JP2019153529A - Secondary battery system - Google Patents
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Classifications
-
- 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
Abstract
Description
本開示は、二次電池システムに関する。 The present disclosure relates to a secondary battery system.
高電圧で充放電するために、直列に接続されている複数の単電池を有する二次電池システムが用いられている。 In order to charge and discharge at a high voltage, a secondary battery system having a plurality of single cells connected in series is used.
このような二次電池システムでは、二次電池システムを構成する複数の単電池の間で充電状態（ＳＯＣ：Ｓｔａｔｅ Ｏｆ Ｃｈａｒｇｅ）に差（バラツキ）が生じると、利用可能な電気量が低下することが知られている。 In such a secondary battery system, if a difference (variation) occurs in the state of charge (SOC) among a plurality of single cells constituting the secondary battery system, the amount of available electricity decreases. It has been known.
例えば、図１は、複数の単電池の間での充電状態のバラツキによる利用可能な電気量の低下を示すイメージ図である。図１（ａ）は、複数の単電池の間での充電状態にバラツキがない場合を示すイメージ図であり、図１（ｂ）は、複数の単電池の間での充電状態にバラツキがある場合（例えば、ＳＯＣズレした単電池が一つ存在する場合）を示すイメージ図である。このように、図１（ａ）と図１（ｂ）とを比較すると、複数の単電池の間での充電状態にバラツキがあると、利用可能な電気量が低下していることが分かる。 For example, FIG. 1 is an image diagram illustrating a decrease in the amount of electricity that can be used due to variations in the state of charge among a plurality of single cells. Fig.1 (a) is an image figure which shows the case where there is no dispersion | variation in the charge condition between several single cells, FIG.1 (b) is a case where there exists dispersion | variation in the charge state between several single cells. It is an image figure which shows (for example, when the single cell which SOC shifted | deviated exists). Thus, comparing FIG. 1 (a) and FIG. 1 (b), it can be seen that the amount of available electricity is reduced if there is variation in the state of charge among a plurality of single cells.
このような問題に対して、特許文献１では、定置用蓄電池を構成する複数のニッケル水素二次電池間の充電状態のバラツキによる定置用蓄電池の性能低下を抑制できる定置用蓄電システムを提供している。ここで、この特許文献１のシステムでは、ニッケル水素二次電池の過充電の際の水の電気分解反応を利用して、複数のニッケル水素二次電池間の充電状態のバラツキを解消している。 With respect to such a problem, Patent Document 1 provides a stationary power storage system that can suppress degradation of the performance of a stationary storage battery due to variation in the state of charge between a plurality of nickel metal hydride secondary batteries constituting the stationary storage battery. Yes. Here, in the system of this patent document 1, the variation in the charge state between several nickel-hydrogen secondary batteries is eliminated using the electrolysis reaction of the water at the time of the overcharge of a nickel-hydrogen secondary battery. .
特許文献１のシステムは、ニッケル水素二次電池の過充電の際の水の電気分解反応を利用して、複数のニッケル水素二次電池間の充電状態のバラツキを解消しており、したがって、複数の単電池を有する全固体リチウム二次電池システムに適用できるものではなかった。 The system of Patent Document 1 uses a water electrolysis reaction during overcharging of a nickel metal hydride secondary battery to eliminate variation in the state of charge between the plurality of nickel metal hydride secondary batteries. It was not applicable to an all-solid lithium secondary battery system having a single cell.
なお、特許文献２では、固体電解質層と活物質層との界面に生じる皮膜（ＳＥＩ）に起因する内部抵抗の増加を低減するために、一つの単電池又は並列に接続されている単電池に対して、ＳＯＣが０％よりも低い状態になるまで放電させるシステムが開示されている。 In Patent Document 2, in order to reduce an increase in internal resistance due to a film (SEI) generated at the interface between the solid electrolyte layer and the active material layer, a single cell or a single cell connected in parallel is used. On the other hand, a system for discharging until the SOC becomes lower than 0% is disclosed.
本開示では、直列に接続されている複数の全固体リチウム二次単電池の間の充電状態のバラツキを減少させる又は解消することができる、二次電池システムを提供する。 The present disclosure provides a secondary battery system that can reduce or eliminate variations in the state of charge between a plurality of all-solid lithium secondary cells connected in series.
本開示の本発明者らは、以下の手段により、上記課題を解決できることを見出した。
直列に接続されている複数の単電池、
前記複数の単電池の全体の電圧値、電流値、及び温度をそれぞれ取得する電圧値取得部、電流値取得部、及び温度取得部、
前記電圧値、前記電流値、及び前記温度から、前記複数の単電池の全体の実放電容量を算出する演算部、並びに
前記全体の実放電容量が所定の値よりも小さくなったときに、前記複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ前記不可逆反応の終了電圧よりも大きい電圧になるように、前記複数の単電池の全体を放電させる、放電制御部を有し、かつ
前記単電池が、全固体リチウム二次単電池である、
二次電池システム。
The inventors of the present disclosure have found that the above problems can be solved by the following means.
Multiple cells connected in series,
A voltage value acquisition unit, a current value acquisition unit, and a temperature acquisition unit that respectively acquire the overall voltage value, current value, and temperature of the plurality of single cells,
From the voltage value, the current value, and the temperature, a calculation unit that calculates an overall actual discharge capacity of the plurality of single cells, and when the overall actual discharge capacity becomes smaller than a predetermined value, Discharging the whole of the plurality of unit cells so that the voltage of at least one unit cell of the plurality of unit cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. Having a control unit, and the unit cell is an all-solid lithium secondary unit cell,
Secondary battery system.
本開示の二次電池システムによれば、直列に接続されている複数の単電池の間の充電状態のバラツキを減少させる又は解消することができる。 According to the secondary battery system of the present disclosure, it is possible to reduce or eliminate variations in the state of charge between a plurality of single cells connected in series.
以下、本開示の実施形態について詳細に説明する。なお、本開示は、以下の実施形態に限定されるものではなく、本開示の要旨の範囲内で種々変形して実施できる。 Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure.
