JP2020087514A - Battery pack - Google Patents

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JP2020087514A
JP2020087514A JP2018214716A JP2018214716A JP2020087514A JP 2020087514 A JP2020087514 A JP 2020087514A JP 2018214716 A JP2018214716 A JP 2018214716A JP 2018214716 A JP2018214716 A JP 2018214716A JP 2020087514 A JP2020087514 A JP 2020087514A
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battery
battery case
reaction
liquid
cells
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石井　勝
Masaru Ishii
勝 石井
将宏 大石
Masahiro Oishi
将宏 大石
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Toyota Motor Corp
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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

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  • Gas Exhaust Devices For Batteries (AREA)
  • Battery Mounting, Suspending (AREA)

Abstract

To provide a battery pack capable of appropriately suppressing unnecessary electrochemical reaction occurring inside a battery case.SOLUTION: A battery pack includes battery cells (electric cells) 2, an exterior packaging 4, and a reaction suppression liquid 6. The exterior packaging 4 has a bottomed shape, and receives the battery cells 2. The reaction suppression liquid 6 is filled inside the exterior packaging 4. The reaction suppression liquid 6 suppresses electrochemical reaction of the battery cells 2, by flowing into the battery cells 2. The battery cell 2 includes a battery case and a valve part 35. The battery case receives an electrode body and an electrolyte in sealed state. The valve part 35 is provided in the battery case, at a position lower than the liquid level of the reaction suppression liquid 6 filled in the exterior packaging 4, and is opened when the pressure in the battery case rises to a reference level or more.SELECTED DRAWING: Figure 1

Description

本発明は、電解液を備えた電池を備える電池パックに関する。 The present invention relates to a battery pack including a battery including an electrolytic solution.

リチウムイオン二次電池等の二次電池は、軽量で高いエネルギー密度が得られることから、パソコンや携帯端末等のポータブル電源、あるいはＥＶ（電気自動車）、ＨＶ（ハイブリッド自動車）、ＰＨＶ（プラグインハイブリッド自動車）等の車両駆動用電源として広く用いられている。 Rechargeable batteries such as lithium-ion rechargeable batteries are lightweight and have a high energy density, so they are portable power sources such as personal computers and mobile terminals, or EVs (electric vehicles), HVs (hybrid vehicles), PHVs (plug-in hybrids). It is widely used as a power source for driving vehicles such as automobiles.

二次電池の一例として、電極体と電解液を電池ケースに密閉状態で収容した二次電池が知られている。電極体と電解液を備えた二次電池では、各種の電気化学反応（例えば、充電に伴う化学反応等）の影響でガスが発生する場合がある。電極体と電解液が電池ケースの内部に密閉されている場合、内部でガスが発生すると、電池の内圧が上昇する。例えば、特許文献１に記載の二次電池は、電池の内圧が高くなった場合に内部のガスを外部に排出するためのガス排出弁を備える。これにより、電池の内圧が上昇することの抑制を図っている。 As an example of a secondary battery, a secondary battery in which an electrode body and an electrolytic solution are housed in a battery case in a sealed state is known. In a secondary battery including an electrode body and an electrolytic solution, gas may be generated under the influence of various electrochemical reactions (for example, chemical reactions associated with charging). When the electrode body and the electrolytic solution are hermetically sealed inside the battery case, when gas is generated inside, the internal pressure of the battery rises. For example, the secondary battery described in Patent Document 1 includes a gas discharge valve for discharging internal gas to the outside when the internal pressure of the battery becomes high. As a result, the internal pressure of the battery is suppressed from rising.

特開２０１３−５４８２１号公報JP, 2013-54821, A

特許文献１に記載の二次電池では、内圧が上昇した際にガス排出弁によってガスが外部に排出された以後も、ガスを発生させる原因となっていた不要な電気化学反応が継続してしまう場合がある。不要な電気化学反応が継続すると、二次電池に不具合（例えば過度の温度上昇等）が生じることも考えられる。 In the secondary battery described in Patent Document 1, even after the gas is exhausted to the outside by the gas exhaust valve when the internal pressure rises, the unnecessary electrochemical reaction that causes the gas continues. There are cases. If an unnecessary electrochemical reaction continues, a problem (for example, excessive temperature rise) may occur in the secondary battery.

