JPH08273649A - Sealed battery - Google Patents

Sealed battery

Info

Publication number
JPH08273649A
JPH08273649A JP7078711A JP7871195A JPH08273649A JP H08273649 A JPH08273649 A JP H08273649A JP 7078711 A JP7078711 A JP 7078711A JP 7871195 A JP7871195 A JP 7871195A JP H08273649 A JPH08273649 A JP H08273649A
Authority
JP
Japan
Prior art keywords
battery
valve body
safety valve
valve device
elastic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP7078711A
Other languages
Japanese (ja)
Other versions
JP3158946B2 (en
Inventor
Jiro Onagawa
治郎 小名川
Norio Suzuki
憲男 鈴木
Ryuji Akimoto
隆二 秋元
Mitsuru Namihana
満 浪花
Toshihisa Hiroshima
敏久 広島
Yasuhiro Takeuchi
康弘 竹内
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP07871195A priority Critical patent/JP3158946B2/en
Publication of JPH08273649A publication Critical patent/JPH08273649A/en
Application granted granted Critical
Publication of JP3158946B2 publication Critical patent/JP3158946B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30Arrangements for facilitating escape of gases
    • H01M50/317Re-sealable arrangements
    • H01M50/325Re-sealable arrangements comprising deformable valve members, e.g. elastic or flexible valve members
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Gas Exhaust Devices For Batteries (AREA)

Abstract

PURPOSE: To provide the highly safe battery whose valve actuating pressure can be stably maintained over a long period of time by specifying an elastic valve body of a safety valve device in the battery having a battery vessel to house a power generating element and the safety valve device having the prescribed constitution. CONSTITUTION: In the battery, a battery vessel 1 to house a power generating element and a safety valve device to seal an opening part of the battery vessel 1 are provided, and the safety valve device is composed of a disk-shaped sealing plate 2 having a gas ventilating hole 2a in a central part, an elastic valve body 7 which is arranged on the sealing plate 2 and blocks up the gas ventilating hole 2a and a cap-shaped positive electrode terminal 5 where the valve body 7 is positioned in a valve chamber 7. The elastic valve body 7 of the safety valve device in this battery is formed by cross-linking ethylene propylene rubber by mixing thermoplastic elastomer and ethylene propylene rubber together.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、電池の安全性を高める
ための安全弁装置を有する密閉型電池に関するものであ
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery having a safety valve device for enhancing battery safety.

【0002】[0002]

【従来の技術】近年、各種携帯機器の普及に伴い電池、
特に再充電が可能な二次電池が広い分野で利用されてい
る。これら機器に使用される電池として、従来より鉛蓄
電池、ニッケル・カドミウム蓄電池が用いられてきた
が、新たにニッケル・水素蓄電池やリチウムイオン二次
電池などが加わってきた。
2. Description of the Related Art Recently, with the spread of various portable devices, batteries,
In particular, rechargeable secondary batteries are widely used. Lead-acid batteries and nickel-cadmium batteries have been used as batteries for these devices, but nickel-hydrogen batteries and lithium-ion secondary batteries have been newly added.

【0003】これらの再充電可能な電池の中で、鉛蓄電
池、ニッケル・カドミウム蓄電池、ニッケル・水素蓄電
池等の水溶液を電解液としている電池では、所謂、ノイ
マン方式により電池内部で発生するガスを消費すること
により密閉化を可能にしている。
Among these rechargeable batteries, a battery using an aqueous solution as an electrolyte such as a lead storage battery, a nickel-cadmium storage battery, a nickel-hydrogen storage battery consumes gas generated inside the battery by a so-called Neumann method. By doing so, sealing is possible.

【0004】一方、リチウムイオン二次電池など非水電
解液を用いた電池では、過充電や過放電を避けることで
密閉化を図ってきた。
On the other hand, a battery using a non-aqueous electrolyte such as a lithium ion secondary battery has been hermetically sealed by avoiding overcharge and overdischarge.

【0005】しかし、充電器の故障や、電池の誤使用、
外部短絡などに起因した異常事態に陥った時、電池の内
圧が上昇し、破裂に至ることがある。この電池の破裂を
防止するために、二次電池は、内圧が予め設定された値
を越えた場合に、電池内部に発生したガスが外部に放出
されるように安全弁装置を備えている。
However, due to a failure of the charger, misuse of the battery,
When an abnormal situation such as an external short circuit occurs, the internal pressure of the battery rises, which may lead to rupture. In order to prevent the battery from bursting, the secondary battery is equipped with a safety valve device so that the gas generated inside the battery is released to the outside when the internal pressure exceeds a preset value.