≪二次電池システム及び二次電池制御方法≫
本開示の二次電池システムは、
直列に接続されている複数の単電池、
複数の単電池の全体の電圧値、電流値、及び温度をそれぞれ取得する電圧値取得部、電流値取得部、及び温度取得部、
電圧値、電流値、及び温度から、複数の単電池の全体の実放電容量を算出する演算部、並びに
全体の実放電容量が所定の値よりも小さくなったときに、複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させる、放電制御部を有し、かつ
単電池が、全固体リチウム二次単電池である。
≪Secondary battery system and secondary battery control method≫
The secondary battery system of the present disclosure is
Multiple cells connected in series,
A voltage value acquisition unit, a current value acquisition unit, and a temperature acquisition unit that respectively acquire the overall voltage value, current value, and temperature of a plurality of single cells,
A calculation unit that calculates the overall actual discharge capacity of the plurality of single cells from the voltage value, current value, and temperature, and when the entire actual discharge capacity becomes smaller than a predetermined value, A discharge control unit that discharges all of the plurality of unit cells so that the voltage of at least one unit cell of the first cell is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. The battery is an all solid lithium secondary cell.
なお、本開示に関して、充電状態（ＳＯＣ：Ｓｔａｔｅ Ｏｆ Ｃｈａｒｇｅ）とは、二次電池に充電されている電気量を１００分率で表わす値であって、二次電池が満充電のときの電気量を１００％とし、かつ二次電池が完全に放電されているときの電気量を０％とする値である。 In addition, regarding the present disclosure, the state of charge (SOC) is a value representing the amount of electricity charged in the secondary battery in terms of 100%, and the amount of electricity when the secondary battery is fully charged. Is 100%, and the amount of electricity when the secondary battery is completely discharged is 0%.
本開示はまた、二次電池の制御方法を提供することができる。 The present disclosure can also provide a method for controlling a secondary battery.
本開示の二次電池制御方法は、
直列に接続されている複数の単電池の全体の電圧値、電流値、及び温度をそれぞれ取得し、
電圧値、電流値、及び温度から、複数の単電池の全体の実放電容量を算出し、そして
全体の実放電容量が所定の値よりも小さくなったときに、複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させる。なお、単電池が、全固体リチウム二次単電池である。
The secondary battery control method of the present disclosure includes:
Obtain the overall voltage value, current value, and temperature of each of the multiple cells connected in series,
The total actual discharge capacity of the plurality of single cells is calculated from the voltage value, current value, and temperature, and when the total actual discharge capacity becomes smaller than a predetermined value, at least one of the plurality of single cells is calculated. The whole of the plurality of single cells is discharged so that the voltage of one single cell is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. The unit cell is an all-solid lithium secondary unit cell.
図２は、本開示の二次電池システムの構成の一形態を示す概略図である。図２に示されているように、本開示の二次電池システム１０は、直列に接続されている複数の単電池１ａ、１ｂ、…、１ｘ、及び１ｙを含む全固体リチウム二次電池１、全固体リチウム二次電池１の全体の電圧値Ｖ、電流値Ｉ、及び温度Ｔをそれぞれ取得する電圧値取得部２、電流値取得部３、及び温度取得部４、電圧値Ｖ、電流値Ｉ、及び温度Ｔから、全体の実放電容量Ｑを算出する演算部５、並びに放電制御部６を有する。ここで、放電制御部６は、全体の実放電容量Ｑが所定の値よりも小さくなったときに、全固体リチウム二次電池１のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池１ａ、１ｂ、…、１ｘ、及び１ｙの全体（すなわち、全固体リチウム二次電池１）を放電させる。 FIG. 2 is a schematic diagram illustrating one form of the configuration of the secondary battery system of the present disclosure. As shown in FIG. 2, the secondary battery system 10 of the present disclosure includes an all-solid lithium secondary battery 1 including a plurality of single cells 1a, 1b,..., 1x, and 1y connected in series. The voltage value acquisition unit 2, the current value acquisition unit 3, and the temperature acquisition unit 4 that acquire the entire voltage value V, current value I, and temperature T of the all-solid-state lithium secondary battery 1, respectively, the voltage value V, the current value I , And a temperature T, a calculation unit 5 for calculating the entire actual discharge capacity Q, and a discharge control unit 6 are provided. Here, when the overall actual discharge capacity Q becomes smaller than a predetermined value, the discharge controller 6 determines that the voltage of at least one unit cell of the all-solid lithium secondary battery 1 is the starting voltage of the irreversible reaction. The whole of the plurality of single cells 1a, 1b,..., 1x, and 1y (that is, all-solid lithium secondary battery 1) is discharged so that the voltage is higher than the end voltage of the irreversible reaction.
本開示のシステムでは、単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ当該不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を通常放電電圧下限値よりも有意に低い電圧まで放電させる。 In the system of the present disclosure, the entire plurality of single cells are usually set so that the voltage of at least one of the single cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. Discharge to a voltage significantly lower than the lower limit of the discharge voltage.
例えば、図２において、スイッチ７をオンにし、スイッチ８をオフにして、全固体リチウム二次電池１を外部短絡させることによって、直列に接続されている複数の単電池１ａ、１ｂ、…、１ｘ、及び１ｙのうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池１ａ、１ｂ、…、１ｘ、及び１ｙの全体（すなわち、全固体リチウム二次電池１）を放電させることができる。 For example, in FIG. 2, the switch 7 is turned on, the switch 8 is turned off, and the all solid lithium secondary battery 1 is externally short-circuited, whereby a plurality of unit cells 1a, 1b,. , And 1y, the plurality of single cells 1a, 1b,. (That is, the all-solid lithium secondary battery 1) can be discharged.
本開示において、外部短絡とは、全固体リチウム二次電池の正極活物質層及び負極活物質層を、外部回路を通じて短絡させることをいう。例えば、図２において、スイッチ７をオンにし、スイッチ８をオフにする場合の回路を外部回路といい、この回路を通じて全固体リチウム二次電池１を短絡させることは、外部短絡といえる。また、このような外部回路は、抵抗を有することが好ましい。例えば、このような外部回路は、図２に示されているようにして、抵抗９を有することが好ましい。なお、図２において、スイッチ７をオフにし、スイッチ８をオンにする場合の回路が、通常の放電回路である。 In the present disclosure, the external short circuit means that the positive electrode active material layer and the negative electrode active material layer of the all-solid lithium secondary battery are short-circuited through an external circuit. For example, in FIG. 2, a circuit when the switch 7 is turned on and the switch 8 is turned off is called an external circuit, and shorting the all-solid lithium secondary battery 1 through this circuit can be called an external short circuit. Such an external circuit preferably has a resistance. For example, such an external circuit preferably has a resistor 9 as shown in FIG. In FIG. 2, the circuit when the switch 7 is turned off and the switch 8 is turned on is a normal discharge circuit.
