JP7047548B2 - Rechargeable battery system - Google Patents

Rechargeable battery system Download PDF

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JP7047548B2
JP7047548B2 JP2018070931A JP2018070931A JP7047548B2 JP 7047548 B2 JP7047548 B2 JP 7047548B2 JP 2018070931 A JP2018070931 A JP 2018070931A JP 2018070931 A JP2018070931 A JP 2018070931A JP 7047548 B2 JP7047548 B2 JP 7047548B2
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current collector
component value
collector foil
electrode current
impedance
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JP2019185861A (en
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淳史 宝来
英明 堀江
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Nissan Motor Co Ltd
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    • 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

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  • Cell Electrode Carriers And Collectors (AREA)

Description

本発明は、電解液の漏洩が検知できる二次電池システムに関する。 The present invention relates to a secondary battery system capable of detecting leakage of an electrolytic solution.

近年、環境問題およびエネルギー問題の解決に向けて、種々の電気自動車の普及が期待されている。しかし、これらの電気自動車を普及させるためには、少なくとも一充電当たりの走行距離をガソリンエンジン車に近づける必要がある。このため、より高いエネルギー密度を有する二次電池の開発が鋭意行われている。 In recent years, various electric vehicles are expected to become widespread in order to solve environmental problems and energy problems. However, in order to popularize these electric vehicles, it is necessary to bring at least the mileage per charge closer to that of a gasoline engine vehicle. Therefore, the development of a secondary battery having a higher energy density is being enthusiastically carried out.

たとえば、高いエネルギー密度を有する二次電池を実現させる技術としては、特許文献１に開示されているものがある。特許文献１では、正極集電体と負極集電体との間を封着部材によって封着させ、これによって単セル間の短絡が防止できるようにしている。この技術によれば、液状の電解液が使用できるようになるので、通常の二次電池と遜色ない出力密度が得られ、また、電池ケースが省略できるので、その分エネルギー密度を向上させることができる。 For example, as a technique for realizing a secondary battery having a high energy density, there is one disclosed in Patent Document 1. In Patent Document 1, the positive electrode current collector and the negative electrode current collector are sealed by a sealing member, whereby a short circuit between single cells can be prevented. According to this technology, since a liquid electrolytic solution can be used, an output density comparable to that of a normal secondary battery can be obtained, and since a battery case can be omitted, the energy density can be improved accordingly. can.

特開２００４－３４９１５６号公報Japanese Unexamined Patent Publication No. 2004-349156

従来の二次電池のエネルギー密度をさらに向上させるには、電気エネルギーを外部に取り出すための、正極集電板および負極集電板の厚みをさらに薄くする等、二次電池の主材料以外の構成部材の容量比率を下げる必要がある。しかし、正極集電板および負極集電板の厚みを薄くすれば、二次電池を構成する単セルの外装体強度が弱くなる。 In order to further improve the energy density of the conventional secondary battery, the thickness of the positive electrode current collector plate and the negative electrode current collector plate for extracting electric energy to the outside is further reduced, and the configuration other than the main material of the secondary battery is configured. It is necessary to reduce the capacity ratio of the members. However, if the thickness of the positive electrode current collector plate and the negative electrode current collector plate is reduced, the strength of the exterior body of the single cell constituting the secondary battery is weakened.

特に、単セルを構成する正極集電体および負極集電体を樹脂で形成した、投影面積の大きな（数十センチ×数十センチ以上）二次電池の場合、二次電池にかかる応力によって、正極集電体および負極集電体に亀裂が入り、その亀裂から電解液が染み出てきたり、漏れたりする恐れがある。 In particular, in the case of a secondary battery having a large projected area (several tens of centimeters x several tens of centimeters or more) in which the positive electrode current collector and the negative electrode current collector constituting the single cell are formed of resin, the stress applied to the secondary battery causes the secondary battery. The positive electrode current collector and the negative electrode current collector may be cracked, and the electrolytic solution may seep out or leak from the cracks.

電解液が漏洩すると、二次電池の容量が低下してしまったり、満充電時の容量が低下してしまったりするため、二次電池の性能低下が問題となる。また、特に、漏れた電解液が単セルの外側から染み出すと、単セル間の短絡の原因となるため、二次電池の安全性および信頼性も問題となる。このため、電解液の漏洩は迅速に検知する必要がある。 If the electrolytic solution leaks, the capacity of the secondary battery may decrease or the capacity when fully charged may decrease, so that the performance of the secondary battery deteriorates. Further, in particular, if the leaked electrolyte seeps out from the outside of the single cell, it causes a short circuit between the single cells, so that the safety and reliability of the secondary battery also become a problem. Therefore, it is necessary to quickly detect the leakage of the electrolytic solution.

そこで、本発明は、電解液の漏洩が検知できる二次電池システムの提供を目的とする。 Therefore, an object of the present invention is to provide a secondary battery system capable of detecting leakage of an electrolytic solution.

上記目的を達成するための本発明に係る二次電池システムは、二次電池、インピーダンス計測部、および電解液漏洩判断部を有する。二次電池は、正極集電箔と負極集電箔とが積層された集電体の、正極側に正極活物質層、負極側に負極活物質層が形成された双極電極を、電解液が含まれるセパレータを介して直列に複数接続した積層体を有し、前記正極集電箔、前記正極活物質層、前記セパレータ、前記負極活物質層および前記負極集電箔によって発電要素が形成され、前記発電要素の端部に、前記正極活物質層、前記負極活物質層およびセパレータの周囲を封止するシール部が設けられてなる。インピーダンス計測部は、隣り合う２つの発電要素の隣接する正極集電箔と負極集電箔との間のインピーダンスを計測する。電解液漏洩判断部は、計測された前記インピーダンスを用いて、前記セパレータに含まれる電解液が、前記正極活物質層および前記正極集電箔、または前記負極活物質層および前記負極集電箔から、隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間に漏洩したことを判断する。 The secondary battery system according to the present invention for achieving the above object includes a secondary battery , an impedance measurement unit, and an electrolytic solution leakage determination unit. The secondary battery is a bipolar electrode in which a positive electrode collector foil and a negative electrode current collector foil are laminated, and a positive electrode active material layer is formed on the positive electrode side and a negative electrode active material layer is formed on the negative electrode side. It has a laminate in which a plurality of layers are connected in series via a contained separator, and a power generation element is formed by the positive electrode current collector foil, the positive electrode active material layer, the separator, the negative electrode active material layer, and the negative electrode current collector foil. At the end of the power generation element, a sealing portion for sealing the periphery of the positive electrode active material layer, the negative electrode active material layer, and the separator is provided. The impedance measuring unit measures the impedance between the adjacent positive electrode current collector foil and the negative electrode current collector foil of two adjacent power generation elements . The electrolytic solution leakage determination unit uses the measured impedance to allow the electrolytic solution contained in the separator to flow from the positive electrode active material layer and the positive electrode current collector foil, or the negative electrode active material layer and the negative electrode current collector foil. , It is determined that leakage has occurred between the positive electrode current collector foil and the negative electrode current collector foil adjacent to each other of the two adjacent power generation elements .

本発明に係る二次電池システムによれば、双極電極の正極集電箔と負極集電箔との間の電解液の漏洩が検知できる。このため、漏洩した電解液を原因とする、二次電池の電池性能の低下が防止でき、二次電池の信頼性と安全性とが確保できる。 According to the secondary battery system according to the present invention, leakage of the electrolytic solution between the positive electrode current collector foil and the negative electrode current collector foil of the bipolar electrode can be detected. Therefore, deterioration of the battery performance of the secondary battery due to the leaked electrolytic solution can be prevented, and the reliability and safety of the secondary battery can be ensured.

本実施形態に係る二次電池の断面図である。It is sectional drawing of the secondary battery which concerns on this embodiment. 本実施形態に係る二次電池システムの概略構成図である。It is a schematic block diagram of the secondary battery system which concerns on this embodiment. 図２のインピーダンス計測部のブロック図である。It is a block diagram of the impedance measurement part of FIG. 図２の電解液漏洩判断部のブロック図である。It is a block diagram of the electrolytic solution leakage determination part of FIG. 電解液が漏洩していない場合の集電体の状態を示す図である。It is a figure which shows the state of the current collector when the electrolytic solution does not leak. 電解液が漏洩していない場合の等価回路図である。It is an equivalent circuit diagram when the electrolytic solution does not leak. 電解液が漏洩している場合の集電体の状態を示す図である。It is a figure which shows the state of the current collector when the electrolytic solution leaks. 電解液が漏洩している場合の等価回路図である。It is an equivalent circuit diagram in the case where the electrolytic solution is leaking. 本実施形態に係る二次電池システムの動作フローチャートである。It is an operation flowchart of the secondary battery system which concerns on this embodiment. 図６のＳ１００のステップのサブルーチンフローチャートである。It is a subroutine flowchart of the step of S100 of FIG. 電解液が漏洩していない場合のコールコールプロット図である。It is a call call plot figure in the case where the electrolytic solution does not leak. 電解液が漏洩している場合のコールコールプロット図である。It is a call call plot figure in the case where an electrolytic solution is leaking. 図６のＳ１１０のステップのサブルーチンフローチャートである。It is a subroutine flowchart of the step of S110 of FIG.

以下、図面を参照しながら本発明の実施形態について説明する。なお、図面の寸法比率は、説明の都合上誇張されており、実際の寸法比率とは異なる場合がある。また、本発明の技術的範囲は特許請求の範囲の記載に基づいて定められ、以下の実施形態の記載に限定されるものでない。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual dimensional ratios. Further, the technical scope of the present invention is defined based on the description of the scope of claims, and is not limited to the description of the following embodiments.

