが、ＯＣＶの測定方法と、移行点を決定する際に用いる比較対象とが異なるので、診断装置の各部は、それらに対応した構成を備える。 The diagnostic device of the second embodiment has the same hardware configuration as the diagnostic device of the first embodiment, but the OCV measurement method and the comparison target used when determining the transition point are different. , Each part of the diagnostic apparatus has a configuration corresponding to them.

第２実施形態では、放電期間終了後の所定期間を、１０秒後の時点から４０秒後の時点までの３０秒間とし、その３０秒間における１秒あたりのＯＣＶの上昇速度を比較するものとする。従って、記憶部３には、実験等により決定されたＯＣＶの上昇速度（参照ΔＯＣＶ）が記憶される。この参照ΔＯＣＶは、二次電池が劣化する過程で、正極の可逆容量と負極の可逆容量が一致したときの二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値となる。測定部４は、放電期間終了後の１０秒後から４０秒後までの３０秒間のＯＣＶを測定する構成を備える。比較部５は更に、測定部４で測定された３０秒間のＯＣＶに基づいて、その３０秒間における１秒あたりのＯＣＶの上昇速度（測定ΔＯＣＶ）を計算する構成（計算手段）と、基準ΔＯＣＶと測定ΔＯＣＶとを比較する構成を備える。制御部６は、これら各部を制御する構成を備える。図６は、第２実施形態における診断装置の動作を示すフローチャートである。この診断装置の動作について、図６を参照して説明する。 In the second embodiment, the predetermined period after the end of the discharge period is 30 seconds from the time point after 10 seconds to the time point after 40 seconds, and the rate of increase in OCV per second in the 30 seconds is compared. .. Therefore, the storage unit 3 stores the rate of increase of OCV (reference ΔOCV) determined by an experiment or the like. This reference ΔOCV is the open circuit voltage (OCV) within a predetermined period after the discharge of the charge / discharge cycle of the secondary battery is stopped when the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match in the process of deterioration of the secondary battery. ) Is the value of the recovery speed. The measuring unit 4 has a configuration for measuring OCV for 30 seconds from 10 seconds to 40 seconds after the end of the discharge period. The comparison unit 5 further includes a configuration (calculation means) for calculating the rate of increase in OCV per second (measurement ΔOCV) in the 30 seconds based on the OCV for 30 seconds measured by the measurement unit 4, and a reference ΔOCV. It has a configuration for comparing with the measurement ΔOCV. The control unit 6 has a configuration for controlling each of these units. FIG. 6 is a flowchart showing the operation of the diagnostic device according to the second embodiment. The operation of this diagnostic device will be described with reference to FIG.

ステップＳ２．１において、入出力部２を介して、記憶部３に、実験等により決定された参照ΔＯＣＶと、測定を行う所定の充放電サイクルの回とを含む初期データを記憶する。測定を行う所定の充放電サイクルの回については、ステップＳ１．１と同様に、適宜に設定することが可能である。 In step S2.1, initial data including a reference ΔOCV determined by an experiment or the like and a predetermined charge / discharge cycle for measurement is stored in the storage unit 3 via the input / output unit 2. The number of predetermined charge / discharge cycles for measuring can be appropriately set in the same manner as in step S1.1.

ステップＳ２．２において、制御部６は、記憶部に記憶されているデータに基づいて、現時点の充放電サイクルが、測定を行う所定の充放電サイクルの回であるか否かを判定する。所定の充放電サイクルの回ではないと判定された場合（図６のステップＳ２．２のＮｏ）、次の充放電サイクルが行われる時まで待機し、その時に、再度、その充放電サイクルが、測定を行う所定の充放電サイクルの回であるか否かを判定する。 In step S2.2, the control unit 6 determines whether or not the current charge / discharge cycle is a predetermined charge / discharge cycle for measurement based on the data stored in the storage unit. If it is determined that the charge / discharge cycle is not the predetermined number (No in step S2.2 in FIG. 6), the process waits until the next charge / discharge cycle is performed, and at that time, the charge / discharge cycle is again performed. It is determined whether or not the measurement is performed at a predetermined charge / discharge cycle.

ステップＳ２．２において、現時点の充放電サイクルが、測定を行う所定の充放電サイクルの回であると制御部６が判断した場合、処理はステップＳ２．３へ進む。 If the control unit 6 determines in step S2.2 that the current charge / discharge cycle is a predetermined charge / discharge cycle for measurement, the process proceeds to step S2.3.

ステップＳ２．３において、制御部６は、測定部４を用いて、その充放電サイクルの放電期間後の充放電休止期間中の１０秒の時点から４０秒の時点までの３０秒間のＯＣＶを測定する。 In step S2.3, the control unit 6 measures the OCV for 30 seconds from the time point of 10 seconds to the time point of 40 seconds during the charge / discharge suspension period after the discharge period of the charge / discharge cycle using the measurement unit 4. do.