ただし、本開示のシステムでは、複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させるために、上述した外部短絡のほか、放電を促進するための他の電源を有していてもよい。 However, in the system of the present disclosure, the voltage of at least one of the plurality of single cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. In order to discharge the whole, in addition to the external short circuit described above, another power source for promoting discharge may be provided.
上述したように、直列に接続されている複数の単電池の間での充電状態のバラツキによって、利用可能な電気量が低下する可能性がある。これに関して、図２に示されているように、直列に接続されている二つの単電池１ａ及び１ｂの間で充電状態のバラツキが生じている場合について、説明する。仮に、単電池１ａの充電状態が１００％であり、単電池１ｂの充電状態が９０％である場合、単電池１ｂは、放電しきって、充電状態が０％になると、それ以上は電池として放電できないため、単電池１ａの充電状態１０％の放電容量が使い切れず、残留することとなる。 As described above, there is a possibility that the available amount of electricity may decrease due to variations in the state of charge among the plurality of single cells connected in series. In this regard, as shown in FIG. 2, a case will be described where there is a variation in the state of charge between the two unit cells 1 a and 1 b connected in series. If the state of charge of the unit cell 1a is 100% and the state of charge of the unit cell 1b is 90%, the unit cell 1b is completely discharged, and when the state of charge becomes 0%, the battery is further discharged as a battery. As a result, the discharge capacity of 10% charged state of the unit cell 1a cannot be used up and remains.
これに対して、本開示の二次電池システムでのように、全固体リチウム二次電池１に対して積極的に放電制御を行う（例えば、全固体リチウム二次電池１の通常放電電圧下限値よりも有意に低い電圧まで放電させる）と、単電池１ｂに放電電流が流れ始める現象が起きる。この充電状態が低い単電池１ｂがＳＯＣ０％まで放電した段階（通常使用可能な電池内部の可逆反応が終了した状態）から、更に放電電流が流れる現象は、単電池１ｂにおける不可逆反応によるものと考えられる。そこで、本開示は、単電池１ｂの電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池１ａ、１ｂ、…、１ｘ、及び１ｙの全体（すなわち、全固体リチウム二次電池１）を放電させることによって、充電状態が相対的に大きい単電池１ａの残留された充電状態１０％の量を減らすことができる。すなわち、直列に接続されている複数の単電池１ａ及び１ｂを含む全固体リチウム二次電池１の充電状態バラツキを減少させる又は解消することができる。 On the other hand, as in the secondary battery system of the present disclosure, the discharge control is positively performed on the all solid lithium secondary battery 1 (for example, the normal discharge voltage lower limit value of the all solid lithium secondary battery 1) Discharge to a significantly lower voltage), a phenomenon occurs in which the discharge current starts to flow through the single cell 1b. The phenomenon in which the discharge current further flows from the stage where the unit cell 1b in which the state of charge is low is discharged to 0% SOC (the state where the reversible reaction inside the battery which can be normally used is completed) is considered to be due to the irreversible reaction in the unit cell 1b. It is done. In view of this, the present disclosure describes the whole of the plurality of unit cells 1a, 1b,..., 1x, and 1y so that the voltage of the unit cell 1b is equal to or lower than the irreversible reaction start voltage and larger than the irreversible reaction end voltage. By discharging (that is, the all-solid-state lithium secondary battery 1), it is possible to reduce the amount of 10% remaining charged state of the unit cell 1a having a relatively large charged state. That is, the variation in the state of charge of the all-solid lithium secondary battery 1 including the plurality of single cells 1a and 1b connected in series can be reduced or eliminated.
上記のように、複数の単電池の全体に対して積極的に放電制御を行うことによって、相対的に充電状態が低い方の単電池において、先に不可逆反応が起こる。この不可逆反応に関して、図３を用いて説明する。 As described above, by actively performing discharge control on the whole of the plurality of unit cells, the irreversible reaction first occurs in the unit cell having a relatively low charge state. This irreversible reaction will be described with reference to FIG.
図３は、事前に取得した単電池のサイクリックボルタンメトリー（ＣＶ）を示すイメージ図である。図３に示されているように、このサイクリックボルタンメトリーは、通常の電池の使用の際に用いる通常使用電圧領域と、通常の電池の使用の際に用いない非通常使用電圧領域とを分けることができる。この通常使用電圧領域の上限電圧におけるＳＯＣを１００％とし、下限電圧におけるＳＯＣを０％とすることができる。図３に示されているように、放電電圧下限値よりよりも小さい電圧まで放電させると、すなわち、ＳＯＣ０％を超えるまで放電させると、非通常使用電圧領域において、電流値が変動する「不可逆反応領域」（不可逆反応の開始電圧Ｖ１から不可逆反応の終了電圧Ｖ２までの間の領域）において放電が生じる。 FIG. 3 is an image diagram showing cyclic voltammetry (CV) of a single cell acquired in advance. As shown in FIG. 3, this cyclic voltammetry separates a normal use voltage range that is used when a normal battery is used from a non-normal use voltage range that is not used when a normal battery is used. Can do. The SOC at the upper limit voltage in the normal use voltage region can be set to 100%, and the SOC at the lower limit voltage can be set to 0%. As shown in FIG. 3, when discharging to a voltage lower than the lower limit of the discharge voltage, that is, discharging to a value exceeding SOC 0%, the current value fluctuates in the non-normally used voltage region. discharge occurs in the region "(the region between the start voltage V 1 of the irreversible reaction to the end voltage V 2 of the irreversible reaction).
また、この「不可逆反応」は、以下のメカニズムによるものであると推測される。すなわち、全固体二次電池では、活物質層と固体電解質層との界面に皮膜（ＳＥＩ：Ｓｏｌｉｄ Ｅｌｅｃｔｒｏｌｙｔｅ Ｉｎｔｅｒｐｈａｓｅ）が生じることがある。これに対して、積極的に放電制御を行うと、ＳＥＩの分解反応が起き、これによって、放電電流を消費することができる。したがって、充電状態が低い方の単電池が放電しきった段階（すなわち、絶縁部分となった段階）から、更に放電電流が流れる現象が起きる。 This “irreversible reaction” is presumed to be due to the following mechanism. That is, in an all-solid secondary battery, a film (SEI: Solid Electrolyte Interface) may be generated at the interface between the active material layer and the solid electrolyte layer. On the other hand, when the discharge control is positively performed, the decomposition reaction of SEI occurs, whereby the discharge current can be consumed. Therefore, a phenomenon occurs in which a discharge current further flows from the stage where the unit cell having the lower charged state is completely discharged (that is, the stage where the unit cell becomes an insulating portion).