［二次電池１０の構成］
本実施形態に係る二次電池１０の一例として双極型リチウムイオン二次電池について説明する。なお、以下の説明では、双極型リチウムイオン二次電池を単に「二次電池」と称する。 [Structure of secondary battery 10]
A bipolar lithium-ion secondary battery will be described as an example of the secondary battery 10 according to the present embodiment. In the following description, the bipolar lithium ion secondary battery is simply referred to as a "secondary battery".

図１は、本実施形態に係る二次電池１０の断面図である。図１に示すように、二次電池１０は、複数の発電要素２０を積層してなる積層体１１が外装体１２の内部で封止された構造を有する。積層体１１は、外装体１２によって、外部から受ける応力や外部から受ける環境の影響から保護される。なお、発電要素２０の積層数は、所望する電圧に応じて変える。 FIG. 1 is a cross-sectional view of the secondary battery 10 according to the present embodiment. As shown in FIG. 1, the secondary battery 10 has a structure in which a laminated body 11 formed by laminating a plurality of power generation elements 20 is sealed inside an exterior body 12. The laminate 11 is protected from external stress and external environmental influences by the exterior body 12. The number of stacked power generation elements 20 is changed according to the desired voltage.

図１に示すように、二次電池１０は、積層体１１の最上部に位置する発電要素２０の正極集電箔３１ａ上に、正極集電箔３１ａと接触する正極集電板３４ａが配置される。正極集電板３４ａは外装体１２に向けて延長され外装体１２から外部に導出される。また、積層体１１の最下部に位置する発電要素２０の負極集電箔３１ｂ下に、負極集電箔３１ｂと接触する負極集電板３４ｂが配置される。負極集電板３４ｂは外装体１２に向けて延長され外装体１２から外部に導出される。 As shown in FIG. 1, in the secondary battery 10, a positive electrode current collector plate 34a in contact with the positive electrode current collector foil 31a is arranged on the positive electrode current collector foil 31a of the power generation element 20 located at the uppermost portion of the laminated body 11. To. The positive electrode current collector plate 34a is extended toward the exterior body 12 and is led out from the exterior body 12. Further, a negative electrode current collector plate 34b in contact with the negative electrode current collector foil 31b is arranged under the negative electrode current collector foil 31b of the power generation element 20 located at the lowermost portion of the laminated body 11. The negative electrode current collector plate 34b is extended toward the exterior body 12 and is led out from the exterior body 12.

発電要素２０は、負極集電箔３１ｂと、負極集電箔３１ｂ上に形成された負極活物質層３２ｂと、正極集電箔３１ａと、正極集電箔３１ａ上に形成された正極活物質層３２ａと、負極活物質層３２ｂおよび正極活物質層３２ａの間に介在する、電解液が含まれるセパレータ４０とから構成される。発電要素２０の両端部にはシール部５０が設けられている。シール部５０は、正極活物質層３２ａ、負極活物質層３２ｂおよびセパレータ４０の周囲を液密に封止し、電解液の漏れによる液絡を防止している。 The power generation element 20 includes a negative electrode current collector foil 31b, a negative electrode active material layer 32b formed on the negative electrode current collector foil 31b, a positive electrode current collector foil 31a, and a positive electrode active material layer formed on the positive electrode current collector foil 31a. It is composed of 32a and a separator 40 containing an electrolytic solution, which is interposed between the negative electrode active material layer 32b and the positive electrode active material layer 32a. Seals 50 are provided at both ends of the power generation element 20. The sealing portion 50 tightly seals the periphery of the positive electrode active material layer 32a, the negative electrode active material layer 32b, and the separator 40 to prevent liquid leakage due to leakage of the electrolytic solution.

積層体１１は発電要素２０を複数積層したものである。換言すれば、積層体１１は、正極集電箔３１ａと負極集電箔３１ｂとが積層された集電体３１の、正極側に正極活物質層３２ａ、負極側に負極活物質層３２ｂが形成された双極電極３５を、電解液が含まれるセパレータ４０を介して直列に接続したものであるとも言える。 The laminated body 11 is a stack of a plurality of power generation elements 20. In other words, in the laminated body 11, the positive electrode active material layer 32a is formed on the positive electrode side and the negative electrode active material layer 32b is formed on the negative electrode side of the current collector 31 in which the positive electrode collecting foil 31a and the negative electrode collecting foil 31b are laminated. It can also be said that the bipolar electrodes 35 are connected in series via a separator 40 containing an electrolytic solution.

（集電体）
集電体３１（正極集電箔３１ａおよび負極集電箔３１ｂ）は、正極活物質層３２ａと接する一方の面から、負極活物質層３２ｂと接する他方の面へと電子の移動を媒介する機能を有する。正極集電箔３１ａおよび負極集電箔３１ｂを構成する材料は、特に限定されないが、例えば、導電性を有する樹脂、樹脂を含む導電材料、または金属が用いられうる。 (Current collector)
The current collector 31 (positive electrode current collector foil 31a and negative electrode current collector foil 31b) has a function of mediating the movement of electrons from one surface in contact with the positive electrode active material layer 32a to the other surface in contact with the negative electrode active material layer 32b. Has. The material constituting the positive electrode current collector foil 31a and the negative electrode current collector foil 31b is not particularly limited, and for example, a conductive resin, a conductive material containing a resin, or a metal can be used.

集電体３１の軽量化の観点からは、集電体３１を構成する正極集電箔３１ａおよび負極集電箔３１ｂは、上記のように、樹脂または樹脂を含む導電材料で形成された樹脂集電体であることが好ましい。なお、発電要素２０間のリチウムイオンの移動を遮断する観点からは、樹脂集電体の一部に金属層を設けてもよい。 From the viewpoint of reducing the weight of the current collector 31, the positive electrode current collector foil 31a and the negative electrode current collector foil 31b constituting the current collector 31 are resin collections formed of resin or a conductive material containing resin as described above. It is preferably an electric body. From the viewpoint of blocking the movement of lithium ions between the power generation elements 20, a metal layer may be provided on a part of the resin current collector.

（正極活物質層、負極活物質層）
電極活物質層３２（正極活物質層３２ａ、負極活物質層３２ｂ）は、電極活物質（正極活物質または負極活物質）および電解液を含む。また、電極活物質層３２は、必要に応じて、導電助剤、導電部材、被覆用樹脂等を含んでもよい。さらに、電極活物質層３２は、必要に応じてイオン伝導性ポリマー、リチウム塩等を含んでもよい。 (Positive electrode active material layer, Negative electrode active material layer)
The electrode active material layer 32 (positive electrode active material layer 32a, negative electrode active material layer 32b) contains an electrode active material (positive electrode active material or negative electrode active material) and an electrolytic solution. Further, the electrode active material layer 32 may contain a conductive auxiliary agent, a conductive member, a coating resin and the like, if necessary. Further, the electrode active material layer 32 may contain an ion conductive polymer, a lithium salt, or the like, if necessary.

（正極活物質）
正極活物質としては、例えば、ＬｉＭｎ２Ｏ４、ＬｉＣｏＯ２、ＬｉＮｉＯ２、Ｌｉ（Ｎｉ－Ｍｎ－Ｃｏ）Ｏ２およびこれらの遷移金属の一部が他の元素により置換されたもの等のリチウム－遷移金属複合酸化物、リチウム－遷移金属リン酸化合物、リチウム－遷移金属硫酸化合物等が挙げられる。 (Positive electrode active material)
Examples of the positive electrode active material include LiMn 2 O 4 , LiCoO 2 , LiNiO 2 , Li (Ni—Mn—Co) O 2 , and lithium such as those in which some of these transition metals are replaced by other elements. Examples thereof include transition metal composite oxides, lithium-transition metal phosphate compounds, and lithium-transition metal sulfate compounds.

（負極活物質）
負極活物質としては、例えば、グラファイト（黒鉛）、ソフトカーボン、ハードカーボン等の炭素材料、リチウム－遷移金属複合酸化物（例えば、Ｌｉ４Ｔｉ５Ｏ１２）、金属材料（スズ、シリコン）、リチウム合金系負極材料（例えばリチウム－スズ合金、リチウム－シリコン合金、リチウム－アルミニウム合金、リチウム－アルミニウム－マンガン合金等）等が挙げられる。 (Negative electrode active material)
Examples of the negative electrode active material include carbon materials such as graphite (graphite), soft carbon, and hard carbon, lithium-transition metal composite oxides (for example, Li 4 Ti 5 O 12 ), metal materials (tin, silicon), and lithium. Examples thereof include alloy-based negative electrode materials (for example, lithium-tin alloy, lithium-silicon alloy, lithium-aluminum alloy, lithium-aluminum-manganese alloy, etc.).

（導電助剤）
導電助剤は、電極活物質層３２中で電子伝導パスを形成し、電極活物質層３２の電子移動抵抗を低減することで、二次電池１０の高レートでの出力特性向上に寄与し得る。 (Conductive aid)
The conductive auxiliary agent can contribute to the improvement of the output characteristics of the secondary battery 10 at a high rate by forming an electron conduction path in the electrode active material layer 32 and reducing the electron transfer resistance of the electrode active material layer 32. ..

（導電部材）
導電部材は、電極活物質層３２中で電子伝導パスを形成する機能を有する。特に、導電部材の少なくとも一部が、電極活物質層３２の２つの主面同士を電気的に接続する導電通路を形成していることが好ましい。このような形態を有することで、電極活物質層３２中の厚さ方向の電子移動抵抗がさらに低減されるため、二次電池１０の高レートでの出力特性をより一層向上しうる。 (Conductive member)
The conductive member has a function of forming an electron conduction path in the electrode active material layer 32. In particular, it is preferable that at least a part of the conductive member forms a conductive passage that electrically connects the two main surfaces of the electrode active material layer 32. By having such a form, the electron transfer resistance in the thickness direction in the electrode active material layer 32 is further reduced, so that the output characteristics of the secondary battery 10 at a high rate can be further improved.