ステップＳ２．４において、制御部６は、比較部の計算手段を用いて、その３０秒間に測定されたＯＣＶから、その３０秒間における１秒あたりのＯＣＶの上昇速度（測定ΔＯＣＶ）を計算する。 In step S2.4, the control unit 6 calculates the rate of increase of OCV per second (measurement ΔOCV) per second in the 30 seconds from the OCV measured in the 30 seconds by using the calculation means of the comparison unit.

次に、ステップＳ２．５において、制御部６は、比較部５を用いて、記憶部３に記憶されている参照ΔＯＣＶと、比較部５の計算手段により計算された測定ΔＯＣＶとを比較する。測定ΔＯＣＶが参照ΔＯＣＶ以下ではない場合、処理はステップＳ２．２へ戻る。測定ΔＯＣＶが参照ΔＯＣＶ以下である場合はステップＳ２．６へ進み、制御部６は、その充放電サイクルの回が、可逆容量の低下の傾向が変わる移行点であると判定する。即ち、制御部６は、その充放電サイクルの回の時点が、容量支配極が一方の極から他方の極へ移行した時点であると判定する。 Next, in step S2.5, the control unit 6 uses the comparison unit 5 to compare the reference ΔOCV stored in the storage unit 3 with the measurement ΔOCV calculated by the calculation means of the comparison unit 5. If the measurement ΔOCV is not less than or equal to the reference ΔOCV, the process returns to step S2.2. If the measurement ΔOCV is equal to or less than the reference ΔOCV, the process proceeds to step S2.6, and the control unit 6 determines that the charge / discharge cycle is a transition point at which the tendency of the decrease in the reversible capacity changes. That is, the control unit 6 determines that the time point of the charge / discharge cycle is the time point when the capacitance controlling pole shifts from one pole to the other pole.

なお、第２実施形態では、ΔＯＣＶを求めるためのＯＣＶの測定期間を、放電期間終了後の充放電休止期間の１０秒の時点から４０秒の時点までの３０秒間としたが、ＯＣＶの測定期間はこれに限定されない。ΔＯＣＶを求めるためのＯＣＶの測定期間は、各回の充放電サイクル後の充放電休止期間中のΔＯＣＶの差異が明確になる期間であれば、何れの期間としてもよい。 In the second embodiment, the OCV measurement period for obtaining ΔOCV is 30 seconds from the time point of 10 seconds to the time point of 40 seconds of the charge / discharge suspension period after the end of the discharge period. Is not limited to this. The OCV measurement period for determining ΔOCV may be any period as long as the difference in ΔOCV during the charge / discharge suspension period after each charge / discharge cycle becomes clear.

以上が、第２実施形態における移行点を決定する診断装置の動作である。記憶部は、診断装置に上記の動作を行わせるプログラムを記憶いしている。 The above is the operation of the diagnostic device that determines the transition point in the second embodiment. The storage unit stores a program that causes the diagnostic device to perform the above operation.

なお、上記の実施形態では、使用中のリチウムイオン二次電池の容量支配極の移行点を判定する方法として、実験により電圧（参照ＯＣＶ）や電圧の上昇速度（ΔＯＣＶ）、即ち、基準となる数値（参照値）を予め求めておき、それを記憶部に記憶して、その参照値と実測値とを比較する方法を用いたが、それ以外の方法も可能である。 In the above embodiment, the voltage (reference OCV) and the voltage rise rate (ΔOCV), that is, the reference, are experimentally used as a method for determining the transition point of the capacity controlling electrode of the lithium ion secondary battery in use. A method was used in which a numerical value (reference value) was obtained in advance, stored in a storage unit, and the reference value was compared with the actually measured value, but other methods are also possible.

例えば、使用中のリチウムイオン二次電池の移行点を決定することもでき、第１実施形態のようにＯＣＶを用いる場合、［第１ステップ］所定の充放電サイクル回数の時に、放電期間後の１０分の充放電休止期間の１０分の時点でＯＣＶを測定し、［第２ステップ］最新の測定されたＯＣＶから所定の測定数だけ遡ったＯＣＶまでのそれぞれのＯＣＶ（過去の所定数のＯＣＶ）が、それらＯＣＶの平均値の所定の偏差内にあるか否かを判定し、［第３ステップ］過去の所定数のＯＣＶがそれらＯＣＶの平均値の所定の偏差内にある場合に、その中の最も古いＯＣＶを測定した時点（充放電サイクル回数）を、移行点と決定することもできる。第２実施形態のようにΔＯＣＶを用いる場合も、上記と同様に、使用中のリチウムイオン二次電池の移行点を決定することができる。なお、このような構成の場合、移行点が決定される時期が少し遅れることになる欠点はある。 For example, it is possible to determine the transition point of the lithium ion secondary battery in use, and when OCV is used as in the first embodiment, [1st step] at a predetermined number of charge / discharge cycles, after the discharge period. OCV is measured at 10 minutes of the 10-minute charge / discharge suspension period, and [2nd step] each OCV (previous predetermined number of OCVs) from the latest measured OCV to the OCV retroactive by a predetermined number of measurements. ) Is within a predetermined deviation of the average value of those OCVs, and [third step] if a predetermined number of OCVs in the past are within a predetermined deviation of the average value of those OCVs. The time point at which the oldest OCV is measured (number of charge / discharge cycles) can also be determined as a transition point. When ΔOCV is used as in the second embodiment, the transition point of the lithium ion secondary battery in use can be determined in the same manner as described above. In the case of such a configuration, there is a drawback that the time when the transition point is determined is slightly delayed.