本発明の典型的な目的は、電池ケースの内部で生じる不要な電気化学反応を適切に抑制することが可能な電池パック構造を提供することである。 A typical object of the present invention is to provide a battery pack structure capable of appropriately suppressing unnecessary electrochemical reactions occurring inside the battery case.

かかる目的を実現するべく、ここに開示される一態様の電池パックは、少なくとも１つの電池セル（単電池ともいう）と、該少なくとも１つの電池セルを収容する有底形状の外装体と、該外装体の内部に充填され、前記電池セルの内部に流入することで前記電池セルの電気化学反応を抑制する反応抑制液と、を備え、上記電池セルは、電極体と電解液を密閉状態で内部に収容する電池ケースと、該電池ケースのうち、上記外装体に充填された上記反応抑制液の液面よりも低い位置に設けられ、上記電池ケース内の圧力が基準レベル以上に上昇した場合に開放される弁部と、を備えたことを特徴とする。 In order to achieve such an object, a battery pack according to one aspect disclosed herein includes at least one battery cell (also referred to as a unit cell), a bottomed outer casing that houses the at least one battery cell, and A reaction suppressing liquid that is filled inside the outer package and suppresses an electrochemical reaction of the battery cells by flowing into the battery cells, wherein the battery cells are in a sealed state of the electrode body and the electrolytic solution. A battery case housed inside, and a case where the pressure inside the battery case rises above a reference level provided at a position lower than the liquid level of the reaction suppressing liquid filled in the exterior body in the battery case And a valve portion opened to the.

上記構成の電池パックでは、外装体に収容される電池セル（単電池）の弁部が反応抑制液の液面よりも低い位置に設けられている。従って、電池ケース内の圧力（内圧）が基準レベル以上に上昇して弁部が開放されると、ガスが電池ケースの内部から外部へ排出されると共に、反応抑制液が電池ケースの内部に流入する。その結果、電池セルの内部で発生している不要な電気化学反応が、反応抑制液によって適切に抑制される。 In the battery pack having the above structure, the valve portion of the battery cell (single battery) housed in the exterior body is provided at a position lower than the liquid level of the reaction suppressing liquid. Therefore, when the pressure inside the battery case (internal pressure) rises above the reference level and the valve is opened, the gas is discharged from the inside of the battery case to the outside, and the reaction suppressing liquid flows into the inside of the battery case. To do. As a result, the unnecessary electrochemical reaction occurring inside the battery cell is appropriately suppressed by the reaction suppressing liquid.

電池パック１の概略構成を示す図である。It is a figure which shows schematic structure of the battery pack 1. 電池セル（単電池）２の内部構成を模式的に示す断面図である。It is sectional drawing which shows the internal structure of the battery cell (single battery) 2 typically.

以下、本開示における典型的な実施形態の１つについて、図面を参照しつつ詳細に説明する。本明細書において特に言及している事項以外の事柄であって実施に必要な事柄は、当該分野における従来技術に基づく当業者の設計事項として把握され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。なお、以下の図面においては、同じ作用を奏する部材・部位には同じ符号を付して説明している。また、各図における寸法関係（長さ、幅、厚み等）は実際の寸法関係を反映するものではない。 Hereinafter, one of exemplary embodiments in the present disclosure will be described in detail with reference to the drawings. Matters other than the matters particularly referred to in the present specification and necessary for implementation can be grasped as design matters of a person skilled in the art based on conventional technology in the field. The present invention can be carried out based on the contents disclosed in this specification and the common general technical knowledge in the field. In addition, in the following drawings, the same reference numerals are given to members and parts that have the same effect. Further, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships.