本実施形態の二次電池１０において、電極活物質層３２の厚さは、正極活物質層３２ａについては、好ましくは１５０～１５００μｍであり、より好ましくは１８０～９５０μｍであり、さらに好ましくは２００～８００μｍである。また、負極活物質層３２ｂの厚さは、好ましくは１５０～１５００μｍであり、より好ましくは１８０～１２００μｍであり、さらに好ましくは２００～１０００μｍである。電極活物質層３２の厚さが上記した下限値以上の値であれば、二次電池１０のエネルギー密度を十分に高めることができる。一方、電極活物質層３２の厚さが上記した上限値以下の値であれば、電極活物質層３２の構造を十分に維持することができる。 In the secondary battery 10 of the present embodiment, the thickness of the electrode active material layer 32 is preferably 150 to 1500 μm, more preferably 180 to 950 μm, still more preferably 200 to 200 to 500 μm for the positive electrode active material layer 32a. It is 800 μm. The thickness of the negative electrode active material layer 32b is preferably 150 to 1500 μm, more preferably 180 to 1200 μm, and further preferably 200 to 1000 μm. When the thickness of the electrode active material layer 32 is at least the above-mentioned lower limit value, the energy density of the secondary battery 10 can be sufficiently increased. On the other hand, if the thickness of the electrode active material layer 32 is not more than the above-mentioned upper limit value, the structure of the electrode active material layer 32 can be sufficiently maintained.

（セパレータ）
セパレータ４０は、電解質を保持し、正極活物質層３２ａと負極活物質層３２ｂとの間にあって両者が直接に接触することを防止する。本実施形態のセパレータ４０に使用される電解質は、特に制限はなく、例えば、電解液またはゲルポリマー電解質等が挙げられる。これらの電解質を用いることで、高いリチウムイオン伝導性が確保されうる。なお、電解液は、上記の電極活物質層３２に使用される電解液と同様のものが用いられうる。 (Separator)
The separator 40 retains the electrolyte and is between the positive electrode active material layer 32a and the negative electrode active material layer 32b to prevent them from coming into direct contact with each other. The electrolyte used in the separator 40 of the present embodiment is not particularly limited, and examples thereof include an electrolytic solution and a gel polymer electrolyte. By using these electrolytes, high lithium ion conductivity can be ensured. As the electrolytic solution, the same electrolytic solution as that used for the electrode active material layer 32 may be used.

（正極集電板および負極集電板）
集電板３４（正極集電板３４ａと負極集電板３４ｂの総称）を構成する材料は、特に制限されず、二次電池用の集電板３４として従来用いられている公知の高導電性材料が用いられうる。集電板３４の構成材料としては、例えば、アルミニウム、銅、チタン、ニッケル、ステンレス、これらの合金等の金属材料が好ましい。軽量、耐食性、高導電性の観点から、より好ましくはアルミニウム、銅であり、特に好ましくはアルミニウムである。なお、正極集電板３４ａと負極集電板３４ｂとでは、同一の材料が用いられてもよいし、異なる材料が用いられてもよい。 (Positive current collector plate and negative electrode current collector plate)
The material constituting the current collector plate 34 (general term for the positive electrode current collector plate 34a and the negative electrode current collector plate 34b) is not particularly limited, and is known to have high conductivity conventionally used as a current collector plate 34 for a secondary battery. Materials can be used. As the constituent material of the current collector plate 34, for example, metal materials such as aluminum, copper, titanium, nickel, stainless steel, and alloys thereof are preferable. From the viewpoint of light weight, corrosion resistance, and high conductivity, aluminum and copper are more preferable, and aluminum is particularly preferable. The same material may be used for the positive electrode current collector plate 34a and the negative electrode current collector plate 34b, or different materials may be used.

（シール部）
シール部５０は、発電要素２０を構成する集電体３１同士の接触や発電要素２０の端部における短絡を防止する機能を有する。シール部５０を構成する材料としては、絶縁性、シール性（液密性）、電池動作温度下での耐熱性等を有するものであればよい。 (Seal part)
The seal portion 50 has a function of preventing contact between the current collectors 31 constituting the power generation element 20 and a short circuit at the end of the power generation element 20. The material constituting the seal portion 50 may be any material having insulating property, sealing property (liquidtightness), heat resistance under the battery operating temperature, and the like.

（外装体）
図１に示す本実施形態では、外装体１２は、ラミネートフィルムによって袋状に構成されているが、これに限定されず、例えば、公知の金属缶ケース等を用いてもよい。高出力化や冷却性能に優れ、ＥＶ、ＨＥＶ用の大型機器用の二次電池に好適に利用することができるという観点からは、外装体１２は、ラミネートフィルムによって構成することが好ましい。ラミネートフィルムには、例えば、ポリプロピレン（ＰＰ）、アルミニウム、ナイロンをこの順に積層してなる３層構造のラミネートフィルム等を用いることができるが、これらに限定されるものではない。また、外部から掛かる積層体１１への群圧を、容易に調整できることから、外装体１２はアルミネートラミネートフィルムを用いることがより好ましい。 (Exterior body)
In the present embodiment shown in FIG. 1, the exterior body 12 is formed in a bag shape by a laminated film, but the present invention is not limited to this, and for example, a known metal can case or the like may be used. The exterior body 12 is preferably made of a laminated film from the viewpoint that it has excellent high output and cooling performance and can be suitably used as a secondary battery for large-sized equipment for EVs and HEVs. As the laminating film, for example, a laminated film having a three-layer structure in which polypropylene (PP), aluminum, and nylon are laminated in this order can be used, but the laminating film is not limited thereto. Further, it is more preferable to use an aluminate laminated film for the exterior body 12 because the group pressure applied to the laminated body 11 from the outside can be easily adjusted.

［二次電池システムの構成］
図２は、本実施形態に係る二次電池システム１００の概略構成図である。二次電池システム１００は、積層体１１（図１参照）、インピーダンス計測部１２０、電解液漏洩判断部１４０、および警報部２００を有する。図２では、積層体１１の一部として、積層された２つの発電要素２０を示した。インピーダンス計測部１２０および電解液漏洩判断部１４０は、便宜上２つのブロックに分けて記載しているが、これらの部分は、通常ＲＡＭ、ＲＯＭ等の半導体メモリとＣＰＵ（中央処理装置）とを備えた１つのコンピュータによって構成される。 [Configuration of secondary battery system]
FIG. 2 is a schematic configuration diagram of the secondary battery system 100 according to the present embodiment. The secondary battery system 100 includes a laminated body 11 (see FIG. 1), an impedance measuring unit 120, an electrolytic solution leakage determining unit 140, and an alarm unit 200. FIG. 2 shows two stacked power generation elements 20 as a part of the laminated body 11. The impedance measurement unit 120 and the electrolyte leakage determination unit 140 are described separately in two blocks for convenience, but these parts are usually provided with a semiconductor memory such as a RAM or ROM and a CPU (central processing unit). It consists of one computer.

積層体１１は、正極集電箔３１ａと負極集電箔３１ｂとが積層された集電体３１の、正極側に正極活物質層３２ａ、負極側に負極活物質層３２ｂが形成された双極電極３５を、電解液が含まれるセパレータ４０を介して直列に接続してなる。 The laminate 11 is a bipolar electrode in which a positive electrode active material layer 32a is formed on the positive electrode side and a negative electrode active material layer 32b is formed on the negative electrode side of the current collector 31 in which a positive electrode current collecting foil 31a and a negative electrode collecting foil 31b are laminated. 35 is connected in series via a separator 40 containing an electrolytic solution.

インピーダンス計測部１２０は、双極電極３５の正極集電箔３１ａと負極集電箔３１ｂとの間のインピーダンスを計測する。インピーダンスの計測は、セル電圧検出線１２５ａおよび１２５ｂを介して、正極集電箔３１ａと負極集電箔３１ｂとの間に、２つの異なる周波数の交流電圧（高周波電圧と低周波電圧）を、交互に印加することで計測する。 The impedance measuring unit 120 measures the impedance between the positive electrode current collecting foil 31a and the negative electrode current collecting foil 31b of the bipolar electrode 35. Impedance is measured by alternating two different frequency AC voltages (high frequency voltage and low frequency voltage) between the positive electrode collector foil 31a and the negative electrode current collector foil 31b via the cell voltage detection lines 125a and 125b. It is measured by applying it to.

電解液漏洩判断部１４０は、インピーダンス計測部１２０によって計測されたインピーダンスのコンデンサ成分（虚数成分値）と抵抗成分（実数成分値）とを用いて、正極集電箔３１ａと負極集電箔３１ｂとの間の電解液の漏洩を判断する。正極集電箔３１ａと負極集電箔３１ｂとの間で電解液が漏洩しているときには、高周波電圧と低周波電圧とを印加したときに計測されるインピーダンスに、それぞれ異なるコンデンサ成分と抵抗成分とが存在する。電解液漏洩判断部１４０はこれらのコンデンサ成分と抵抗成分とを用いて電解液の漏洩を検知する。 The electrolyte leakage determination unit 140 uses the capacitor component (imaginary number component value) and the resistance component (real number component value) of the impedance measured by the impedance measurement unit 120 to form a positive electrode current collector foil 31a and a negative electrode current collector foil 31b. Determine the leakage of electrolyte between. When the electrolytic solution leaks between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, the impedance measured when a high frequency voltage and a low frequency voltage are applied has different capacitor components and resistance components, respectively. Exists. The electrolytic solution leakage determination unit 140 detects the leakage of the electrolytic solution by using these capacitor components and resistance components.