次に、リチウムイオン二次電池のＥＯＬを予測するための構成（第３実施形態）について説明する。本発明では、リチウムイオン二次電池のＥＯＬを予測する際に、従来技術のようにリチウムイオン二次電池の使用開始時からの全ての測定値を用いるのではなく、本発明により求められた移行点より後の測定値を用いる。 Next, a configuration (third embodiment) for predicting the EOL of the lithium ion secondary battery will be described. In the present invention, when predicting the EOL of the lithium ion secondary battery, instead of using all the measured values from the start of use of the lithium ion secondary battery as in the prior art, the transition required by the present invention is used. Use the measured value after the point.

第３実施形態の診断装置は、ハードウェアの構成としては第１実施形態または第２実施形態の診断装置と同様であるが、測定部４は、移行点以降のリチウムイオン二次電池の所定の充放電サイクルの回の充電期間直後の可逆容量を測定あるいは推定する構成を備え、記憶部３は更に、リチウムイオン二次電池のＢＯＬ時の可逆容量（初期可逆容量）と、測定あるいは推定された可逆容量と、その充放電サイクルの回（累積充放電サイクル回数）とを記憶する構成を備え、比較部５の計算手段は更に、記憶部３に記憶されている初期可逆容量と測定あるいは推定された可逆容量とに基づいて容量維持率を計算する構成と、容量維持率と累積充放電サイクル回数との関係を関数にする構成とを備える。図７は、第３実施形態における診断装置の動作を示すフローチャートである。以下に、この診断装置の動作について、図７を参照して説明する。 The diagnostic device of the third embodiment has the same hardware configuration as the diagnostic device of the first embodiment or the second embodiment, but the measuring unit 4 is a predetermined lithium ion secondary battery after the transition point. It has a configuration for measuring or estimating the reversible capacity immediately after the charging period of each charge / discharge cycle, and the storage unit 3 is further measured or estimated as the reversible capacity (initial reversible capacity) at the time of BOL of the lithium ion secondary battery. It has a configuration for storing the reversible capacity and the number of charge / discharge cycles thereof (cumulative charge / discharge cycle count), and the calculation means of the comparison unit 5 is further measured or estimated as the initial reversible capacity stored in the storage unit 3. It includes a configuration in which the capacity retention rate is calculated based on the reversible capacity, and a configuration in which the relationship between the capacity retention rate and the number of cumulative charge / discharge cycles is used as a function. FIG. 7 is a flowchart showing the operation of the diagnostic device according to the third embodiment. The operation of this diagnostic device will be described below with reference to FIG. 7.

なお、第３実施形態は、移行点を決定する構成として第１実施形態または第２実施形態の構成を含むが、その構成については既に説明しているので、ここでは省略する。 The third embodiment includes the configuration of the first embodiment or the second embodiment as a configuration for determining a transition point, but the configuration has already been described and will be omitted here.

ステップＳ３．１において、入出力部２を介して、記憶部３に、リチウムイオン二次電池のＢＯＬ時の可逆容量（初期可逆容量）を記憶する。なお、ステップＳ３．１において、第１実施形態のステップＳ１．１または第２実施形態のステップＳ２．１において記憶されるデータも記憶されるが、図７では記載を省略している。 In step S3.1, the reversible capacity (initial reversible capacity) of the lithium ion secondary battery at the time of BOL is stored in the storage unit 3 via the input / output unit 2. In step S3.1, the data stored in step S1.1 of the first embodiment or step S2.1 of the second embodiment is also stored, but the description is omitted in FIG. 7.

ステップＳ３．２は、第１実施形態のステップＳ１．２～Ｓ１．４、または第２実施形態のステップＳ２．２～Ｓ２．５と同じステップを含む。即ち、可逆容量の測定あるいは推定の対象とされた充放電サイクルの時点が、容量支配極が一方の極から他方の極へ移行した時点、即ち、移行点であるか否かを判定する。ステップＳ３．２において、可逆容量の測定あるいは推定の対象とされた充放電サイクルの時点が移行点であると判定された場合、処理はステップＳ３．３へ進む。 Step S3.2 includes the same steps as steps S1.2 to S1.4 of the first embodiment or steps S2.2 to S2.5 of the second embodiment. That is, it is determined whether or not the time point of the charge / discharge cycle targeted for measurement or estimation of the reversible capacity is the time point at which the capacity controlling pole shifts from one pole to the other pole, that is, the transition point. If it is determined in step S3.2 that the time point of the charge / discharge cycle targeted for measurement or estimation of the reversible capacitance is the transition point, the process proceeds to step S3.3.