すなわち、上記でいう「不可逆反応」は、このＳＥＩの分解反応であると推測される。また、このＳＥＩは、固体二次電池における任意の固体／固体界面で生じている可能性があるが、特に活物質と固体電解質材料との界面において多く生じていると考えられる。その理由は、活物質は、その表面で金属イオンの吸蔵放出というアクティブな反応を行い、固体電解質材料は、通常、活物質に接触する面積が大きいからである。中でも、活物質及び固体電解質材料が、互いに異なる種類の化合物に由来する組み合わせである場合に、ＳＥＩが生じやすい傾向にあると考えられる。一例を挙げると、酸化物活物質（酸化物に由来）と、硫化物固体電解質材料（硫化物に由来）とは、相対的に反応しやすく、ＳＥＩが生成しやすいと考えられる。なお、この「不可逆反応」については、特許文献２の記載を参照することもできる。 That is, the “irreversible reaction” mentioned above is presumed to be a decomposition reaction of this SEI. Further, this SEI may occur at an arbitrary solid / solid interface in the solid secondary battery, but it is considered that a large amount of SEI occurs particularly at the interface between the active material and the solid electrolyte material. The reason is that the active material undergoes an active reaction of occluding and releasing metal ions on the surface thereof, and the solid electrolyte material usually has a large area in contact with the active material. Especially, it is considered that SEI tends to occur when the active material and the solid electrolyte material are combinations derived from different types of compounds. For example, it is considered that an oxide active material (derived from an oxide) and a sulfide solid electrolyte material (derived from a sulfide) are relatively easily reacted with each other and SEI is likely to be generated. In addition, about this "irreversible reaction", the description of patent document 2 can also be referred.
なお、上述したメカニズムは、あくまで推測なものであり、本開示を何ら制限するものではない。 Note that the above-described mechanism is merely speculative, and does not limit the present disclosure.
以下では、図４に示されているフローチャートに沿って、本開示の二次電池システム及び二次電池制御方法の例を説明する。 Hereinafter, examples of the secondary battery system and the secondary battery control method according to the present disclosure will be described along the flowchart illustrated in FIG. 4.
図４に示されているように、本開示の二次電池システム又は二次電池制御方法をスタートした後で、電圧値取得部、電流値取得部、及び温度取得部から、複数の単電池の全体の電圧値Ｖ、電流値Ｉ、及び温度Ｔを取得する（Ｓ０１）。 As shown in FIG. 4, after starting the secondary battery system or the secondary battery control method of the present disclosure, the voltage value acquisition unit, the current value acquisition unit, and the temperature acquisition unit, The entire voltage value V, current value I, and temperature T are acquired (S01).
次に、演算部おいて、上記で取得した電圧値Ｖ、電流値Ｉ、及び温度Ｔから、複数の単電池の全体の実放電容量Ｑを算出する（Ｓ０２）。 Next, the calculation unit calculates the overall actual discharge capacity Q of the plurality of single cells from the voltage value V, the current value I, and the temperature T acquired above (S02).
そして、全体の実放電容量Ｑが所定の値よりも小さいと判断した場合（Ｓ０３）、すなわち、複数の単電池の間での充電状態にバラツキが生じていると判断した場合には、複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させる（Ｓ０４）。これによって、このバラツキを減少させる又は解消する。 When it is determined that the overall actual discharge capacity Q is smaller than a predetermined value (S03), that is, when it is determined that there is a variation in the charging state between the plurality of single cells, The whole of the plurality of single cells is discharged so that the voltage of at least one of the single cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage (S04). This reduces or eliminates this variation.
また、実放電容量Ｑが所定の値と同じ又は所定の値よりも大きいと判断した場合（Ｓ０３）、すなわち、複数の単電池の間での充電状態にバラツキが生じていないと判断した場合には、引き続き電圧値Ｖ、電流値Ｉ、及び温度Ｔ等を取得するステップ（Ｓ０１）に戻り、直列に接続されている複数の単電池を監視し続けることができる。 Further, when it is determined that the actual discharge capacity Q is equal to or greater than the predetermined value (S03), that is, when it is determined that there is no variation in the state of charge among the plurality of single cells. Can return to the step of acquiring the voltage value V, the current value I, the temperature T, etc. (S01), and can continue to monitor a plurality of cells connected in series.
ここで、実放電容量Ｑにかかる「所定の値」とは、特に限定されず、例えば使用による劣化等を考慮して推定の放電容量Ｑ０として設定することができる。また、実放電容量Ｑと推定の放電容量Ｑ０との関係を、ΔＱ（＝Ｑ０−Ｑ）で表すとき、「実放電容量（Ｑ）が所定の値よりも小さくなったとき」は、「ΔＱが所定の値より大きくなったとき」として判断することもできる。また、ΔＱにかかる「所定の値」は、特に限定されず、当業者によって適宜設定することができる。 Here, the “predetermined value” related to the actual discharge capacity Q is not particularly limited, and can be set as the estimated discharge capacity Q 0 in consideration of deterioration due to use, for example. Further, when the relationship between the actual discharge capacity Q and the estimated discharge capacity Q 0 is expressed by ΔQ (= Q 0 −Q), “when the actual discharge capacity (Q) becomes smaller than a predetermined value” It can also be determined as “when ΔQ becomes larger than a predetermined value”. Further, the “predetermined value” relating to ΔQ is not particularly limited, and can be appropriately set by those skilled in the art.
また、この放電ステップ（Ｓ０４）において、複数の単電池のうちの少なくとも一つののうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させるために、以下のような制御によって達成することができる。 In this discharging step (S04), the voltage of at least one of the plurality of unit cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. As described above, in order to discharge the entire plurality of single cells, the following control can be achieved.