警報部２００は、電解液漏洩判断部１４０によって電解液の漏洩が検知されると、音、光、振動等、人間の五感で検知可能な態様で警報を出力する。本実施形態では、ワーニングランプを点灯させている。 When the electrolytic solution leakage determination unit 140 detects the electrolytic solution leakage, the alarm unit 200 outputs an alarm in a manner that can be detected by the five human senses, such as sound, light, and vibration. In this embodiment, the warning lamp is turned on.

図３Ａは、図２のインピーダンス計測部１２０のブロック図である。インピーダンス計測部１２０は、高周波電圧出力部１２２、低周波電圧出力部１２４、虚数成分値計測部１２６、および実数成分値計測部１２８を有する。 FIG. 3A is a block diagram of the impedance measuring unit 120 of FIG. The impedance measurement unit 120 includes a high frequency voltage output unit 122, a low frequency voltage output unit 124, an imaginary number component value measurement unit 126, and a real number component value measurement unit 128.

高周波電圧出力部１２２は、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間（図２参照）に１０００Ｈｚの高周波電圧を印加する。本実施形態では、高周波電圧として１０００Ｈｚの周波数の交流電圧を選択しているが、この周波数には限られない。 The high frequency voltage output unit 122 applies a high frequency voltage of 1000 Hz between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 (see FIG. 2). In the present embodiment, an AC voltage having a frequency of 1000 Hz is selected as the high frequency voltage, but the frequency is not limited to this.

低周波電圧出力部１２４は、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０Ｈｚの低周波電圧を印加する。本実施形態では、低周波電圧として１０Ｈｚの周波数の交流電圧を選択しているが、この周波数には限られない。 The low frequency voltage output unit 124 applies a low frequency voltage of 10 Hz between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. In the present embodiment, an AC voltage having a frequency of 10 Hz is selected as the low frequency voltage, but the frequency is not limited to this.

虚数成分値計測部１２６は、高周波電圧出力部１２２が集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０００Ｈｚの高周波電圧を印加したときに計測されたインピーダンスの虚数成分値を計測する。また、低周波電圧出力部１２４が集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０Ｈｚの低周波電圧を印加したときに計測されたインピーダンスの虚数成分値を計測する。 The imaginary component value measuring unit 126 has an imaginary component of impedance measured when the high frequency voltage output unit 122 applies a high frequency voltage of 1000 Hz between the positive electrode current collecting foil 31a and the negative electrode current collecting foil 31b of the current collector 31. Measure the value. Further, the low frequency voltage output unit 124 measures the imaginary component value of the impedance measured when a low frequency voltage of 10 Hz is applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. ..

実数成分値計測部１２８は、高周波電圧出力部１２２が集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０００Ｈｚの高周波電圧を印加したときに計測されたインピーダンスの実数成分値を計測する。また、低周波電圧出力部１２４が集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０Ｈｚの低周波電圧を印加したときに計測されたインピーダンスの実数成分値を計測する。 The real number component value measuring unit 128 is the real number component of the impedance measured when the high frequency voltage output unit 122 applies a high frequency voltage of 1000 Hz between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. Measure the value. Further, the low frequency voltage output unit 124 measures the real number component value of the impedance measured when a low frequency voltage of 10 Hz is applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. ..

図３Ｂは、図２の電解液漏洩判断部１４０のブロック図である。電解液漏洩判断部１４０は、虚数成分値記憶部１４２、実数成分値記憶部１４４、および比較判断部１４６を有する。 FIG. 3B is a block diagram of the electrolytic solution leakage determination unit 140 of FIG. The electrolytic solution leakage determination unit 140 includes an imaginary number component value storage unit 142, a real number component value storage unit 144, and a comparison determination unit 146.

虚数成分値記憶部１４２は、虚数成分値計測部１２６が計測した、高周波電圧および低周波電圧印加時の、それぞれのインピーダンスの虚数成分値を記憶する。 The imaginary component value storage unit 142 stores the imaginary component values of the respective impedances measured by the imaginary component value measurement unit 126 when the high frequency voltage and the low frequency voltage are applied.

実数成分値記憶部１４４は、実数成分値計測部１２８が計測した、高周波電圧および低周波電圧印加時の、それぞれのインピーダンスの実数成分値を記憶する。 The real number component value storage unit 144 stores the real number component values of the respective impedances measured by the real number component value measurement unit 128 when the high frequency voltage and the low frequency voltage are applied.

比較判断部１４６は、虚数成分値記憶部１４２に記憶されている、高周波電圧および低周波電圧印加時の、それぞれのインピーダンスの虚数成分値を比較する。また、実数成分値記憶部１４４に記憶されている、高周波電圧および低周波電圧印加時の、それぞれのインピーダンスの実数成分値を比較する。虚数成分値の比較結果、実数成分値の比較結果から、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間の電解液の漏洩の有無を判断する。 The comparison determination unit 146 compares the imaginary component values of the respective impedances stored in the imaginary component value storage unit 142 when the high frequency voltage and the low frequency voltage are applied. Further, the real number component values of the respective impedances stored in the real number component value storage unit 144 when the high frequency voltage and the low frequency voltage are applied are compared. From the comparison result of the imaginary number component value and the comparison result of the real number component value, it is determined whether or not the electrolytic solution leaks between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31.

［電解液の漏洩の検出原理］
図４Ａは、電解液が漏洩していない場合の集電体３１の状態を示す図であり、図４Ｂは、電解液が漏洩していない場合の等価回路図である。また、図５Ａは、電解液が漏洩している場合の集電体３１の状態を示す図であり、図５Ｂは、電解液が漏洩している場合の等価回路図である。 [Principle of detecting electrolyte leakage]
FIG. 4A is a diagram showing a state of the current collector 31 when the electrolytic solution does not leak, and FIG. 4B is an equivalent circuit diagram when the electrolytic solution does not leak. Further, FIG. 5A is a diagram showing a state of the current collector 31 when the electrolytic solution is leaking, and FIG. 5B is an equivalent circuit diagram when the electrolytic solution is leaking.

図４Ａに示すように、正極集電箔３１ａと負極集電箔３１ｂとの間に電解液が漏洩していなければ、正極集電箔３１ａと負極集電箔３１ｂの全面が互いに密着している。このため、正極集電箔３１ａと負極集電箔３１ｂとの間には抵抗成分のみが存在しコンデンサ成分は存在しない。ただし、正極集電箔３１ａと負極集電箔３１ｂとの間に微小な隙間が存在することがあるので、この場合には、微小なコンデンサ成分が存在する。 As shown in FIG. 4A, if the electrolytic solution does not leak between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, the entire surfaces of the positive electrode current collector foil 31a and the negative electrode current collector foil 31b are in close contact with each other. .. Therefore, only the resistance component exists between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, and the capacitor component does not exist. However, since there may be a minute gap between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, in this case, a minute capacitor component is present.

本実施形態に係る二次電池システム１００は、インピーダンス計測部１２０（図２参照）からセル電圧検出線１２５ａおよび１２５ｂを介して、正極集電箔３１ａと負極集電箔３１ｂとの間に高周波電圧と低周波電圧を印加する。正極集電箔３１ａと負極集電箔３１ｂとの間に電解液が漏洩していなければ、コンデンサ成分はほとんど存在しないので、セル電圧検出線１２５ａおよび１２５ｂ間に流れる電流は、印加された電圧と同位相の電流となる。 The secondary battery system 100 according to the present embodiment has a high frequency voltage between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b from the impedance measuring unit 120 (see FIG. 2) via the cell voltage detection lines 125a and 125b. And apply a low frequency voltage. If the electrolytic solution does not leak between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, there is almost no capacitor component, so the current flowing between the cell voltage detection lines 125a and 125b is the applied voltage. The currents are in phase.

このため、電解液が漏洩していない場合の正極集電箔３１ａと負極集電箔３１ｂとの間の等価回路は、図４Ｂのように表される。この等価回路において、直列に接続されている抵抗Ｒａは、正極集電箔３１ａの単位長さ当たりの抵抗を示す。また、直列に接続されている抵抗Ｒｂは、負極集電箔３１ｂの単位長さ当たりの抵抗を示す。さらに、抵抗Ｒａと抵抗Ｒｂとの間で並列に接続されている抵抗Ｒｄは、正極集電箔３１ａと負極集電箔３１ｂとの間における各部の接触抵抗を示す。 Therefore, the equivalent circuit between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b when the electrolytic solution does not leak is represented as shown in FIG. 4B. In this equivalent circuit, the resistance Ra connected in series indicates the resistance per unit length of the positive electrode current collector foil 31a. Further, the resistance Rb connected in series indicates the resistance per unit length of the negative electrode current collector foil 31b. Further, the resistance Rd connected in parallel between the resistance Ra and the resistance Rb indicates the contact resistance of each part between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b.

電解液が漏洩していない場合の等価回路は、図４Ｂのように、抵抗成分のみで表されるので、インピーダンス計測部１２０によって計測されるインピーダンスは、抵抗成分、すなわち実数成分値のみを有するインピーダンスとなる。つまり、高周波電圧が印加されたときの図４Ｂに示した等価回路の高周波インピーダンスＺ１がＲ１であり、低周波電圧が印加されたときの、図４Ｂに示した等価回路の低周波インピーダンスＺ２がＲ２であれば、インピーダンス計測部１２０は、高周波電圧を印加したときの実数成分値としてＲ１、低周波電圧を印加したときの実数成分値としてＲ２をそれぞれ計測する。 Since the equivalent circuit when the electrolytic solution does not leak is represented only by the resistance component as shown in FIG. 4B, the impedance measured by the impedance measuring unit 120 is the impedance having only the resistance component, that is, the real number component value. It becomes. That is, the high frequency impedance Z1 of the equivalent circuit shown in FIG. 4B when the high frequency voltage is applied is R1, and the low frequency impedance Z2 of the equivalent circuit shown in FIG. 4B when the low frequency voltage is applied is R2. If so, the impedance measuring unit 120 measures R1 as a real component value when a high frequency voltage is applied and R2 as a real component value when a low frequency voltage is applied.