本明細書において、「電池」とは、電気エネルギーを取り出し可能な蓄電デバイス一般を指す用語であって、一次電池および二次電池を含む概念である。「二次電池」とは、繰り返し充放電可能な蓄電デバイス一般をいい、リチウムイオン二次電池、ニッケル水素電池、ニッケルカドミウム電池等のいわゆる蓄電池（すなわち化学電池）の他、電気二重層キャパシタ等のキャパシタ（すなわち物理電池）を包含する。以下、電解液を用いた二次電池の一種である扁平角形のリチウムイオン二次電池を採用した場合を例示して、本開示に係る二次電池について詳細に説明する。ただし、本開示に係る二次電池を、以下の実施形態に記載されたものに限定することを意図したものではない。 In the present specification, the “battery” is a term that generally refers to an electricity storage device that can take out electrical energy, and is a concept that includes a primary battery and a secondary battery. The term “secondary battery” generally refers to a power storage device that can be repeatedly charged and discharged, and includes so-called storage batteries (that is, chemical batteries) such as lithium-ion secondary batteries, nickel-hydrogen batteries, and nickel-cadmium batteries, as well as electric double-layer capacitors and the like. Includes capacitors (ie physical batteries). Hereinafter, the secondary battery according to the present disclosure will be described in detail by exemplifying a case where a flat prismatic lithium-ion secondary battery that is a type of secondary battery using an electrolytic solution is adopted. However, the secondary battery according to the present disclosure is not intended to be limited to those described in the following embodiments.

図１を参照して、本実施形態の電池パック１の構成について説明する。電池パック１は、電池セル（単電池）２、外装体４、および反応抑制液６を備える。詳細は後述するが、電池セル２は、電極体２０および電解液１０（図２参照）を内部に備え、単体で二次電池として機能する電池である。一例として、本実施形態では、互いに電気的に接続された複数の電池セル２を備える電池パック１（組電池）を例示して説明を行う。ただし、本開示で例示する技術の少なくとも一部は、電池セルを１つ備えた電池パックにも適用できる。一例として、本実施形態の電池パック１は、互いに電気的に接続された１０個の電池セル２を備える。しかし、電池パック１を組電池とする場合、電池セル２の数を適宜変更できることは言うまでもない。 The configuration of the battery pack 1 of the present embodiment will be described with reference to FIG. The battery pack 1 includes a battery cell (unit cell) 2, an outer casing 4, and a reaction suppressing liquid 6. As will be described in detail later, the battery cell 2 is a battery that includes the electrode body 20 and the electrolytic solution 10 (see FIG. 2) inside and functions as a secondary battery by itself. As an example, in the present embodiment, a battery pack 1 (assembled battery) including a plurality of battery cells 2 electrically connected to each other will be described as an example. However, at least part of the technology exemplified in the present disclosure can be applied to a battery pack including one battery cell. As an example, the battery pack 1 of this embodiment includes 10 battery cells 2 electrically connected to each other. However, it goes without saying that when the battery pack 1 is used as an assembled battery, the number of battery cells 2 can be changed as appropriate.

外装体４は、電池セル２（本実施形態では複数の電池セル２）と反応抑制液６を内部に収容する有底形状（本実施形態では有底箱状）に形成されている。外装体４の形状は、収容されている電池セル２および反応抑制液６の全周を覆う形状であってもよいし、一部（例えば上面）が開放された形状であってもよい。外装体４の材質には、充填された反応抑制液６を保持することが可能な各種材質のいずれかを適宜選択できる。例えば、外装体４の材質として、金属または樹脂が採用されてもよい。外装体４は、剛性を有していてもよいし、適度な可撓性を有していてもよい。なお、図１では、電池パック１の構成の理解を容易にするために、外装体４の材質を透明とした状態で各構成が図示されている。しかし、外装体４の材質は透明である必要は無い。 The outer casing 4 is formed in a bottomed shape (bottomed box shape in the present embodiment) that accommodates the battery cells 2 (the plurality of battery cells 2 in the present embodiment) and the reaction suppressing liquid 6 inside. The shape of the outer package 4 may be a shape that covers the entire circumferences of the battery cells 2 and the reaction suppressing liquid 6 that are contained, or may be a shape that a part (for example, the upper surface) is open. As the material of the outer package 4, any of various materials capable of holding the filled reaction suppressing liquid 6 can be appropriately selected. For example, metal or resin may be adopted as the material of the outer package 4. The exterior body 4 may have rigidity or may have appropriate flexibility. In addition, in FIG. 1, in order to facilitate understanding of the configuration of the battery pack 1, each configuration is illustrated in a state where the material of the exterior body 4 is transparent. However, the material of the outer package 4 need not be transparent.