すなわち、事前に任意の単電池のサイクリックボルタンメトリー（ＣＶ）を測定して、不可逆反応の開始電圧Ｖ１及び不可逆反応の終了電圧Ｖ２を取得することができる。これによって、当該単電池に係る不可逆反応の領域の電圧幅（｜Ｖ２−Ｖ１｜）を決めることができる。また、上述したように、複数の単電池のうちにおいて、放電処理前の充電状態が一番低い（少ない）単電池から先に不可逆反応が起きる。したがって、放電ステップ（Ｓ０４）にかかる放電は、例えば直列に接続されている複数の単電池の全体の電流値Ｉに対する監視によって、一旦電流が止まり、そして再び電流が消費される挙動の開始電圧は、放電処理前の充電状態が一番低い（少ない）単電池の不可逆反応の開始電圧と判断することができる。また、事前に取得した不可逆反応の領域の電圧幅によって、当該単電池の不可逆反応の終了電圧を決定することができる。この放電ステップ（Ｓ０４）では、この放電処理前の充電状態が一番低い（少ない）単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させることができる。なお、充電状態が一番低い（少ない）単電池が同程度の充電状態で二つ以上存在する場合、その個数を考慮して不可逆反応の開始電圧及び終了電圧を決めればよい。 That is, it is possible to pre-measure the cyclic voltammetry (CV) of any of the cells, to obtain the end voltage V 2 of the starting voltage V 1 and irreversible reactions irreversible reaction. Thereby, the voltage width (| V 2 −V 1 |) of the irreversible reaction region related to the unit cell can be determined. Further, as described above, the irreversible reaction occurs first from the unit cell having the lowest (smallest) charge state before the discharge treatment among the plurality of unit cells. Therefore, the discharge in the discharge step (S04) is performed by, for example, monitoring the overall current value I of a plurality of single cells connected in series, and the start voltage of the behavior in which the current is once stopped and the current is consumed again is It can be determined that this is the starting voltage of the irreversible reaction of the unit cell having the lowest (smallest) charge state before the discharge treatment. Moreover, the end voltage of the irreversible reaction of the cell can be determined by the voltage width of the irreversible reaction region acquired in advance. In this discharging step (S04), a plurality of voltage values are set so that the voltage of the unit cell having the lowest (smallest) state of charge before the discharging process is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. The whole single cell can be discharged. In addition, when two or more cells having the lowest (smallest) charge state exist in the same charge state, the start voltage and end voltage of the irreversible reaction may be determined in consideration of the number of cells.
放電ステップ（Ｓ０４）では、少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させた後、本開示の制御を終了（エンド）とさせることができる。 In the discharging step (S04), after discharging the whole of the plurality of unit cells so that the voltage of at least one unit cell is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage, The control of the disclosure can be ended (end).
また、本開示において、放電制御部は、複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ不可逆反応の終了電圧よりも大きい電圧になるように、複数の単電池の全体を放電させるため、複数の単電池の全体の通常放電電圧の下限値を、直列に接続されている複数の単電池の数に、２．７、２．５、２．０、１．５、１．０、又は０．５を乗じて得た通常放電総電圧の下限値（Ｖｌｉｍ）以下まで放電させることができる。また、放電制御部は、複数の単電池の全体の電池電圧を０Ｖまで放電するものであってもよく、電池が転極する（電池電圧が負になる）ように放電するものであってもよい。 Further, in the present disclosure, the discharge control unit includes a plurality of cells such that the voltage of at least one of the plurality of cells is equal to or lower than the irreversible reaction start voltage and greater than the irreversible reaction end voltage. In order to discharge the entire unit cell, the lower limit value of the normal discharge voltage of the entire unit cell is set to 2.7, 2.5, 2.0, the number of the plurality of unit cells connected in series. It is possible to discharge to a lower limit (V lim ) or less of the normal discharge total voltage obtained by multiplying 1.5, 1.0, or 0.5. Further, the discharge control unit may discharge the entire battery voltage of the plurality of single cells to 0 V, or may discharge so that the battery is reversed (battery voltage becomes negative). Good.
本開示にかかる放電制御部の一例としては、上記図２に示されているように、全固体リチウム二次電池１を外部短絡させる放電制御部６を挙げることができる。この場合の外部短絡のための回路は、抵抗９を有する回路であることが好ましい。 As an example of the discharge control unit according to the present disclosure, as shown in FIG. 2, a discharge control unit 6 that externally shorts the all-solid lithium secondary battery 1 can be cited. In this case, the circuit for external short circuit is preferably a circuit having a resistor 9.
このように、本開示の二次電池システム及び二次電池制御方法によって、直列に接続されている複数の単電池の間の充電状態のバラツキを減少させる又は解消することができる。 Thus, the secondary battery system and the secondary battery control method according to the present disclosure can reduce or eliminate variations in the charging state between the plurality of single cells connected in series.
〈追加制御〉
本開示の二次電池システム及び二次電池制御方法は、複数の単電池の全体の利用可能な電気量の低下が、複数の単電池の間での充電状態のバラツキによるものなのか、又は個々の単電池の劣化によるものなのかを判断する追加制御を更に含むことができる。
<Additional control>
In the secondary battery system and the secondary battery control method according to the present disclosure, the decrease in the total amount of electricity that can be used by the plurality of single cells is due to variation in the state of charge among the plurality of single cells, or individually. It may further include an additional control for determining whether the cell is due to deterioration of the single cell.
複数の単電池の全体の利用可能な電気量の低下が、複数の単電池の間の充電状態のバラツキによって生じている場合、本開示の二次電池システム及び二次電池制御方法によって、このバラツキを減少させる又は解消して、全体の充放電容量を回復させることができる。しかしながら、複数の単電池の全体の利用可能な電気量の低下が、個々の全固体リチウムイオン電池の劣化によって生じている場合、本開示の二次電池システム及び二次電池制御方法によっては全体の充放電容量を回復させることができず、むしろ過剰な放電を繰り返すことによって個々の単電池を更に劣化させる可能性がある。 In the case where the decrease in the total available electricity amount of the plurality of unit cells is caused by the variation in the charge state between the plurality of unit cells, this variation is achieved by the secondary battery system and the secondary battery control method of the present disclosure. Can be reduced or eliminated to restore the overall charge / discharge capacity. However, in the case where the decrease in the total available electricity amount of the plurality of single cells is caused by the deterioration of the individual all-solid-state lithium ion battery, depending on the secondary battery system and the secondary battery control method of the present disclosure, The charge / discharge capacity cannot be recovered, but rather, individual cells may be further deteriorated by repeating excessive discharge.