ステップＳ３．３において、制御部６は、測定部４を用いて、移行点以降の所定の充放電サイクルの回の充電期間直後の可逆容量を測定あるいは推定し、その測定あるいは推定を行った充放電サイクルの回（累積充放電サイクル回数）と測定あるいは推定された可逆容量とを関連付けて、記憶部３に記憶する。 In step S3.3, the control unit 6 measures or estimates the reversible capacity immediately after the charging period of a predetermined charge / discharge cycle after the transition point by using the measurement unit 4, and the measurement or estimation is performed. The number of discharge cycles (cumulative number of charge / discharge cycles) is associated with the measured or estimated reversible capacity and stored in the storage unit 3.

ステップＳ３．４において、制御部６は、比較部５の計算手段を用いて、記憶部３に記憶されている初期可逆容量と測定あるいは推定された可逆容量とに基づいて、それぞれの充放電サイクルの回（累積充放電サイクル回数）に関して、容量維持率を計算する。 In step S3.4, the control unit 6 uses the calculation means of the comparison unit 5 to charge and discharge each charge / discharge cycle based on the initial reversible capacity stored in the storage unit 3 and the measured or estimated reversible capacity. The capacity retention rate is calculated for the number of times (cumulative charge / discharge cycles).

ステップＳ３．５において、制御部６は、所定数の累積充放電サイクル回数と容量維持率との組が揃った時点で、それら複数の累積充放電サイクル回数と複数の容量維持率との関係性に最も近似する関数（一次関数）、Ｙ＝ａＸ＋ｂ（Ｙは容量維持率、Ｘは累積充放電サイクル回数）を導出する。この関数を求める際には回帰分析を用いることができるが、回帰分析の詳細については周知であるので、ここでは説明を省略する。 In step S3.5, when the set of the predetermined number of cumulative charge / discharge cycles and the capacity retention rate is prepared, the control unit 6 has a relationship between the plurality of cumulative charge / discharge cycles and the plurality of capacity retention rates. A function (linear function) that most closely resembles to, Y = aX + b (Y is the capacity retention rate, X is the number of cumulative charge / discharge cycles) is derived. Regression analysis can be used to obtain this function, but since the details of regression analysis are well known, the description thereof will be omitted here.

ステップＳ３．６において、制御部６は、ステップＳ３．５で得られた関数を用いて、リチウムイオン二次電池のＥＯＬ時の累積充放電サイクル回数を求める。この実施形態では、ＥＯＬは、容量維持率８０％を維持できなくなった時点としている。従って、導出した一次関数、Ｙ＝ａＸ＋ｂ、のＹ＝８０、ａ＝定数、ｂ＝１００として、ＥＯＬ時（容量維持率が８０％になる時点）の累積充放電サイクル回数を求めることができる。 In step S3.6, the control unit 6 obtains the cumulative number of charge / discharge cycles during EOL of the lithium ion secondary battery by using the function obtained in step S3.5. In this embodiment, the EOL is the time when the capacity retention rate of 80% cannot be maintained. Therefore, the cumulative number of charge / discharge cycles during EOL (when the capacity retention rate reaches 80%) can be obtained by setting the derived linear function, Y = aX + b, Y = 80, a = constant, and b = 100.

なお、第３実施形態では、移行点以降の所定の充放電サイクルの回の可逆容量を測定あるいは推定する構成としたが、リチウムイオン二次電池のＢＯＬの時点から可逆容量を測定する構成としてもよく、その場合は、複数の累積充放電サイクル回数と複数の容量維持率との関係性に最も近似する関数を導出する際に、単に、移行点以降に測定あるいは推定された可逆容量を用いるように構成すればよい。 In the third embodiment, the reversible capacity is measured or estimated at a predetermined charge / discharge cycle after the transition point, but the reversible capacity may be measured from the time of BOL of the lithium ion secondary battery. Often, in that case, simply use the reversible capacitance measured or estimated after the transition point when deriving the function that most closely resembles the relationship between the number of cumulative charge / discharge cycles and the capacitance retention. It may be configured as.

以上が、第３実施形態におけるリチウムイオン二次電池のＥＯＬを予測する診断装置の動作である。記憶部は、診断装置に上記の動作を行わせるプログラムを記憶している。 The above is the operation of the diagnostic device for predicting the EOL of the lithium ion secondary battery in the third embodiment. The storage unit stores a program that causes the diagnostic device to perform the above operation.

以下では、図８および図９を参照して、第３実施形態により求められるＥＯＬと従来技術により求められるＥＯＬとの差異を明確にするための説明を行う。 In the following, with reference to FIGS. 8 and 9, a description will be given to clarify the difference between the EOL required by the third embodiment and the EOL required by the prior art.