一方、図５Ａに示すように、正極集電箔３１ａと負極集電箔３１ｂとの間で電解液６０が漏洩していれば、正極集電箔３１ａと負極集電箔３１ｂとが直接密着している部分と、正極集電箔３１ａと負極集電箔３１ｂとの間に電解液６０を介在している部分とが存在する。このため、正極集電箔３１ａと負極集電箔３１ｂとの間には抵抗成分とコンデンサ成分の両方が存在する。 On the other hand, as shown in FIG. 5A, if the electrolytic solution 60 leaks between the positive electrode collecting foil 31a and the negative electrode collecting foil 31b, the positive electrode collecting foil 31a and the negative electrode collecting foil 31b are in direct contact with each other. There is a portion where the electrolytic solution 60 is interposed between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. Therefore, both a resistance component and a capacitor component are present between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b.

インピーダンス計測部１２０は、セル電圧検出線１２５ａおよび１２５ｂを介して、正極集電箔３１ａと負極集電箔３１ｂとの間に高周波電圧と低周波電圧を印加する。正極集電箔３１ａと負極集電箔３１ｂとの間に電解液６０が漏洩していると、抵抗成分とコンデンサ成分の両方が存在するので、セル電圧検出線１２５ａおよび１２５ｂ間に流れる電流は、印加された電圧に対して位相差を持つ電流となる。 The impedance measurement unit 120 applies a high frequency voltage and a low frequency voltage between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b via the cell voltage detection lines 125a and 125b. When the electrolytic solution 60 leaks between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, both the resistance component and the capacitor component are present, so that the current flowing between the cell voltage detection lines 125a and 125b is increased. It is a current with a phase difference with respect to the applied voltage.

このため、電解液６０が漏洩している場合の正極集電箔３１ａと負極集電箔３１ｂとの間の等価回路は、図５Ｂのように表される。この等価回路において、直列に接続されている抵抗Ｒａは、正極集電箔３１ａの単位長さ当たりの抵抗を示す。また、直列に接続されている抵抗Ｒｂは、負極集電箔３１ｂの単位長さ当たりの抵抗を示す。さらに、抵抗Ｒａと抵抗Ｒｂとの間で並列に接続されている抵抗Ｒｄは正極集電箔３１ａと負極集電箔３１ｂとの間における各部の接触抵抗を示す。また、抵抗Ｒｄと並列に接続されているコンデンサ成分Ｃは、正極集電箔３１ａと負極集電箔３１ｂとの間に存在する電解液６０が正極集電箔３１ａと負極集電箔３１ｂとの間に形成するコンデンサ成分を示す。 Therefore, the equivalent circuit between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b when the electrolytic solution 60 is leaking is shown as shown in FIG. 5B. In this equivalent circuit, the resistance Ra connected in series indicates the resistance per unit length of the positive electrode current collector foil 31a. Further, the resistance Rb connected in series indicates the resistance per unit length of the negative electrode current collector foil 31b. Further, the resistance Rd connected in parallel between the resistance Ra and the resistance Rb indicates the contact resistance of each part between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. Further, in the capacitor component C connected in parallel with the resistor Rd, the electrolytic solution 60 existing between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b is the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. The capacitor components formed between them are shown.

電解液６０が漏洩している場合の等価回路は、図５Ｂのように、抵抗成分とコンデンサ成分との両方の成分で表されるので、インピーダンス計測部１２０によって計測されるインピーダンスは、実数成分値と虚数成分値の両方を有するインピーダンスとなる。つまり、高周波電圧が印加されたときの図５Ｂに示した等価回路の高周波インピーダンスＺ１がＲ１＋ｊＸ１であり、低周波電圧が印加されたときの、図５Ｂに示した等価回路の低周波インピーダンスＺ２がＲ２＋ｊＸ２であれば、インピーダンス計測部１２０は、高周波電圧を印加したときの、実数成分値としてＲ１、虚数成分値としてｊＸ１、低周波電圧を印加したときの、実数成分値としてＲ２、虚数成分値としてｊＸ２をそれぞれ計測することになる。 Since the equivalent circuit when the electrolytic solution 60 is leaking is represented by both the resistance component and the capacitor component as shown in FIG. 5B, the impedance measured by the impedance measuring unit 120 is a real number component value. And the impedance that has both the imaginary component value. That is, the high frequency impedance Z1 of the equivalent circuit shown in FIG. 5B when the high frequency voltage is applied is R1 + jX1, and the low frequency impedance Z2 of the equivalent circuit shown in FIG. 5B when the low frequency voltage is applied is R2 + jX2. If so, the impedance measurement unit 120 has R1 as a real component value when a high frequency voltage is applied, jX1 as an imaginary component value, R2 as a real component value when a low frequency voltage is applied, and jX2 as an imaginary component value. Will be measured respectively.

したがって、電解液６０が漏洩している場合には、高周波電圧印加時の高周波インピーダンスＺ１の実数成分値および虚数成分値と低周波電圧印加時の低周波インピーダンスＺ２の実数成分値および虚数成分値は、電解液６０が漏洩してない場合とは大きく異なってくる。また、高周波電圧印加時の高周波インピーダンスＺ１の実数成分値および虚数成分値の大きさは、低周波電圧印加時の低周波インピーダンスＺ２の実数成分値および虚数成分値のそれぞれの大きさよりも小さくなる。等価回路のコンデンサ成分Ｃのみによる交流抵抗は１／ｊ２πｆＣで表されるため、周波数ｆの大きい高周波の交流抵抗の方が低周波の交流抵抗よりも小さくなるからである。本実施形態に係る二次電池システム１００では、これらの違いを計測することによって、電解液６０の漏洩を検知している。 Therefore, when the electrolytic solution 60 is leaking, the real number component value and the imaginary number component value of the high frequency impedance Z1 when the high frequency voltage is applied and the real number component value and the imaginary number component value of the low frequency impedance Z2 when the low frequency voltage is applied are , It is significantly different from the case where the electrolytic solution 60 does not leak. Further, the magnitudes of the real component value and the imaginary component value of the high frequency impedance Z1 when the high frequency voltage is applied are smaller than the respective magnitudes of the real component value and the imaginary component value of the low frequency impedance Z2 when the low frequency voltage is applied. This is because the AC resistance due to only the capacitor component C of the equivalent circuit is represented by 1 / j2πfC, so that the high frequency AC resistance having a large frequency f is smaller than the low frequency AC resistance. In the secondary battery system 100 according to the present embodiment, leakage of the electrolytic solution 60 is detected by measuring these differences.

［二次電池システムの動作］
図６は、本実施形態に係る二次電池システム１００の動作フローチャートである。以下に、図２から図９を参照して、二次電池システム１００の動作を詳細に説明する。 [Operation of secondary battery system]
FIG. 6 is an operation flowchart of the secondary battery system 100 according to the present embodiment. Hereinafter, the operation of the secondary battery system 100 will be described in detail with reference to FIGS. 2 to 9.

図６に示すように、インピーダンス計測部１２０は、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間のインピーダンスを計測する（Ｓ１００）。 As shown in FIG. 6, the impedance measuring unit 120 measures the impedance between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 (S100).

具体的には、図７に示すように、高周波電圧出力部１２２が、セル電圧検出線１２５ａおよび１２５ｂを介して、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０００Ｈｚの高周波電圧を印加する（Ｓ１０１）。これにより、正極集電箔３１ａと負極集電箔３１ｂとの間に高周波電流が流れる。 Specifically, as shown in FIG. 7, the high-frequency voltage output unit 122 is connected between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 via the cell voltage detection lines 125a and 125b. A high frequency voltage of 1000 Hz is applied (S101). As a result, a high frequency current flows between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b.

インピーダンス計測部１２０は、高周波電圧を印加した時に流れた高周波電流の実効値（大きさ）と高周波電圧に対する高周波電流の位相差とから、高周波インピーダンスＺ１を計測する。なお、高周波インピーダンスとは、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波電圧を印加したときの、正極集電箔３１ａと負極集電箔３１ｂとの間のインピーダンスである。虚数成分値計測部１２６は、高周波インピーダンスＺ１の虚数成分値ｊＸ１を計測し、実数成分値計測部１２８は、高周波インピーダンスＺ１の実数成分値Ｒ１を計測する。 The impedance measuring unit 120 measures the high frequency impedance Z1 from the effective value (magnitude) of the high frequency current flowing when the high frequency voltage is applied and the phase difference of the high frequency current with respect to the high frequency voltage. The high-frequency impedance is defined as the distance between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b when a high-frequency voltage is applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. Impedance. The imaginary component value measuring unit 126 measures the imaginary component value jX1 of the high frequency impedance Z1, and the real number component value measuring unit 128 measures the real component value R1 of the high frequency impedance Z1.

電解液漏洩判断部１４０は、虚数成分値計測部１２６によって計測された高周波インピーダンスＺ１の虚数成分値ｊＸ１を虚数成分値記憶部１４２に記憶させ、また、その実数成分値Ｒ１を実数成分値記憶部１４４に記憶させる（Ｓ１０２）。 The electrolytic solution leakage determination unit 140 stores the imaginary number component value jX1 of the high frequency impedance Z1 measured by the imaginary number component value measurement unit 126 in the imaginary number component value storage unit 142, and stores the real number component value R1 in the real number component value storage unit. It is stored in 144 (S102).