したがって、この追加制御を用いて、複数の単電池の全体の利用可能な電気量の低下が、複数の単電池の間の充電状態のバラツキによって生じているのか、又は個々の単電池の劣化によって生じているのかを判断することによって、本開示の二次電池システム及び二次電池制御方法を過剰に行い、それによってかえって単電池を更に劣化させてしまうことを抑制できる。 Therefore, by using this additional control, the decrease in the total available electricity amount of the plurality of single cells is caused by the variation in the charging state between the plurality of single cells, or due to deterioration of the individual single cells. By judging whether it has occurred, it is possible to suppress the secondary battery system and the secondary battery control method of the present disclosure from being excessively performed and thereby further degrading the single cell.
この追加制御の具体例を、図５を用いて説明する。すなわち、この追加制御１００では、本開示のシステム及び方法で充電容量を回復させる処理を行った後に、全体の電圧値Ｖ、電流値Ｉ、及び温度Ｔ等を取得し（Ｓ０５）、そして、実放電容量Ｑ’を算出する（Ｓ０６）。ここで、回復処理を行う前の実放電容量Ｑは、上述した算出ステップ（Ｓ０２）によって取得できる。次に、回復処理後の実放電容量Ｑ’と回復処理前の実放電容量Ｑとの差に基づき、ΔＱ’（＝Ｑ’−Ｑ）を算出し、この差ΔＱ’と、所定の値との関係を確認する（Ｓ０７）。ここで、この差ΔＱ’が所定の値より小さい場合、すなわち本開示のシステム及び方法によって複数の単電池の全体の容量が有意に回復しなかった場合には、個々の単電池の劣化によって、電池全体の容量が低下していたと判断することができる。この場合、個々の単電池の劣化発生を示すダイアグを表示できる（Ｓ０８）。一方、この差ΔＱ’が所定の値より大きいことは、本開示の二次電池システム及び二次電池制御方法による回復処理が達成できたことを意味する。なお、この差ΔＱ’にかかる「所定の値」は、特に限定されず、当業者によって適宜設定することができる。 A specific example of this additional control will be described with reference to FIG. That is, in this additional control 100, after performing the process of restoring the charging capacity by the system and method of the present disclosure, the entire voltage value V, current value I, temperature T, and the like are acquired (S05), and The discharge capacity Q ′ is calculated (S06). Here, the actual discharge capacity Q before performing the recovery process can be acquired by the calculation step (S02) described above. Next, ΔQ ′ (= Q′−Q) is calculated based on the difference between the actual discharge capacity Q ′ after the recovery process and the actual discharge capacity Q before the recovery process, and the difference ΔQ ′ is set to a predetermined value. (S07). Here, when the difference ΔQ ′ is smaller than a predetermined value, that is, when the overall capacity of the plurality of single cells is not significantly recovered by the system and method of the present disclosure, the deterioration of the individual single cells causes It can be determined that the capacity of the entire battery has been reduced. In this case, it is possible to display a diagnosis indicating the deterioration of each single cell (S08). On the other hand, the difference ΔQ ′ being larger than the predetermined value means that the recovery process by the secondary battery system and the secondary battery control method of the present disclosure has been achieved. The “predetermined value” relating to the difference ΔQ ′ is not particularly limited, and can be set as appropriate by those skilled in the art.
≪単電池の構成≫
本開示にかかる単電池は、全固体リチウム二次単電池である。このような単電池の構成は、特に限定されず、使用用途・目的に応じて設定すればよい。一例として、単電池は、正極集電体層、正極活物質層、固体電解質層、負極活物質層、及び負極集電体層をこの順で積層することによって、構成されうる。
≪Unit cell configuration≫
The cell according to the present disclosure is an all-solid lithium secondary cell. The configuration of such a unit cell is not particularly limited, and may be set according to the intended use / purpose. As an example, the unit cell can be configured by laminating a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer in this order.
また、本開示の効果をより顕著に表現する観点から、本開示の二次電池システム及び後述する二次電池制御方法において、直列に接続されている複数の単電池は、バイポーラ型の積層電池であることが好ましい。 In addition, from the viewpoint of more remarkably expressing the effects of the present disclosure, in the secondary battery system of the present disclosure and the secondary battery control method described later, the plurality of single cells connected in series are bipolar stacked batteries. Preferably there is.
〈集電体層〉
集電体層は、活物質層の、電解質層が積層される活物質層の面と反対側の面上に積層される。活物質層が正極活物質層である場合には、そこに積層される集電体層は、正極集電体層であり、活物質層が負極活物質層である場合には、そこに積層される集電体層は、負極集電体層である。また、全固体電池積層体がバイポーラ型である場合、正極／負極集電体層を用いることができる。ここで、「正極／負極集電体層」とは、いずれの電極（正極又は負極）としても役割を果たせるものを意味し、すなわち、バイポーラ型の全固体電池積層体の場合に、正極活物質層と負極活物質層とが共有できる集電体層を意味する。
<Current collector layer>
The current collector layer is laminated on the surface of the active material layer opposite to the surface of the active material layer on which the electrolyte layer is laminated. When the active material layer is a positive electrode active material layer, the current collector layer laminated thereon is a positive electrode current collector layer, and when the active material layer is a negative electrode active material layer, the current collector layer is laminated thereon. The current collector layer is a negative electrode current collector layer. Further, when the all-solid battery stack is of a bipolar type, a positive electrode / negative electrode current collector layer can be used. Here, the “positive electrode / negative electrode current collector layer” means what can play a role as any electrode (positive electrode or negative electrode), that is, in the case of a bipolar all-solid battery laminate, a positive electrode active material It means a current collector layer that can be shared by the layer and the negative electrode active material layer.
正極集電体層、負極集電体層、又は正極／負極集電体層を構成する材料の例としては、特に限定されず、各種金属、例えば、銀、銅、金、アルミニウム、ニッケル、鉄、ステンレス鋼（ＳＵＳ）、及びチタン等、並びにこれらの合金を挙げることができる。化学的安定性等の観点から、正極集電体層としては、アルミニウムの集電体層が好ましく、負極集電体層としては、銅の集電体層が好ましく、正極／負極集電体層としては、ＳＵＳが好ましい。 Examples of the material constituting the positive electrode current collector layer, the negative electrode current collector layer, or the positive electrode / negative electrode current collector layer are not particularly limited, and various metals such as silver, copper, gold, aluminum, nickel, and iron , Stainless steel (SUS), titanium, and the like, and alloys thereof. From the viewpoint of chemical stability and the like, the positive electrode current collector layer is preferably an aluminum current collector layer, and the negative electrode current collector layer is preferably a copper current collector layer, and the positive electrode / negative electrode current collector layer. As, SUS is preferable.