図８および図９は、リチウムイオン二次電池の充電を２５℃で１Ｃで行った後、０．２Ｃで放電した際の容量維持率と、充放電サイクル回数との関係を示すグラフである。グラフでは、縦軸が容量維持率（％）を示し、リチウムイオン二次電池を最初に使用する時の満充電の状態での容量維持率を１００％としている。横軸は充放電サイクルの回数を示すが、回数は、回数の平方根として示されている。例えば、グラフの横軸の２０は、４００回を表す。 8 and 9 are graphs showing the relationship between the capacity retention rate and the number of charge / discharge cycles when the lithium ion secondary battery is charged at 25 ° C. at 1 C and then discharged at 0.2 C. In the graph, the vertical axis indicates the capacity retention rate (%), and the capacity retention rate in a fully charged state when the lithium ion secondary battery is first used is set to 100%. The horizontal axis shows the number of charge / discharge cycles, and the number of times is shown as the square root of the number of times. For example, 20 on the horizontal axis of the graph represents 400 times.

図８および図９のグラフにおいて、「〇」で示す複数の点のそれぞれは、実際に測定した点（以下、測定点という）である。例えば、図８のグラフの左側から２つ目の〇は、充放電サイクル回数が約２５０回のときの容量維持率が約９９％であったことを示し、左側から３つ目の〇は、充放電サイクル回数が約５００回のときの容量維持率が約９７．５％であったことを示す。 In the graphs of FIGS. 8 and 9, each of the plurality of points indicated by “◯” is a point actually measured (hereinafter referred to as a measurement point). For example, the second circle from the left side of the graph in FIG. 8 indicates that the capacity retention rate was about 99% when the number of charge / discharge cycles was about 250, and the third circle from the left side is. It is shown that the capacity retention rate was about 97.5% when the number of charge / discharge cycles was about 500.

図８のグラフの点線の直線は、サイクル回数が０の時点からの全ての測定点に基づいて導き出した、それら測定点の関係性に最も近似する関数を表すものである。このように、ＢＯＬからの全ての測定点に基づいて関数を導出する手法が、上記の「背景技術」に記載した従来技術の手法である。この従来技術の手法で求めた関数はｙ＝－０．１７ｘ＋１００であった。この関数と測定点との間での決定係数（Ｒ２）は０．８４３７であった。 The dotted straight line in the graph of FIG. 8 represents the function most closely related to the relationship between the measurement points, which is derived based on all the measurement points from the time when the number of cycles is 0. As described above, the method of deriving the function based on all the measurement points from the BOL is the method of the prior art described in the above-mentioned "background technique". The function obtained by this conventional method was y = −0.17x + 100. The coefficient of determination (R 2 ) between this function and the measurement point was 0.8437.

このｙ＝－０．１７ｘ＋１００という関数に基づくと、容量維持率が８０％になる時点、即ち、規定されたＥＯＬを迎える時点は、充放電サイクル回数が６４００回（グラフ横軸の８０）を越えたかなり先の時点と予測される。 Based on this function of y = -0.17x + 100, the number of charge / discharge cycles exceeds 6400 (80 on the horizontal axis of the graph) when the capacity retention rate reaches 80%, that is, when the specified EOL is reached. It is expected to be a long time ago.

図９では、図８に記載している測定点のうち、本発明に従って求められたリチウムイオン二次電池の挙動が変化する点（移行点）以降の複数の測定点を記載している。この例では、リチウムイオン二次電池の可逆容量の減少の傾向の移行点は、充放電サイクル回数が約４００回のときとされている。従って、図８に示す複数の測定点のうち、左側の２つの測定点は、充放電サイクル回数が４００回になる以前のものであので、図９には記載されていない。 In FIG. 9, among the measurement points shown in FIG. 8, a plurality of measurement points after the point at which the behavior of the lithium ion secondary battery changes (transition point) determined according to the present invention are shown. In this example, the transition point of the tendency of the reversible capacity of the lithium ion secondary battery to decrease is when the number of charge / discharge cycles is about 400. Therefore, of the plurality of measurement points shown in FIG. 8, the two measurement points on the left side are those before the number of charge / discharge cycles reaches 400, and are not shown in FIG.

図９の点線の直線は、図９に示す複数の測定点に基づいて導き出した、それら測定点の関係性に最も近似する関数を表すものである。この関数はｙ＝－０．３３２１ｘ＋１０５．０２であり、この関数と、移行点以降の複数の測定点との間での決定係数（Ｒ２）は０．９８０９であった。 The dotted straight line in FIG. 9 represents a function that is derived based on the plurality of measurement points shown in FIG. 9 and that most closely resembles the relationship between these measurement points. This function was y = −0.3321x + 105.02, and the coefficient of determination ( R2 ) between this function and the plurality of measurement points after the transition point was 0.9809.

このｙ＝－０．３３２１ｘ＋１０５．０２という関数に基づくと、容量維持率が８０％になる時点（グラフでは「●」で示す）、即ち、規定されたＥＯＬを迎える時点は、充放電サイクル回数が約５６００回の時点と予測される。 Based on this function of y = -0.3321x + 105.02, the number of charge / discharge cycles is the time when the capacity retention rate reaches 80% (indicated by "●" in the graph), that is, when the specified EOL is reached. It is estimated to be about 5600 times.