次に、低周波電圧出力部１２４が、セル電圧検出線１２５ａおよび１２５ｂを介して、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に１０Ｈｚの低周波電圧を印加する（Ｓ１０３）。これにより、正極集電箔３１ａと負極集電箔３１ｂとの間に低周波電流が流れる。 Next, the low frequency voltage output unit 124 applies a low frequency voltage of 10 Hz between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 via the cell voltage detection lines 125a and 125b. (S103). As a result, a low frequency current flows between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b.

インピーダンス計測部１２０は、低周波電圧を印加した時に流れた低周波電流の実効値（大きさ）と低周波電圧に対する低周波電流の位相差とから、低周波インピーダンスＺ２を計測する。なお、低周波インピーダンスとは、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に低周波電圧を印加したときの、正極集電箔３１ａと負極集電箔３１ｂとの間のインピーダンスである。虚数成分値計測部１２６は、低周波インピーダンスＺ２の虚数成分値ｊＸ２を計測し、実数成分値計測部１２８は、低周波インピーダンスＺ２の実数成分値Ｒ２を計測する。 The impedance measuring unit 120 measures the low frequency impedance Z2 from the effective value (magnitude) of the low frequency current flowing when the low frequency voltage is applied and the phase difference of the low frequency current with respect to the low frequency voltage. The low frequency impedance refers to the positive electrode current collector foil 31a and the negative electrode current collector foil 31b when a low frequency voltage is applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31. Impedance between. The imaginary component value measuring unit 126 measures the imaginary component value jX2 of the low frequency impedance Z2, and the real number component value measuring unit 128 measures the real number component value R2 of the low frequency impedance Z2.

電解液漏洩判断部１４０は、虚数成分値計測部１２６によって計測された低周波インピーダンスＺ２の虚数成分値ｊＸ２を虚数成分値記憶部１４２に記憶させ、また、その実数成分値Ｒ２を実数成分値記憶部１４４に記憶させる（Ｓ１０４）。 The electrolytic solution leakage determination unit 140 stores the imaginary number component value jX2 of the low frequency impedance Z2 measured by the imaginary number component value measurement unit 126 in the imaginary number component value storage unit 142, and stores the real number component value R2 in the real number component value storage unit 142. It is stored in the unit 144 (S104).

図８Ａは、電解液が漏洩していない場合のコールコールプロット図である。図８Ｂは、電解液が漏洩している場合のコールコールプロット図である。コールコールプロット図は、いろいろな周波数でインピーダンスの実数成分値と虚数成分値を演算し、それぞれを横軸、縦軸にプロットすることによって得られる図である。 FIG. 8A is a call call plot diagram when the electrolytic solution does not leak. FIG. 8B is a call call plot diagram when the electrolytic solution is leaking. The call-call plot diagram is a diagram obtained by calculating the real number component value and the imaginary number component value of impedance at various frequencies and plotting each on the horizontal axis and the vertical axis.

本実施形態の場合、電解液６０が漏洩していない場合の、高周波インピーダンスＺ１がＲ１であり、低周波インピーダンスＺ２がＲ２であるので、電解液６０が漏洩していない場合のコールコールプロット図としては、たとえば図８Ａのようなものになる。また、電解液６０が漏洩している場合の、高周波インピーダンスＺ１がＲ１＋ｊＸ１であり、低周波インピーダンスＺ２がＲ２＋ｊＸ２であるので、電解液６０が漏洩している場合のコールコールプロット図としては、たとえば図８Ｂのようなものになる。 In the case of this embodiment, since the high frequency impedance Z1 is R1 and the low frequency impedance Z2 is R2 when the electrolytic solution 60 is not leaking, as a call call plot diagram when the electrolytic solution 60 is not leaking. Is, for example, as shown in FIG. 8A. Further, since the high frequency impedance Z1 is R1 + jX1 and the low frequency impedance Z2 is R2 + jX2 when the electrolytic solution 60 is leaking, as a call call plot diagram when the electrolytic solution 60 is leaking, for example, FIG. It will be something like 8B.

図６に戻って、電解液漏洩判断部１４０は、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間で電解液６０が漏洩しているか否かを判断する（Ｓ１１０）。 Returning to FIG. 6, the electrolytic solution leakage determination unit 140 determines whether or not the electrolytic solution 60 is leaking between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 (S110). ..

具体的には、図９に示すように、電解液漏洩判断部１４０の比較判断部１４６が、虚数成分値記憶部１４２に記憶されている高周波および低周波のインピーダンスＺ１、Ｚ２の虚数成分値ｊＸ１とｊＸ２との大きさを比較する（Ｓ１１１）。 Specifically, as shown in FIG. 9, the comparison determination unit 146 of the electrolytic solution leakage determination unit 140 has the imaginary number component values jX1 of the high-frequency and low-frequency impedances Z1 and Z2 stored in the imaginary number component value storage unit 142. And jX2 are compared in size (S111).

比較の結果、高周波の虚数成分値ｊＸ１が低周波の虚数成分値ｊＸ２よりも大きいか等しければ（Ｓ１１２：ＹＥＳ）、次のステップの処理に進み、高周波の虚数成分値ｊＸ１が低周波の虚数成分値ｊＸ２未満であれば（Ｓ１１２：ＮＯ）、電解液６０が漏洩していると判断する（Ｓ１１６）。 As a result of comparison, if the high frequency imaginary component value jX1 is larger than or equal to the low frequency imaginary component value jX2 (S112: YES), the process proceeds to the next step, and the high frequency imaginary component value jX1 is the low frequency imaginary component. If the value is less than jX2 (S112: NO), it is determined that the electrolytic solution 60 is leaking (S116).

次に、電解液漏洩判断部１４０の比較判断部１４６が、実数成分値記憶部１４４に記憶されている高周波および低周波のインピーダンスＺ１、Ｚ２の実数成分値Ｒ１とＲ２との大きさを比較する（Ｓ１１３）。 Next, the comparison determination unit 146 of the electrolyte leakage determination unit 140 compares the magnitudes of the real number component values R1 and R2 of the high-frequency and low-frequency impedances Z1 and Z2 stored in the real number component value storage unit 144. (S113).

比較の結果、高周波の実数成分値Ｒ１が低周波の実数成分値Ｒ２よりも大きいか等しければ（Ｓ１１４：ＹＥＳ）、電解液６０が漏洩していないと判断する（Ｓ１１５）。また、高周波の実数成分値Ｒ１が低周波の実数成分値Ｒ２未満であれば（Ｓ１１４：ＮＯ）、電解液６０が漏洩していると判断する（Ｓ１１６）。 As a result of comparison, if the high-frequency real number component value R1 is larger than or equal to the low-frequency real number component value R2 (S114: YES), it is determined that the electrolytic solution 60 has not leaked (S115). Further, if the high frequency real number component value R1 is less than the low frequency real number component value R2 (S114: NO), it is determined that the electrolytic solution 60 is leaking (S116).

つまり、本実施形態では、高周波の虚数成分値ｊＸ１が低周波の虚数成分値ｊＸ２未満のとき、または、高周波の実数成分値Ｒ１が低周波の実数成分値Ｒ２未満のとき、のいずれかの場合に、電解液６０が漏洩していると判断している。 That is, in the present embodiment, either when the high frequency imaginary component value jX1 is less than the low frequency imaginary component value jX2, or when the high frequency real number component value R1 is less than the low frequency real number component value R2. It is determined that the electrolytic solution 60 is leaking.

また、本実施形態では、高周波の虚数成分値ｊＸ１が低周波の虚数成分値ｊＸ２よりも大きいか等しいとき、および、高周波の実数成分値Ｒ１が低周波の実数成分値Ｒ２よりも大きいか等しいときに、電解液６０が漏洩していないと判断している。 Further, in the present embodiment, when the high frequency imaginary component value jX1 is larger or equal to the low frequency imaginary component value jX2, and when the high frequency real number component value R1 is larger than or equal to the low frequency real number component value R2. In addition, it is determined that the electrolytic solution 60 has not leaked.

しかし、高周波の虚数成分値ｊＸ１が低周波の虚数成分値ｊＸ２よりも大きいか等しければ、高周波の実数成分値Ｒ１と低周波の実数成分値Ｒ２との比較を行うまでもなく、電解液６０が漏洩していないと判断しても良い。 However, if the high frequency imaginary component value jX1 is larger than the low frequency imaginary component value jX2, the electrolytic solution 60 does not need to be compared between the high frequency real number component value R1 and the low frequency real number component value R2. It may be determined that there is no leakage.

また、本実施形態では、高周波の虚数成分値ｊＸ１と低周波の虚数成分値ｊＸ２との比較を先にし、高周波の実数成分値Ｒ１と低周波の実数成分値Ｒ２の比較を後にしているが、この比較の順番は逆にしても良い。 Further, in the present embodiment, the comparison between the high-frequency imaginary component value jX1 and the low-frequency imaginary component value jX2 is performed first, and the high-frequency real number component value R1 and the low-frequency real number component value R2 are compared later. , The order of this comparison may be reversed.

この順番を逆にした場合、高周波の実数成分値Ｒ１が低周波の実数成分値Ｒ２よりも大きいか等しければ、高周波の虚数成分値ｊＸ１と低周波の虚数成分値ｊＸ２との比較を行うまでもなく、電解液６０が漏洩していないと判断しても良い。 When this order is reversed, if the high frequency real number component value R1 is larger than the low frequency real number component value R2, even if the high frequency imaginary component value jX1 and the low frequency imaginary component value jX2 are compared. It may be determined that the electrolytic solution 60 has not leaked.