また、各集電体層の形状として、特に限定されず、例えば、箔状、板状、メッシュ状等を挙げることができる。 Moreover, it does not specifically limit as a shape of each collector layer, For example, foil shape, plate shape, mesh shape, etc. can be mentioned.
〈正極活物質層〉
正極活物質層は、少なくとも正極活物質を含み、好ましくは後述する固体電解質を更に含む。そのほか、使用用途や使用目的等に合わせて、例えば、導電助剤又はバインダー等の全固体電池の正極活物質層に用いられる添加剤を含むことができる。
<Positive electrode active material layer>
The positive electrode active material layer includes at least a positive electrode active material, and preferably further includes a solid electrolyte described later. In addition, an additive used for the positive electrode active material layer of an all-solid battery, such as a conductive additive or a binder, can be included in accordance with the intended use or intended purpose.
（正極活物質）
本開示において用いられる正極活物質の材料として、特に限定されず、公知のものが用いられる。例えば、正極活物質は、コバルト酸リチウム（ＬｉＣｏＯ２）、ニッケル酸リチウム（ＬｉＮｉＯ２）、マンガン酸リチウム（ＬｉＭｎ２Ｏ４）、ＬｉＣｏ１／３Ｎｉ１／３Ｍｎ１／３Ｏ２、Ｌｉ１＋ｘＭｎ２−ｘ−ｙＭｙＯ４（Ｍは、Ａｌ、Ｍｇ、Ｃｏ、Ｆｅ、Ｎｉ、及びＺｎから選ばれる１種以上の金属元素）で表される組成の異種元素置換Ｌｉ−Ｍｎスピネル、又は硫化物系（ＬｉｘＳ若しくはＬｉｘＭＳ２［Ｍ＝Ｆｅ、Ｔｉ等］）等であってよいが、これらに限定されない。
(Positive electrode active material)
The material of the positive electrode active material used in the present disclosure is not particularly limited, and known materials are used. For example, the positive electrode active material is lithium cobaltate (LiCoO 2 ), lithium nickelate (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), LiCo 1/3 Ni 1/3 Mn 1/3 O 2 , Li 1 + x Heterogeneous element-substituted Li—Mn spinel having a composition represented by Mn 2−x−y M y O 4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), Alternatively, it may be a sulfide system (LixS or LixMS 2 [M = Fe, Ti, etc.]), but is not limited thereto.
（導電助剤）
導電助剤としては、特に限定されず、公知のものが用いられる。例えば、導電助剤は、ＶＧＣＦ（気相成長法炭素繊維、Ｖａｐｏｒ Ｇｒｏｗｎ Ｃａｒｂｏｎ Ｆｉｂｅｒ）及びカーボンナノ繊維等の炭素材並びに金属材等であってよいが、これらに限定されない。
(Conductive aid)
The conductive auxiliary agent is not particularly limited, and known ones are used. For example, the conductive additive may be a carbon material such as VGCF (vapor grown carbon fiber) and carbon nanofiber, and a metal material, but is not limited thereto.
（バインダー）
バインダーとしては、特に限定されず、公知のものが用いられる。例えば、バインダーは、ポリフッ化ビニリデン（ＰＶｄＦ）、カルボキシメチルセルロース（ＣＭＣ）、ブタジエンゴム（ＢＲ）若しくはスチレンブタジエンゴム（ＳＢＲ）等の材料、又はこれらの組合せであってよいが、これらに限定されない。
(binder)
It does not specifically limit as a binder, A well-known thing is used. For example, the binder may be a material such as, but not limited to, polyvinylidene fluoride (PVdF), carboxymethyl cellulose (CMC), butadiene rubber (BR) or styrene butadiene rubber (SBR).
〈固体電解質層〉
固体電解質層は、少なくとも固体電解質を含む。固体電解質として、特に限定されず、全固体電池の固体電解質として利用可能な材料を用いることができる。例えば、固体電解質は、硫化物固体電解質、酸化物固体電解質、又はポリマー電解質等であってよいが、これらに限定されない。
<Solid electrolyte layer>
The solid electrolyte layer includes at least a solid electrolyte. The solid electrolyte is not particularly limited, and a material that can be used as a solid electrolyte of an all-solid battery can be used. For example, the solid electrolyte may be a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte, but is not limited thereto.
（硫化物固体電解質）
硫化物固体電解質の例として、例えば、Ｌｉ２Ｓ−ＳｉＳ２、ＬｉＩ−Ｌｉ２Ｓ−ＳｉＳ２、ＬｉＩ−Ｌｉ２Ｓ−Ｐ２Ｓ５、ＬｉＩ−ＬｉＢｒ−Ｌｉ２Ｓ−Ｐ２Ｓ５、Ｌｉ２Ｓ−Ｐ２Ｓ５−ＬｉＩ−ＬｉＢｒ、Ｌｉ２Ｓ−Ｐ２Ｓ５−ＧｅＳ２、ＬｉＩ−Ｌｉ２Ｓ−Ｐ２Ｏ５、ＬｉＩ−Ｌｉ３ＰＯ４−Ｐ２Ｓ５、及びＬｉ２Ｓ−Ｐ２Ｓ５等；硫化物系結晶質固体電解質、例えば、Ｌｉ１０ＧｅＰ２Ｓ１２、Ｌｉ７Ｐ３Ｓ１１、Ｌｉ３ＰＳ４、及びＬｉ３．２５Ｐ０．７５Ｓ４等；並びにこれらの組み合わせを挙げることができる。
(Sulfide solid electrolyte)
Examples of the sulfide solid electrolyte include, for example, Li 2 S—SiS 2 , LiI—Li 2 S—SiS 2 , LiI—Li 2 S—P 2 S 5 , LiI—LiBr—Li 2 S—P 2 S 5 , Li 2 S-P 2 S 5 -LiI-LiBr, Li 2 S-P 2 S 5 -GeS 2, LiI-Li 2 S-P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5, and Li 2 S-P 2 S 5 and the like; sulfide-based crystalline solid electrolytes such as Li 10 GeP 2 S 12 , Li 7 P 3 S 11 , Li 3 PS 4 , and Li 3.25 P 0.75 S 4 As well as combinations thereof.