上記の決定係数からも判断できるように、リチウムイオン二次電池の可逆容量の減少の傾向の移行点以降の挙動については、本発明の技術により求めた関数のほうが、実際の挙動をより良く表している。従って、従来技術で求められたＥＯＬ（充放電サイクル回数が６４００回を越えたかなり先の時点）よりも、本発明の技術により求められたＥＯＬ（充放電サイクル回数が５６００回の時点）のほうが、理論的には、実際のＥＯＬに近い。 As can be judged from the above coefficient of determination, the function obtained by the technique of the present invention better represents the actual behavior of the behavior after the transition point of the tendency of the reversible capacity of the lithium ion secondary battery to decrease. ing. Therefore, the EOL (at the time when the number of charge / discharge cycles is 5600) obtained by the technique of the present invention is higher than the EOL (at a time when the number of charge / discharge cycles exceeds 6400 times) obtained by the prior art. , Theoretically, it is close to the actual EOL.

なお、ｙ＝－０．３３２１ｘ＋１０５．０２という関数に基づくと、充放電サイクル回数が０回のときの容量維持率が約１０５％となるが（図９のグラフでは「●」で示す）、この１０５％という容量維持率は、負極の不可逆容量に基づいて決定される可逆容量に対応するものである。これについては、上記の「発明が解決しようとする課題」でも説明したように、移行点より前のリチウムイオン二次電池の可逆容量に関しては、負極よりも正極の影響のほうが大きい（正極の可逆容量のほうが少ない）。従って、移行点より前では、たとえ負極の不可逆容量に基づいて決定される可逆容量が、正極の不可逆容量に基づいて決定される可逆容量より多くとも、正極の不可逆容量に基づいて決定される可逆容量が実際に使用できる可逆容量となる。即ち、充放電サイクル回数が０回のときの実際の可逆容量は、図８に示す容量維持率１００％に対応する可逆容量となる。 Based on the function y = -0.3321x + 105.02, the capacity retention rate is about 105% when the number of charge / discharge cycles is 0 (indicated by "●" in the graph of FIG. 9). The capacity retention rate of 105% corresponds to the reversible capacity determined based on the irreversible capacity of the negative electrode. Regarding this, as explained in the above-mentioned "Problems to be solved by the invention", the influence of the positive electrode is larger than that of the negative electrode on the reversible capacity of the lithium ion secondary battery before the transition point (reversible of the positive electrode). The capacity is smaller). Therefore, prior to the transition point, even if the reversible capacity determined based on the irreversible capacity of the negative electrode is greater than the reversible capacity determined based on the irreversible capacity of the positive electrode, the reversible capacity determined based on the irreversible capacity of the positive electrode. The capacity is the reversible capacity that can actually be used. That is, the actual reversible capacity when the number of charge / discharge cycles is 0 is the reversible capacity corresponding to the capacity retention rate of 100% shown in FIG.

上記では第１ないし第２実施形態について説明したが、更に別の実施形態では、リチウムイオン二次電池を良好な状態に保つために、第１実施形態または第２実施形態の診断装置を応用することができる。以下では第１実施形態を用いた応用例について説明する。 Although the first to second embodiments have been described above, in still another embodiment, the diagnostic apparatus of the first embodiment or the second embodiment is applied in order to keep the lithium ion secondary battery in a good state. be able to. Hereinafter, an application example using the first embodiment will be described.

リチウムイオン二次電池の使用環境を制御する制御装置が、リチウムイオン二次電池を良好な状態に保つためには、移行点の前後で、即ち、容量支配極が正極である期間と容量支配極が負極である期間とで、異なる制御、例えば、充放電の際の電流や温度などを変更する制御を行う必要がある。そのような制御装置において、本発明の第１実施形態または第２実施形態を応用することで、移行点を決定することができるので、例えば、第１実施形態のステップＳ１．４または第２実施形態のステップＳ２．５においてＮｏの場合には、一方の極を主に考慮する制御を行い、第１実施形態のステップＳ１．４または第２実施形態のステップＳ２．５においてＹｅｓの場合には、他方の極を主に考慮する制御を行うように、制御装置を構成することができる。 In order for the control device that controls the usage environment of the lithium ion secondary battery to keep the lithium ion secondary battery in good condition, it is before and after the transition point, that is, the period during which the capacity controlling electrode is the positive electrode and the capacity controlling electrode. It is necessary to perform different control, for example, control to change the current and temperature at the time of charging / discharging, depending on the period in which is the negative electrode. In such a control device, the transition point can be determined by applying the first embodiment or the second embodiment of the present invention. Therefore, for example, step S1.4 or the second embodiment of the first embodiment. In the case of No in step S2.5 of the embodiment, control is performed mainly considering one pole, and in the case of Yes in step S1.4 of the first embodiment or step S2.5 of the second embodiment, control is performed. , The control device can be configured to perform control that primarily considers the other pole.