図６に戻って、電解液漏洩判断部１４０は、電解液６０が漏洩していると判断したときには（Ｓ１２０：ＹＥＳ）、警報部２００のワーニングランプを点灯させる。ワーニングランプの点灯によって、二次電池１０に異常が生じていることがわかる。一方、電解液６０が漏洩していないと判断したときには（Ｓ１２０：ＮＯ）、Ｓ１００のステップの処理に戻って、Ｓ１００、Ｓ１１０、Ｓ１２０のステップの処理を繰り返す。 Returning to FIG. 6, when the electrolytic solution leakage determination unit 140 determines that the electrolytic solution 60 is leaking (S120: YES), the warning lamp of the alarm unit 200 is turned on. By lighting the warning lamp, it can be seen that an abnormality has occurred in the secondary battery 10. On the other hand, when it is determined that the electrolytic solution 60 has not leaked (S120: NO), the process returns to the process of the step of S100, and the process of the steps of S100, S110, and S120 is repeated.

なお、以上の実施形態では、高周波の虚数成分値ｊＸ１と低周波の虚数成分値ｊＸ２、高周波の実数成分値Ｒ１と低周波の実数成分値Ｒ２とを計測し、虚数成分値同士、実数成分値同士を比較することで電解液６０の漏洩の有無を判断している。しかし、図８Ａ、図８Ｂに示したコールコールプロット図における、高周波の虚数成分値ｊＸ１、実数成分値Ｒ１、低周波の虚数成分値ｊＸ２、低周波の実数成分値Ｒ２のプロット位置だけで、電解液６０の漏洩の有無を判断しても良い。 In the above embodiment, the high frequency imaginary component value jX1 and the low frequency imaginary component value jX2, the high frequency real number component value R1 and the low frequency real number component value R2 are measured, and the imaginary number component values and the real number component values are measured. The presence or absence of leakage of the electrolytic solution 60 is determined by comparing the two. However, in the call call plots shown in FIGS. 8A and 8B, electrolysis is performed only at the plot positions of the high frequency imaginary component value jX1, the real number component value R1, the low frequency imaginary component value jX2, and the low frequency real number component value R2. The presence or absence of leakage of the liquid 60 may be determined.

また、本実施形態では、集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間の電解液６０の漏洩のみを検知したが、たとえば、積層体１１の上下両端の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波および低周波の電圧を印加して、積層体１１を構成する発電要素２０のどこかで電解液６０の漏洩があることを検知するようにしても良い。この場合、正常な積層体１１の高周波の虚数成分値ｊＸ１と低周波の虚数成分値ｊＸ２、高周波の実数成分値Ｒ１と低周波の実数成分値Ｒ２とを計測しておき、この計測しておいた各成分値との比較において、電解液６０の漏洩の有無を検知するようにしてもよい。 Further, in the present embodiment, only leakage of the electrolytic solution 60 between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 is detected. For example, the positive electrode current collectors at the upper and lower ends of the laminated body 11 are detected. High-frequency and low-frequency voltages are applied between the foil 31a and the negative electrode current collector foil 31b so as to detect that the electrolytic solution 60 leaks somewhere in the power generation element 20 constituting the laminated body 11. Is also good. In this case, the high frequency imaginary component value jX1 and the low frequency imaginary component value jX2, the high frequency real number component value R1 and the low frequency real number component value R2 of the normal laminated body 11 are measured and measured. The presence or absence of leakage of the electrolytic solution 60 may be detected in comparison with each component value.

さらに、本実施形態では、発明の内容の理解を容易にするために、１つの集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波および低周波の電圧を印加して電解液６０の漏洩を検知する場合について記載した。実際には二次電池１０の安全性と信頼性を確保するために、積層体１１を構成する全ての集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波および低周波の電圧を印加して電解液６０の漏洩を検知することが好ましい。しかし、全ての集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波および低周波の電圧を印加するのではなく、他の集電体３１と比較して、機械的強度の弱そうな位置に存在する集電体３１の正極集電箔３１ａと負極集電箔３１ｂとの間に高周波および低周波の電圧を印加するようにしても良い。 Further, in the present embodiment, in order to facilitate understanding of the content of the invention, high frequency and low frequency voltages are applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of one current collector 31. The case where the leakage of the electrolytic solution 60 is detected is described. Actually, in order to ensure the safety and reliability of the secondary battery 10, high frequency and low frequency are generated between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of all the current collectors 31 constituting the laminated body 11. It is preferable to apply a voltage of a frequency to detect leakage of the electrolytic solution 60. However, instead of applying high-frequency and low-frequency voltages between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of all current collectors 31, it is mechanical as compared with other current collectors 31. High-frequency and low-frequency voltages may be applied between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the current collector 31 existing at a position where the strength is likely to be weak.

以上、本発明に係る二次電池システム１００の実施形態について説明した。この実施形態の効果は、下記の通りである。 The embodiment of the secondary battery system 100 according to the present invention has been described above. The effects of this embodiment are as follows.

本実施形態では、双極電極３５の正極集電箔３１ａと負極集電箔３１ｂとの間のインピーダンスを計測するだけで電解液６０の漏洩が検知できる。このため、発電要素２０間の短絡が防止でき、二次電池１０の安全性および信頼性が確保できる。 In the present embodiment, leakage of the electrolytic solution 60 can be detected only by measuring the impedance between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b of the bipolar electrode 35. Therefore, a short circuit between the power generation elements 20 can be prevented, and the safety and reliability of the secondary battery 10 can be ensured.

本実施形態では、正極集電箔３１ａと負極集電箔３１ｂとを、樹脂または樹脂を含む導電材料で形成している。このため、金属に比較して機械的強度が相対的に弱くなりがちな、樹脂集電体を用いた二次電池１０の安全性および信頼性が確保できる。 In the present embodiment, the positive electrode current collector foil 31a and the negative electrode current collector foil 31b are formed of a resin or a conductive material containing a resin. Therefore, the safety and reliability of the secondary battery 10 using the resin current collector, which tends to be relatively weak in mechanical strength as compared with metal, can be ensured.

本実施形態では、正極集電箔３１ａと負極集電箔３１ｂとの間の高周波インピーダンスＺ１と低周波インピーダンスＺ２を計測し、計測された高周波インピーダンスＺ１の虚数成分値ｊＸ１が低周波インピーダンスＺ２の虚数成分値ｊＸ２未満であれば電解液６０が漏洩していると判断している。このため、正極集電箔３１ａと負極集電箔３１ｂとの間に、高周波電圧および低周波電圧を印加、または高周波電流および低周波電流を流すだけで、電解液６０の漏洩の有無が判断できる。 In the present embodiment, the high frequency impedance Z1 and the low frequency impedance Z2 between the positive voltage collecting foil 31a and the negative frequency collecting foil 31b are measured, and the measured imaginary component value jX1 of the high frequency impedance Z1 is the imaginary number of the low frequency impedance Z2. If the component value is less than jX2, it is determined that the electrolytic solution 60 is leaking. Therefore, the presence or absence of leakage of the electrolytic solution 60 can be determined only by applying a high frequency voltage and a low frequency voltage or passing a high frequency current and a low frequency current between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. ..

本実施形態では、計測された高周波インピーダンスＺ１の実数成分値Ｒ１が低周波インピーダンスＺ２の実数成分値Ｒ２未満であれば電解液６０が漏洩していると判断している。このため、正極集電箔３１ａと負極集電箔３１ｂとの間に、高周波電圧および低周波電圧を印加、または高周波電流および低周波電流を流すだけで、電解液６０の漏洩の有無が判断できる。 In the present embodiment, if the measured real number component value R1 of the high frequency impedance Z1 is less than the real number component value R2 of the low frequency impedance Z2, it is determined that the electrolytic solution 60 is leaking. Therefore, the presence or absence of leakage of the electrolytic solution 60 can be determined only by applying a high frequency voltage and a low frequency voltage or passing a high frequency current and a low frequency current between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. ..

本実施形態では、計測された高周波インピーダンスＺ１の虚数成分値ｊＸ１または実数成分値Ｒ１のいずれかが低周波インピーダンスＺ２の虚数成分値ｊＸ２または実数成分値Ｒ２未満であれば電解液６０が漏洩していると判断している。このため、正極集電箔３１ａと負極集電箔３１ｂとの間に、高周波電圧および低周波電圧を印加、または高周波電流および低周波電流を流すだけで、電解液６０の漏洩の有無が判断できる。 In the present embodiment, if either the measured imaginary component value jX1 of the high frequency impedance Z1 or the real number component value R1 is less than the imaginary component value jX2 of the low frequency impedance Z2 or the real number component value R2, the electrolytic solution 60 leaks. I have determined that there is. Therefore, the presence or absence of leakage of the electrolytic solution 60 can be determined only by applying a high frequency voltage and a low frequency voltage or passing a high frequency current and a low frequency current between the positive electrode current collector foil 31a and the negative electrode current collector foil 31b. ..

本実施形態では、正極集電箔３１ａおよび前記負極集電箔３１ｂにそれぞれ接続されている、セル電圧検出線１２５ａ、１２５ｂを用いて、高周波電圧および低周波電圧を印加し、または高周波電流および低周波電流を流している。セル電圧検出線１２５ａ、１２５ｂのいずれか一方は、発電要素２０の電圧を検出するためにあらかじめ用いられているので、１本のセル電圧検出線を追加するだけで、本発明の適用が可能となる。 In the present embodiment, high frequency voltage and low frequency voltage are applied, or high frequency current and low frequency are applied by using cell voltage detection lines 125a and 125b connected to the positive electrode current collector foil 31a and the negative electrode current collector foil 31b, respectively. A frequency current is flowing. Since either one of the cell voltage detection lines 125a and 125b is used in advance for detecting the voltage of the power generation element 20, the present invention can be applied only by adding one cell voltage detection line. Become.