（酸化物固体電解質）
酸化物固体電解質の例として、Ｌｉ７Ｌａ３Ｚｒ２Ｏ１２、Ｌｉ７−ｘＬａ３Ｚｒ１−ｘＮｂｘＯ１２、Ｌｉ７−３ｘＬａ３Ｚｒ２ＡｌｘＯ１２、Ｌｉ３ｘＬａ２／３−ｘＴｉＯ３、Ｌｉ１＋ｘＡｌｘＴｉ２−ｘ（ＰＯ４）３、Ｌｉ１＋ｘＡｌｘＧｅ２−ｘ（ＰＯ４）３、Ｌｉ３ＰＯ４、及びＬｉ３＋ｘＰＯ４−ｘＮｘ（ＬｉＰＯＮ）等が挙げられるが、これらに限定されない。
(Oxide solid electrolyte)
Examples of the oxide solid electrolyte, Li 7 La 3 Zr 2 O 12, Li 7-x La 3 Zr 1-x Nb x O 12, Li 7-3x La 3 Zr 2 Al x O 12, Li 3x La 2 / 3-x TiO 3 , Li 1 + x Al x Ti 2-x (PO 4 ) 3 , Li 1 + x Al x Ge 2-x (PO 4 ) 3 , Li 3 PO 4 , and Li 3 + x PO 4-x N x (LiPON ) And the like, but is not limited thereto.
（ポリマー電解質）
ポリマー電解質としては、ポリエチレンオキシド（ＰＥＯ）、ポリプロピレンオキシド（ＰＰＯ）、及びこれらの共重合体等が挙げられるが、これらに限定されない。
(Polymer electrolyte)
Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.
固体電解質は、ガラスであっても、結晶化ガラス(ガラスセラミック)であってもよい。 The solid electrolyte may be glass or crystallized glass (glass ceramic).
また、固体電解質層は、上述した固体電解質以外に、必要に応じてバインダー等を含んでもよい。具体例として、上述の「正極活物質層」で列挙された「バインダー」と同様であり、ここでは説明を省略する。 Moreover, the solid electrolyte layer may contain a binder or the like as necessary in addition to the solid electrolyte described above. A specific example is the same as the “binder” listed in the “positive electrode active material layer” described above, and a description thereof is omitted here.
〈負極活物質層〉
負極活物質層は、少なくとも負極活物質を含み、好ましくは上述した固体電解質を更に含む。そのほか、使用用途や使用目的等に合わせて、導電助剤又はバインダー等の全固体電池の負極活物質層に用いられる添加剤を含むことができる。
<Negative electrode active material layer>
The negative electrode active material layer includes at least a negative electrode active material, and preferably further includes the solid electrolyte described above. In addition, an additive used for the negative electrode active material layer of the all-solid battery, such as a conductive additive or a binder, can be included in accordance with the intended use or intended purpose.
（負極活物質）
本開示において用いられる負極活物質の材料として、特に限定されず、リチウムイオン等の金属イオンを吸蔵及び放出可能であることが好ましい。例えば、Ｌｉ、Ｓｎ、Ｓｉ若しくはＩｎなどの金属、リチウムとチタンとの合金、又はハードカーボン、ソフトカーボン若しくはグラファイトなどの炭素材料などが挙げられるが、これらに限定されない。
(Negative electrode active material)
The material of the negative electrode active material used in the present disclosure is not particularly limited, and it is preferable that metal ions such as lithium ions can be occluded and released. Examples include, but are not limited to, metals such as Li, Sn, Si, or In, alloys of lithium and titanium, or carbon materials such as hard carbon, soft carbon, or graphite.
（添加剤）
負極活物質層に用いられる固体電解質、導電助剤、バインダーなどその他の添加剤については、正極活物質層及び固体電解質層に関して説明したものを適宜採用することができる。
(Additive)
About other additives, such as a solid electrolyte used for a negative electrode active material layer, a conductive support agent, and a binder, what was demonstrated regarding the positive electrode active material layer and the solid electrolyte layer is employable suitably.
１ 全固体リチウム二次電池
１ａ、１ｂ、１ｘ、１ｙ 単電池
２ 電圧値取得部
３ 電流値取得部
４ 温度取得部
５ 演算部
６ 放電制御部
７、８ スイッチ
９ 抵抗
１０ 二次電池システム
１００ 追加制御
DESCRIPTION OF SYMBOLS 1 All-solid-state lithium secondary battery 1a, 1b, 1x, 1y cell 2 Voltage value acquisition part 3 Current value acquisition part 4 Temperature acquisition part 5 Calculation part 6 Discharge control part 7, 8 Switch 9 Resistance 10 Secondary battery system 100 addition control
Claims (1)
前記複数の単電池の全体の電圧値、電流値、及び温度をそれぞれ取得する電圧値取得部、電流値取得部、及び温度取得部、
前記電圧値、前記電流値、及び前記温度から、前記複数の単電池の全体の実放電容量を算出する演算部、並びに
前記全体の実放電容量が所定の値よりも小さくなったときに、前記複数の単電池のうちの少なくとも一つの単電池の電圧が不可逆反応の開始電圧以下、かつ前記不可逆反応の終了電圧よりも大きい電圧になるように、前記複数の単電池の全体を放電させる、放電制御部を有し、かつ
前記単電池が、全固体リチウム二次単電池である、
二次電池システム。 Multiple cells connected in series,
A voltage value acquisition unit, a current value acquisition unit, and a temperature acquisition unit that respectively acquire the overall voltage value, current value, and temperature of the plurality of single cells,
From the voltage value, the current value, and the temperature, a calculation unit that calculates an overall actual discharge capacity of the plurality of single cells, and when the overall actual discharge capacity becomes smaller than a predetermined value, Discharging the whole of the plurality of unit cells so that the voltage of at least one unit cell of the plurality of unit cells is equal to or lower than the irreversible reaction start voltage and higher than the irreversible reaction end voltage. A control unit, and the unit cell is an all-solid lithium secondary unit cell,
Secondary battery system.
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| JP2017195169A (en) * | 2015-06-16 | 2017-10-26 | 株式会社リコー | Storage apparatus, control apparatus, and moving body |
| JP2017037734A (en) * | 2015-08-07 | 2017-02-16 | トヨタ自動車株式会社 | Secondary battery system |
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