反応抑制液６は、有底形状の外装体４の内部に充填されている。つまり、反応抑制液６は、電池セル２の少なくとも底部の外周を覆っている。反応抑制液６は、電池セル２の内部に流入した際に、電池セル２の内部で生じるガスの発生反応を抑制する。ガスの発生反応とは、ガスと発生させる原因となる不要な電気化学反応を言う。例えば、電池セル２の一部の不具合等の影響で、電極における電気化学反応が活性化された状態となり、不要なガスを発生させる場合があり得る。この場合、反応抑制液６は、電気化学反応の活性状態を抑制することで、ガスの発生反応を抑制する。一例として、本実施形態の反応抑制液６は、電池セル２の内部に流入して短絡を発生させて放電させることで、電池電圧を低下させて（例えば０Ｖ近くまで低下させて電池を失活させ得る。）ガスの発生反応を抑制する。反応抑制液６の材質には、電気化学反応を抑制することが可能な種々の材質を採用することができる。例えば、凝固点が低く、且つ融点が高いエチレングリコールを主成分とするクーラント等の液状冷却材を、反応抑制液６として使用することができる。また、水等が反応抑制液６として使用されてもよい。 The reaction suppressing liquid 6 is filled inside the bottomed outer casing 4. That is, the reaction suppressing liquid 6 covers at least the outer periphery of the bottom of the battery cell 2. The reaction suppressing liquid 6 suppresses the gas generation reaction that occurs inside the battery cells 2 when flowing into the battery cells 2. The gas generation reaction is an unnecessary electrochemical reaction that causes gas to be generated. For example, the electrochemical reaction in the electrodes may be activated due to the influence of a part of the battery cell 2 or the like, and unnecessary gas may be generated. In this case, the reaction suppressing liquid 6 suppresses the gas generation reaction by suppressing the active state of the electrochemical reaction. As an example, the reaction suppressing liquid 6 of the present embodiment flows into the inside of the battery cell 2 to cause a short circuit and discharge, thereby lowering the battery voltage (for example, lowering it to near 0 V to deactivate the battery). The gas generation reaction is suppressed. As the material of the reaction suppressing liquid 6, various materials capable of suppressing the electrochemical reaction can be adopted. For example, a liquid coolant such as a coolant whose main component is ethylene glycol having a low freezing point and a high melting point can be used as the reaction suppressing liquid 6. Further, water or the like may be used as the reaction suppressing liquid 6.

図２を参照して、電池セル２について説明する。本実施形態に係る電池セル２は、電極体２０、電解液１０、および電池ケース３０を備えた密閉型のリチウムイオン二次電池である。ただし、電池セル２として、リチウムイオン二次電池以外の二次電池（例えばニッケル水素二次電池等）が採用されてもよい。 The battery cell 2 will be described with reference to FIG. The battery cell 2 according to this embodiment is a sealed lithium-ion secondary battery including the electrode body 20, the electrolytic solution 10, and the battery case 30. However, as the battery cell 2, a secondary battery (for example, a nickel-hydrogen secondary battery) other than the lithium-ion secondary battery may be adopted.

電池ケース３０は、電極体２０および電解液１０を内部に密閉した状態で収容する。本実施形態における電池ケース３０の形状は、扁平な角形である。電池ケース３０は、一端（本実施形態では上端）に開口部を有する箱型の本体３１と、該本体の開口部を塞ぐ板状の蓋体３２を備える。電池ケース３０（詳細には、電池ケース３０の蓋体３２）には、外部接続用の正極端子４２および負極端子４４が設けられている。また、電池ケース３０には、電解液１０を内部に注入するための注入口（図示せず）が設けられている。電池ケース３０の材質としては、例えば、アルミニウム等の軽量で熱伝導性の良い金属材料等を使用することができる。また、電池ケース３０の形状は、角形以外の形状（例えば円筒状等）であってもよい。 The battery case 30 accommodates the electrode body 20 and the electrolytic solution 10 in a sealed state. The shape of the battery case 30 in this embodiment is a flat rectangular shape. The battery case 30 includes a box-shaped main body 31 having an opening at one end (upper end in the present embodiment), and a plate-shaped lid 32 that closes the opening of the main body. The battery case 30 (specifically, the lid 32 of the battery case 30) is provided with a positive electrode terminal 42 and a negative electrode terminal 44 for external connection. Further, the battery case 30 is provided with an injection port (not shown) for injecting the electrolytic solution 10 therein. As a material of the battery case 30, for example, a lightweight and highly heat-conductive metal material such as aluminum can be used. In addition, the shape of the battery case 30 may be a shape other than a square shape (for example, a cylindrical shape).