また、上記の実施形態では、リチウムイオン二次電池を例として用いたが、本発明は、他の電池にも適用できる。詳細には、本発明は、可逆容量の減少の主因となる正極および負極の劣化を伴う再充電可能な電池であって、使用開始後の初期には正極と負極とのうちの一方の極のほうが他方の極よりも劣化が多いため、一方の極が可逆容量の減少に大きく関与するが、一方の極よりも他方の極のほうが劣化が速く、一方の極および他方の極の双方の劣化が進むと、或る時点からは一方の極の劣化よりも他方の極の劣化のほうが多くなり、他方の極が可逆容量の減少に大きく関与するという特性を有する電池に、適用することができる。 Further, in the above embodiment, the lithium ion secondary battery is used as an example, but the present invention can be applied to other batteries. Specifically, the present invention is a rechargeable battery with deterioration of the positive and negative electrodes, which is the main cause of the decrease in reversible capacity, and the initial period after the start of use is that of one of the positive and negative electrodes. One pole contributes significantly to the reduction of reversible capacitance because it deteriorates more than the other pole, but the other pole deteriorates faster than one pole, and both one pole and the other pole deteriorate. As the process progresses, the deterioration of the other electrode is greater than the deterioration of one electrode from a certain point in time, and the other electrode can be applied to a battery having a characteristic that it is greatly involved in the reduction of the reversible capacity. ..

本発明は、上記のような特性を有する電池の状態を診断するために使用することができる。 The present invention can be used to diagnose the condition of a battery having the above characteristics.

１ 診断装置
２ 入出力部
３ 記憶部
４ 測定部
５ 比較部
６ 制御部 1 Diagnostic device 2 Input / output unit 3 Storage unit 4 Measurement unit 5 Comparison unit 6 Control unit

Claims (11)