１０ 二次電池、
１１ 積層体、
１２ 外装体、
２０ 発電要素、
３１ 集電体、
３１ａ 正極集電箔、
３１ｂ 負極集電箔、
３２ 電極活物質層、
３２ａ 正極活物質層、
３２ｂ 負極活物質層、
３４ａ 正極集電板、
３４ｂ 負極集電板、
３５ 双極電極、
４０ セパレータ、
５０ シール部、
６０ 電解液、
１００ 二次電池システム、
１２０ インピーダンス計測部、
１２２ 高周波電圧出力部、
１２４ 低周波電圧出力部、
１２５ａ、１２５ｂ セル電圧検出線、
１２６ 虚数成分値計測部、
１２８ 実数成分値計測部、
１４０ 電解液漏洩判断部、
１４２ 虚数成分値
１４６ 比較判断部、
２００ 警報部。 10 Rechargeable battery,
11 laminated body,
12 exterior body,
20 power generation elements,
31 Current collector,
31a Positive electrode current collector foil,
31b Negative current collector foil,
32 Electrode active material layer,
32a Positive electrode active material layer,
32b Negative electrode active material layer,
34a Positive current collector plate,
34b Negative current collector plate,
35 bipolar electrode,
40 separator,
50 Seal part,
60 electrolyte,
100 rechargeable battery system,
120 Impedance measurement unit,
122 High frequency voltage output unit,
124 Low frequency voltage output unit,
125a, 125b cell voltage detection line,
126 Imaginary component value measuring unit,
128 Real number component value measuring unit,
140 Electrolyte Leakage Judgment Unit,
142 Imaginary component value 146 Comparison judgment unit,
200 Alarm unit.

Claims (7)

正極集電箔と負極集電箔とが積層された集電体の、正極側に正極活物質層、負極側に負極活物質層が形成された双極電極を、電解液が含まれるセパレータを介して直列に複数接続した積層体を有し、前記正極集電箔、前記正極活物質層、前記セパレータ、前記負極活物質層および前記負極集電箔によって発電要素が形成され、前記発電要素の端部に、前記正極活物質層、前記負極活物質層およびセパレータの周囲を封止するシール部が設けられている二次電池と、
隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間のインピーダンスを計測するインピーダンス計測部と、
計測された前記インピーダンスを用いて、前記セパレータに含まれる電解液が、前記正極活物質層および前記正極集電箔、または前記負極活物質層および前記負極集電箔から、隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間に漏洩したことを判断する電解液漏洩判断部と、
を有する、二次電池システム。 A bipolar electrode having a positive electrode active material layer formed on the positive electrode side and a negative electrode active material layer formed on the negative electrode side of a current collector in which a positive electrode current collector foil and a negative electrode current collector foil are laminated is passed through a separator containing an electrolytic solution. A power generation element is formed by the positive electrode current collector foil , the positive electrode active material layer, the separator, the negative electrode active material layer, and the negative electrode current collector foil, and the end of the power generation element is formed. A secondary battery provided with a sealing portion for sealing the periphery of the positive electrode active material layer, the negative electrode active material layer, and the separator.
An impedance measuring unit that measures the impedance between the positive electrode current collector foil and the negative electrode current collector foil that are adjacent to each other of the two adjacent power generation elements .
Using the measured impedance, the electrolytic solution contained in the separator is generated from the positive electrode active material layer and the positive electrode current collector foil, or the negative electrode active material layer and the negative electrode current collector foil, and two adjacent power sources. An electrolytic solution leakage determination unit that determines that leakage has occurred between the positive electrode current collector foil and the negative electrode current collector foil that are adjacent to each other .
Has a secondary battery system. 前記正極集電箔は、樹脂または樹脂を含む導電材料で形成されている、請求項１に記載の二次電池システム。 The secondary battery system according to claim 1, wherein the positive electrode current collector foil is made of a resin or a conductive material containing a resin. 前記負極集電箔は、樹脂または樹脂を含む導電材料で形成されている、請求項１または２に記載の二次電池システム。 The secondary battery system according to claim 1 or 2, wherein the negative electrode current collector foil is made of a resin or a conductive material containing a resin. 前記インピーダンス計測部は、
前記隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間に、高周波電圧を印加または高周波電流を流したときの高周波インピーダンスの虚数成分値と低周波電圧を印加または低周波電流を流したときの低周波インピーダンスの虚数成分値とを計測し、
前記電解液漏洩判断部は、
計測された前記高周波インピーダンスの虚数成分値が前記低周波インピーダンスの虚数成分値未満であれば前記電解液が漏洩していると判断する一方、前記高周波インピーダンスの虚数成分値が前記低周波インピーダンスの虚数成分値よりも大きいか等しければ前記電解液が漏洩していないと判断する、請求項１から３のいずれかに記載の二次電池システム。 The impedance measuring unit is
The imaginary component value and low frequency voltage of the high frequency impedance when a high frequency voltage is applied or a high frequency current is passed between the positive positive current collector foil and the negative frequency current collector foil adjacent to each other of the two adjacent power generation elements. Measure the imaginary component value of the low frequency impedance when applied or low frequency current is applied,
The electrolyte leak determination unit is
If the measured imaginary component value of the high frequency impedance is less than the imaginary component value of the low frequency impedance, it is determined that the electrolytic solution is leaking, while the imaginary component value of the high frequency impedance is the imaginary number of the low frequency impedance. The secondary battery system according to any one of claims 1 to 3, wherein it is determined that the electrolytic solution has not leaked if it is larger than or equal to the component value. 前記インピーダンス計測部は、
前記隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間に、高周波電圧を印加または高周波電流を流したときの高周波インピーダンスの実数成分値と低周波電圧を印加または低周波電流を流したときの低周波インピーダンスの実数成分値とを計測し、
前記電解液漏洩判断部は、
計測された前記高周波インピーダンスの実数成分値が前記低周波インピーダンスの実数成分値未満であれば前記電解液が漏洩していると判断する一方、前記高周波インピーダンスの実数成分値が前記低周波インピーダンスの実数成分値よりも大きいか等しければ前記電解液が漏洩していないと判断する、請求項１から３のいずれかに記載の二次電池システム。 The impedance measuring unit is
The real component value and low frequency voltage of the high frequency impedance when a high frequency voltage is applied or a high frequency current is passed between the positive positive current collector foil and the negative frequency current collector foil adjacent to each other of the two adjacent power generation elements. Measure the real component value of the low frequency impedance when applied or low frequency current is applied,
The electrolyte leak determination unit is
If the measured real number component value of the high frequency impedance is less than the real number component value of the low frequency impedance, it is determined that the electrolytic solution is leaking, while the real number component value of the high frequency impedance is the real number of the low frequency impedance. The secondary battery system according to any one of claims 1 to 3, wherein it is determined that the electrolytic solution has not leaked if it is larger than or equal to the component value. 前記インピーダンス計測部は、
前記隣り合う２つの前記発電要素の隣接する前記正極集電箔と前記負極集電箔との間に、高周波電圧を印加または高周波電流を流したときの高周波インピーダンスの虚数成分値と実数成分値を計測するとともに、低周波電圧を印加または低周波電流を流したときの低周波インピーダンスの虚数成分値と実数成分値とを計測し、
前記電解液漏洩判断部は、
計測された前記高周波インピーダンスの虚数成分値または実数成分値のいずれかが前記低周波インピーダンスの虚数成分値または実数成分値未満であれば前記電解液が漏洩していると判断する一方、前記高周波インピーダンスの虚数成分値または実数成分値のいずれかが前記低周波インピーダンスの虚数成分値または実数成分値よりも大きいか等しければ前記電解液が漏洩していないと判断する、請求項１から３のいずれかに記載の二次電池システム。 The impedance measuring unit is
The imaginary component value and the real component value of the high frequency impedance when a high frequency voltage is applied or a high frequency current is passed between the positive voltage collecting foil and the negative frequency collecting foil adjacent to each other of the two adjacent power generation elements. In addition to measuring, measure the imaginary component value and real component value of the low frequency impedance when a low frequency voltage is applied or a low frequency current is passed.
The electrolyte leak determination unit is
If either the measured imaginary component value or the real number component value of the high frequency impedance is less than the imaginary number component value or the real number component value of the low frequency impedance, it is determined that the electrolytic solution is leaking, while the high frequency impedance. If either the imaginary component value or the real number component value of the above is larger than the imaginary number component value or the real number component value of the low frequency impedance, it is determined that the electrolytic solution has not leaked, any of claims 1 to 3. The secondary battery system described in. 前記インピーダンス計測部は、
前記隣り合う２つの前記発電要素の隣接する前記正極集電箔および前記負極集電箔にそれぞれ接続されている、セル電圧検出線を用いて、前記正極集電箔と前記負極集電箔との間に、高周波電圧を印加または高周波電流を流し、低周波電圧を印加または低周波電流を流す、請求項４から６のいずれかに記載の二次電池システム。 The impedance measuring unit is
Using the cell voltage detection line connected to the positive electrode current collector foil and the negative electrode current collector foil adjacent to each other of the two adjacent power generation elements, the positive electrode current collector foil and the negative electrode current collector foil are used. The secondary battery system according to any one of claims 4 to 6, wherein a high-frequency voltage is applied or a high-frequency current is applied between the two, and a low-frequency voltage is applied or a low-frequency current is applied.
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