電池ケース３０は、弁部３５を備える。弁部３５は、電池ケース３０内の圧力が基準レベル以上に上昇した場合に開放される。弁部３５が設けられる位置、および弁部３５の機能の詳細については後述する。 The battery case 30 includes a valve portion 35. The valve portion 35 is opened when the pressure inside the battery case 30 rises above a reference level. The position where the valve portion 35 is provided and details of the function of the valve portion 35 will be described later.

電池ケース３０の外周部には、電気絶縁性を有する絶縁部３８が設けられている。絶縁部３８は、電池ケース３０のうち、少なくとも反応抑制液６（図１参照）の液面Ｈから下方の部分の外周面の全体を覆う。従って、電池ケース３０と反応抑制液６を介した電池セル２間の短絡が、絶縁部３８によって抑制される。 An insulating portion 38 having electrical insulation is provided on the outer peripheral portion of the battery case 30. The insulating portion 38 covers at least the entire outer peripheral surface of the battery case 30 at least below the liquid level H of the reaction suppressing liquid 6 (see FIG. 1 ). Therefore, a short circuit between the battery case 30 and the battery cell 2 via the reaction suppressing liquid 6 is suppressed by the insulating portion 38.

絶縁部３８の具体的な構成は、適宜選択できる。一例として、本実施形態では、絶縁性を有する材質（例えば、ポリプロピレン、ポリエチレン等の樹脂材料等）によって形成された絶縁フィルムによって、電池ケース３０の底面および側面の全体が覆われることで、絶縁部３８が形成されている。この場合、絶縁部３８のうち少なくとも弁部３５に対向する位置が、弁部３５が開放されることで破断されるように、絶縁部３８および弁部３５の少なくとも一方が形成されていてもよい。例えば、弁部３５は、開放時に一部を外側に突出させて絶縁部３８を破断してもよい。その結果、弁部３５が開放されることで、反応抑制液６が弁部３５に到達する。また、絶縁部３８と電池ケース３０の外周面の間に反応抑制液６が充填されていてもよい。この場合、絶縁部３８は、内側と外側の間で反応抑制液６の移動を禁止することで、電池セル２間の短絡を防止してもよい。また、弁部３５を含む電池ケース３０の少なくとも外周面が、絶縁性を有する材質によって形成されることで、絶縁部３８が形成されていてもよい。また、電池パック１が、１つの電池セル２のみ備えた場合には、絶縁部３８は省略されてもよい。 The specific configuration of the insulating portion 38 can be appropriately selected. As an example, in the present embodiment, the entire bottom surface and side surfaces of the battery case 30 are covered with an insulating film formed of an insulating material (for example, a resin material such as polypropylene or polyethylene), so that the insulating portion is covered. 38 is formed. In this case, at least one of the insulating portion 38 and the valve portion 35 may be formed such that at least a position of the insulating portion 38 facing the valve portion 35 is broken by opening the valve portion 35. .. For example, the valve portion 35 may project a part outward when the valve portion 35 is opened to break the insulating portion 38. As a result, the reaction suppressing liquid 6 reaches the valve portion 35 by opening the valve portion 35. Further, the reaction suppressing liquid 6 may be filled between the insulating portion 38 and the outer peripheral surface of the battery case 30. In this case, the insulating unit 38 may prevent the short circuit between the battery cells 2 by prohibiting the movement of the reaction suppressing liquid 6 between the inside and the outside. In addition, the insulating portion 38 may be formed by forming at least the outer peripheral surface of the battery case 30 including the valve portion 35 with a material having an insulating property. Further, when the battery pack 1 includes only one battery cell 2, the insulating portion 38 may be omitted.