正極と負極を有する二次電池の可逆容量を決定する容量支配極を検出する二次電池の診断装置であって、前記二次電池の診断装置は、
正極の可逆容量と負極の可逆容量のいずれが大きいか判定することにより二次電池の可逆容量を決定する容量支配極を検出する検出手段を有する、
二次電池の診断装置において、
前記検出手段は、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性に基づいて、正極の可逆容量と負極の可逆容量のいずれが大きいか判定する、
二次電池の診断装置。 A secondary battery diagnostic device that detects a capacity-dominant electrode that determines the reversible capacity of a secondary battery having a positive electrode and a negative electrode, and the secondary battery diagnostic device is
It has a detecting means for detecting a capacity-dominant electrode that determines the reversible capacity of a secondary battery by determining which of the reversible capacity of the positive electrode and the reversible capacity of the negative electrode is larger.
In the diagnostic device of the secondary battery
The detection means reversible capacity of the positive electrode and reversible of the negative electrode based on the voltage characteristics of the open circuit voltage (OCV) of the secondary battery after the discharge is stopped in the charge / discharge cycle of the secondary battery and during the charge / discharge stop period. Determine which of the capacities is larger,
Diagnostic device for secondary batteries. 請求項1に記載の二次電池の診断装置において、
前記検出手段は、
前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性として、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)を測定する測定部と、
正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)の値として予め設定されている電圧値と、前記測定部において測定された、前記二次電池の充放電サイクルの放電停止後の所定期間経過後の開回路電圧(ＯＣＶ)を比較する比較部とを含む、
二次電池の診断装置。 In the secondary battery diagnostic device according to claim 1 ,
The detection means
The voltage characteristic of the open circuit voltage (OCV) of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period is a predetermined period after the discharge stop of the charge / discharge cycle of the secondary battery. A measuring unit that measures the open circuit voltage (OCV) after the lapse of time,
A voltage value preset as a value of the open circuit voltage (OCV) after a predetermined period has elapsed after the discharge is stopped in the charge / discharge cycle of the secondary battery when the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match. A comparison unit for comparing the open circuit voltage (OCV) measured in the measurement unit after a predetermined period of time has elapsed after the discharge of the charge / discharge cycle of the secondary battery is stopped is included.
Diagnostic device for secondary batteries. 請求項1に記載の二次電池の診断装置において、
前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性は、前記二次電池の充放電サイクルの放電停止後の所定期間内の開回路電圧(ＯＣＶ)の回復の速さであり、
前記検出手段は、
前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値を求める手段と、
前記二次電池が劣化する過程で、正極の可逆容量と負極の可逆容量が一致したときの前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値として予め設定されている速さの値と、求められた前記二次電池の充放電サイクルの放電停止後の所定期間内の前記開回路電圧(ＯＣＶ)の回復の速さの値とを比較する手段とを含む、
二次電池の診断装置。 In the secondary battery diagnostic device according to claim 1 ,
The voltage characteristic of the open circuit voltage (OCV) of the secondary battery after the discharge stop of the charge / discharge cycle of the secondary battery and during the charge / discharge stop period is a predetermined period after the discharge stop of the charge / discharge cycle of the secondary battery. The speed of recovery of the open circuit voltage (OCV) in
The detection means
A means for obtaining the value of the recovery speed of the open circuit voltage (OCV) within a predetermined period after the discharge of the charge / discharge cycle of the secondary battery is stopped, and
Recovery of the open circuit voltage (OCV) within a predetermined period after the discharge of the charge / discharge cycle of the secondary battery is stopped when the reversible capacity of the positive electrode and the reversible capacity of the negative electrode match in the process of deterioration of the secondary battery. The value of the speed preset as the value of the speed of, and the speed of recovery of the open circuit voltage (OCV) within a predetermined period after the discharge of the obtained charge / discharge cycle of the secondary battery is stopped. Including means to compare values with,
Diagnostic device for secondary batteries. 請求項１～３のいずれか一項に記載の二次電池の診断装置において、更に、
前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を判定する判定手段を有する、
二次電池の診断装置。 In the secondary battery diagnostic device according to any one of claims 1 to 3 , further
It has a determination means for determining a transition point where the capacity controlling electrode that determines the reversible capacity of the secondary battery has shifted from one of the positive electrode and the negative electrode to the other in the process of deterioration of the secondary battery.
Diagnostic device for secondary batteries. 請求項４に記載の二次電池の診断装置において、前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点を、累積充放電サイクル回数により示す、二次電池の診断装置。 In the secondary battery diagnostic device according to claim 4 , in the process of deterioration of the secondary battery, the capacity controlling electrode that determines the reversible capacity of the secondary battery shifts from one of the positive electrode and the negative electrode to the other. A secondary battery diagnostic device that indicates the transition point that has been achieved by the cumulative number of charge / discharge cycles. 請求項４又は５に記載の二次電池の診断装置において、更に、
前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した移行点以降の、前記二次電池の劣化状態の計時変化を検出して、前記二次電池の寿命性能を予測する寿命予測手段を有する、
二次電池の診断装置。 In the secondary battery diagnostic apparatus according to claim 4 or 5 , further
In the process of deterioration of the secondary battery, the deterioration state of the secondary battery after the transition point where the capacity controlling electrode that determines the reversible capacity of the secondary battery shifts from one of the positive electrode and the negative electrode to the other. It has a life prediction means for detecting a time change and predicting the life performance of the secondary battery.
Diagnostic device for secondary batteries. 請求項４～６のいずれか一項に記載の二次電池の診断装置を含む二次電池制御システムにおいて、
前記二次電池が劣化する過程で、前記二次電池の可逆容量を決定する容量支配極が、正極と負極のいずれか一方から他方へ移行した時点に、前記二次電池に対する制御を変更する制御手段を有する、
二次電池制御システム。 In the secondary battery control system including the diagnostic device for the secondary battery according to any one of claims 4 to 6 .
Control to change the control of the secondary battery when the capacity controlling electrode that determines the reversible capacity of the secondary battery shifts from one of the positive electrode and the negative electrode to the other in the process of deterioration of the secondary battery. Have a means,
Secondary battery control system. 請求項１～６のいずれか一項に記載の二次電池の診断装置を含む二次電池の充電装置。 A secondary battery charging device including the secondary battery diagnostic device according to any one of claims 1 to 6 . 正極と負極を有する二次電池の可逆容量を決定する容量支配極を検出する二次電池の診断方法であって、前記二次電池の診断方法は、
正極の可逆容量と負極の可逆容量のいずれが大きいか判定することにより二次電池の可逆容量を決定する容量支配極を検出する検出ステップを有する、
二次電池の診断方法において、
前記検出ステップは、前記二次電池の充放電サイクルの放電停止後であり充放電停止期間中の二次電池の開回路電圧(ＯＣＶ)の電圧特性に基づいて、正極の可逆容量と負極の可逆容量のいずれが大きいか判定する、
二次電池の診断方法。 A method for diagnosing a secondary battery that detects a capacity-dominant electrode that determines the reversible capacity of a secondary battery having a positive electrode and a negative electrode, the method for diagnosing the secondary battery is.
It has a detection step of detecting a capacity-dominant electrode that determines the reversible capacity of a secondary battery by determining which of the reversible capacity of the positive electrode and the reversible capacity of the negative electrode is larger.
In the method of diagnosing a secondary battery
The detection step is the reversible capacity of the positive electrode and the reversible of the negative electrode based on the voltage characteristics of the open circuit voltage (OCV) of the secondary battery after the discharge is stopped in the charge / discharge cycle of the secondary battery and during the charge / discharge stop period. Determine which of the capacities is larger,
How to diagnose a secondary battery . 請求項９に記載の方法を実行するためのプログラム。 A program for performing the method according to claim 9 . 請求項９に記載の方法を実行するためのプログラムを記録した記録媒体。 A recording medium on which a program for executing the method according to claim 9 is recorded.
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