本実施形態の電極体２０には、長尺状の正極体（正極シート）５０、長尺状の負極体（負極シート）６０、および、２枚の長尺状のセパレータ（セパレータシート）７０が重ね合わされて長手方向に捲回された捲回電極体が採用されている。詳細には、正極体５０では、長尺状の正極集電体５２の片面または両面（本実施形態では両面）に、長手方向に沿って正極活物質層５４が形成されている。負極体６０では、長尺状の負極集電体６２の片面または両面（本実施形態では両面）に、長手方向に沿って負極活物質層６４が形成されている。なお、電極体２０の捲回軸方向（上記長手方向に直交するシート幅方向）の両側から外方にはみ出すように形成された、正極活物質層非形成部分５２Ａ（即ち、正極活物質層５４が形成されずに正極集電体５２が露出した部分）と、負極活物質層非形成部分６２Ａ（即ち、負極活物質層６４が形成されずに負極集電体６２が露出した部分）には、それぞれ、正極集電板４２Ａおよび負極集電板４４Ａが接合されている。正極集電板４２Ａには正極端子４２が電気的に接続され、負極集電板４４Ａには負極端子４４が電気的に接続されている。なお、電極体の構成を変更することも可能である。例えば、捲回電極体の代わりに積層型の電極体が用いられてもよい。 The electrode body 20 of the present embodiment includes a long positive electrode body (positive electrode sheet) 50, a long negative electrode body (negative electrode sheet) 60, and two long separators (separator sheet) 70. A wound electrode body is used which is superposed and wound in the longitudinal direction. Specifically, in the positive electrode body 50, the positive electrode active material layer 54 is formed along the longitudinal direction on one surface or both surfaces (both surfaces in the present embodiment) of the elongated positive electrode current collector 52. In the negative electrode body 60, the negative electrode active material layer 64 is formed along the longitudinal direction on one surface or both surfaces (both surfaces in the present embodiment) of the elongated negative electrode current collector 62. The positive electrode active material layer-free portion 52A (that is, the positive electrode active material layer 54) is formed so as to extend outward from both sides of the electrode body 20 in the winding axis direction (the sheet width direction orthogonal to the longitudinal direction). Is not formed and the positive electrode current collector 52 is exposed) and the negative electrode active material layer non-formed portion 62A (that is, the negative electrode current collector 62 is exposed without the negative electrode active material layer 64 being formed). The positive electrode current collector plate 42A and the negative electrode current collector plate 44A are joined to each other. The positive electrode terminal 42 is electrically connected to the positive electrode collector plate 42A, and the negative electrode terminal 44 is electrically connected to the negative electrode collector plate 44A. It is also possible to change the configuration of the electrode body. For example, a laminated electrode body may be used instead of the wound electrode body.

電極体２０の正負極を構成する材料、部材は、従来の一般的な二次電池に用いられるものと同様のものを制限なく使用可能である。例えば、正極集電体５２には、良好な導電性を有する金属材（アルミニウム、ニッケル、チタン、またはステンレス鋼等）を採用できる。正極活物質層５４の正極活物質としては、例えば層状構造やスピネル構造等のリチウム複合金属酸化物（例えば、ＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２、ＬｉＮｉＯ２、ＬｉＣｏＯ２、ＬｉＦｅＯ２、ＬｉＭｎ２Ｏ４、ＬｉＮｉ０．５Ｍｎ１．５Ｏ４，ＬｉＣｒＭｎＯ４、ＬｉＦｅＰＯ４等）が挙げられる。また、負極集電体６２には、良好な導電性を有する金属材（銅、または銅を主体とする合金等）を採用できる。負極活物質層６４の負極活物質としては、例えば、少なくとも一部にグラファイト構造（層状構造）を含む粒子状（或いは球状、鱗片状）の炭素材料、リチウム遷移金属複合酸化物（例えば、Ｌｉ４Ｔｉ５Ｏ１２等のリチウムチタン複合酸化物）、リチウム遷移金属複合窒化物等が挙げられる。セパレータ７０としては、従来公知の多孔質シートからなるセパレータを特に制限なく使用することができる。例えば、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）等のポリオレフィン樹脂から成る多孔質シート（フィルム、不織布等）が挙げられる。 The materials and members forming the positive and negative electrodes of the electrode body 20 can be the same as those used in conventional general secondary batteries without limitation. For example, the positive electrode current collector 52 can be made of a metal material having good conductivity (aluminum, nickel, titanium, stainless steel, or the like). As the positive electrode active material of the positive electrode active material layer 54, for example, a lithium composite metal oxide having a layered structure or a spinel structure (for example, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , LiNiO 2 , LiCoO 2 , LiFeO 2) is used . 2 , LiMn 2 O 4 , LiNi 0.5 Mn 1.5 O 4 , LiCrMnO 4 , LiFePO 4 and the like). Further, for the negative electrode current collector 62, a metal material having good conductivity (copper, an alloy mainly containing copper, or the like) can be adopted. As the negative electrode active material of the negative electrode active material layer 64, for example, a particulate (or spherical or scale-like) carbon material containing a graphite structure (layered structure) at least in part, a lithium transition metal composite oxide (for example, Li 4 Examples thereof include lithium titanium composite oxides such as Ti 5 O 12 ) and lithium transition metal composite nitrides. As the separator 70, a conventionally known separator made of a porous sheet can be used without particular limitation. For example, a porous sheet (film, nonwoven fabric, etc.) made of a polyolefin resin such as polyethylene (PE) or polypropylene (PP) can be used.

電極体２０とともに電池ケース３０に収容される電解液１０は、典型的には溶媒と支持塩を含む。溶媒としては、例えば、エチレンカーボネート（ＥＣ）、ジエチルカーボネート（ＤＥＣ）、ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）等の非水溶媒を用いることができる。支持塩としては、例えば、リチウム塩、ナトリウム塩、マグネシウム塩等を用いることができる。 The electrolytic solution 10 housed in the battery case 30 together with the electrode body 20 typically contains a solvent and a supporting salt. As the solvent, for example, a nonaqueous solvent such as ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC) can be used. As the supporting salt, for example, lithium salt, sodium salt, magnesium salt and the like can be used.

図１および図２を参照して、電池ケース３０が備える弁部３５について詳細に説明する。弁部３５は、電池ケース３０のうち、外装体４に充填された反応抑制液６の液面の高さＨよりも低い位置に設けられている。換言すると、外装体４に充填される反応抑制液６の量は、電池ケース３０の弁部３５を浸す量以上の量とされる。 The valve unit 35 included in the battery case 30 will be described in detail with reference to FIGS. 1 and 2. The valve portion 35 is provided in the battery case 30 at a position lower than the height H of the liquid surface of the reaction suppressing liquid 6 with which the exterior body 4 is filled. In other words, the amount of the reaction suppressing liquid 6 with which the exterior body 4 is filled is set to be equal to or larger than the amount by which the valve portion 35 of the battery case 30 is dipped.

本実施形態では、扁平な角形の電池ケース３０の４つの側面のうち、他の電池セル２の電池ケース３０と対向しない２つの側面の各々に設けられている。従って、弁部３５が開放された場合に、反応抑制液６が適切に弁部３５から電池ケース３０の内部に流入する。しかし、弁部３５の位置および数の少なくとも一方を変更することも可能である。例えば、弁部３５は、他の電池セル２の電池ケース３０と対向しない２つの側面の一方にのみ設けられていてもよい。また、電池ケース３０の底面も反応抑制液６に接触している場合には、電池ケース３０の底面に弁部３５が設けられていてもよい。 In the present embodiment, among the four side surfaces of the flat prismatic battery case 30, the two side surfaces that do not face the battery cases 30 of the other battery cells 2 are provided. Therefore, when the valve portion 35 is opened, the reaction suppressing liquid 6 appropriately flows into the battery case 30 from the valve portion 35. However, it is possible to change at least one of the position and the number of the valve portions 35. For example, the valve portion 35 may be provided only on one of the two side surfaces that do not face the battery case 30 of the other battery cell 2. Further, when the bottom surface of the battery case 30 is also in contact with the reaction suppressing liquid 6, the valve portion 35 may be provided on the bottom surface of the battery case 30.

前述したように、弁部３５は、電池ケース３０内の圧力が基準レベル以上に上昇した場合に開放される。弁部３５が開放されると、電池ケース３０内で発生したガスが、弁部３５を通じて外部へ排出される。その結果、電池ケース３０の内圧の上昇が抑制される。また、弁部３５は反応抑制液６の液面の高さＨよりも低い位置に設けられているので、弁部３５が開放されると、反応抑制液６が弁部３５を通じて内部へ流入する。その結果、電池セル２の内部で発生している不要な電気化学反応（例えばガスの発生反応）が、反応抑制液６によって適切に抑制される。従って、不要な電気化学反応が継続することで生じる不具合が、適切に抑制される。 As described above, the valve portion 35 is opened when the pressure inside the battery case 30 rises above the reference level. When the valve portion 35 is opened, the gas generated in the battery case 30 is discharged to the outside through the valve portion 35. As a result, the rise in internal pressure of the battery case 30 is suppressed. Further, since the valve portion 35 is provided at a position lower than the height H of the liquid surface of the reaction suppressing liquid 6, when the valve portion 35 is opened, the reaction suppressing liquid 6 flows into the inside through the valve portion 35. . As a result, the unnecessary electrochemical reaction (for example, gas generation reaction) occurring inside the battery cell 2 is appropriately suppressed by the reaction suppressing liquid 6. Therefore, a defect caused by continuing an unnecessary electrochemical reaction is appropriately suppressed.

１ 電池パック
２ 電池セル
４ 外装体
６ 反応抑制液
１０ 電解液
２０ 電極体
３０ 電池ケース
３５ 弁部

1 Battery Pack 2 Battery Cell 4 Outer Body 6 Reaction Suppressing Liquid 10 Electrolyte 20 Electrode Body 30 Battery Case 35 Valve Section

Claims (1)

少なくとも１つの電池セルと、
前記少なくとも１つの電池セルを収容する有底形状の外装体と、
前記外装体の内部に充填され、前記電池セルの内部に流入することで前記電池セルの電気化学反応を抑制する反応抑制液と、
を備え、
前記電池セルは、
電極体と電解液を密閉状態で内部に収容する電池ケースと、
前記電池ケースのうち、前記外装体に充填された前記反応抑制液の液面よりも低い位置に設けられ、前記電池ケース内の圧力が基準レベル以上に上昇した場合に開放される弁部と、
を備えたことを特徴とする電池パック。


At least one battery cell,
A bottomed outer casing that houses the at least one battery cell;
A reaction suppressing liquid that is filled inside the outer package and suppresses an electrochemical reaction of the battery cells by flowing into the battery cells,
Equipped with
The battery cell is
A battery case in which the electrode body and the electrolytic solution are housed in a sealed state,
Of the battery case, a valve portion provided at a position lower than the liquid level of the reaction suppressing liquid filled in the exterior body, and opened when the pressure in the battery case rises to a reference level or higher,
A battery pack comprising:


JP2018214716A 2018-11-15 2018-11-15 Battery pack Pending JP2020087514A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010015953A (en) * 2008-07-07 2010-01-21 Toyota Motor Corp Energy storage device and vehicle
JP2010061989A (en) * 2008-09-03 2010-03-18 Toyota Motor Corp Storage battery device
JP2010177018A (en) * 2009-01-29 2010-08-12 Toyota Motor Corp Power storage device
JP2013149459A (en) * 2012-01-19 2013-08-01 Gs Yuasa Corp Power storage module
JP2018125109A (en) * 2017-01-31 2018-08-09 日立オートモティブシステムズ株式会社 Secondary battery and battery pack

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010015953A (en) * 2008-07-07 2010-01-21 Toyota Motor Corp Energy storage device and vehicle
JP2010061989A (en) * 2008-09-03 2010-03-18 Toyota Motor Corp Storage battery device
JP2010177018A (en) * 2009-01-29 2010-08-12 Toyota Motor Corp Power storage device
JP2013149459A (en) * 2012-01-19 2013-08-01 Gs Yuasa Corp Power storage module
JP2018125109A (en) * 2017-01-31 2018-08-09 日立オートモティブシステムズ株式会社 Secondary battery and battery pack

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