【0006】以下、安全弁装置を有する密閉型電池につ
いて説明する。図3は密閉型電池の上部縦断面図であ
る。この図3において、電池容器である金属製ケース1
は、ケース1の上部に絶縁性と気密性の保持の役割を果
たすガスケット3を介して、中央部にガス通気孔2aを
形成した金属製の封口板2を、カシメ加工により装着固
定している。上記ケース1の内部には、詳細な図示は行
っていないが、セパレータを介して正極板と負極板とを
重ね合わせ、渦巻状に捲回した極板群とアルカリ電解液
からなる発電要素4が収納されている。さらに、封口板
2には、安全弁装置を構成するためにも用いられるキャ
ップ状の正極端子5が設けられている。この正極端子5
は、キャップ状をなしており、その一部にガス排気口5
aや孔が形成されている。正極端子5と封口板2とに囲
まれた空間には、弁室6が形成されており、この弁室6
内に弾性弁体7を圧縮した状態で内蔵している。この弾
性弁体7の機構としては、金属バネやゴムの弾性を利用
したものが一般的である。
Hereinafter, a sealed battery having a safety valve device will be described. FIG. 3 is a vertical cross-sectional view of the top of the sealed battery. In FIG. 3, a metal case 1 which is a battery container
In the case 1, a metal sealing plate 2 having a gas vent hole 2a formed in the central portion is mounted and fixed by caulking on the upper part of a case 1 through a gasket 3 which plays a role of maintaining insulation and airtightness. . Although not shown in detail in the inside of the case 1, there is provided a power generation element 4 including a positive electrode plate and a negative electrode plate which are superposed with a separator interposed therebetween, and a spirally wound electrode plate group and an alkaline electrolyte. It is stored. Further, the sealing plate 2 is provided with a cap-shaped positive electrode terminal 5 which is also used to form a safety valve device. This positive terminal 5
Has a cap shape, and the gas exhaust port 5
a and holes are formed. A valve chamber 6 is formed in the space surrounded by the positive electrode terminal 5 and the sealing plate 2.
The elastic valve body 7 is incorporated therein in a compressed state. As a mechanism of the elastic valve body 7, a mechanism utilizing the elasticity of a metal spring or rubber is generally used.

【0007】以上のような構成を有する密閉型電池にお
いて、充電器の故障による過大な充電電流の流入や、転
極を伴うような過放電などに起因する電池の内圧上昇が
生じた場合、高圧状態となったガスは、弾性弁体を押し
上げ、正極端子5のガス排気口5aから排出される。
In the sealed battery having the above-mentioned structure, if the internal pressure of the battery rises due to excessive inflow of charging current due to failure of the charger or over-discharging accompanied by reversal of polarity, The gas in this state pushes up the elastic valve body and is discharged from the gas exhaust port 5a of the positive electrode terminal 5.

【0008】通常用いられている上記安全弁装置は、電
池の内圧が10kg/cm2以上に達したときに、ガス
が外部に放出されるように設定されている。従って、急
激なガス発生を伴わない程度の過充電が行われた場合、
負極のガス吸収能力が低下するにつれ、内圧は上昇す
る。この時、電池内部のガスが外部に放出されても問題
なく、充電が停止され、電池の内圧が下がれば、安全弁
装置は元の形に戻り、再び使用可能になるようにしてい
る。また、急速充電を可能にするためには安全弁の定格
許容圧力を20kg/cm2程度まで高めることもあ
る。
The normally used safety valve device is set so that gas is released to the outside when the internal pressure of the battery reaches 10 kg / cm 2 or more. Therefore, when overcharging is performed to the extent that sudden gas generation is not involved,
The internal pressure increases as the gas absorption capacity of the negative electrode decreases. At this time, even if the gas inside the battery is released to the outside, there is no problem, and if the charging is stopped and the internal pressure of the battery drops, the safety valve device returns to its original shape and becomes usable again. Further, the rated allowable pressure of the safety valve may be increased to about 20 kg / cm 2 in order to enable rapid charging.

【0009】[0009]

【発明が解決しようとする課題】弾性体の硬度を高めた
り、あるいは圧縮率を大きくすることによって、弾性体
の変形率を小さくし、内圧の許容値を高めているが、設
定値以上の電流が電池に流れ込み、ガスの異常発生が生
じたときには、このような弾性体を用いた安全弁装置で
は、ガス排気口からの排出速度が電池内部でのガスの発
生速度に追いつけない。そのため、電池内圧が急激に上
昇し、破裂に至る可能性を有している。また、電池内部
の温度上昇により、弾性ゴム弁体が弁室一杯に熱膨脹
し、本来の弁体動作機能が維持できなくなり、上記同様
に電池内圧が上昇し、破裂に至ることも考えられる。
By increasing the hardness of the elastic body or increasing the compression rate, the deformation rate of the elastic body is reduced and the allowable value of the internal pressure is increased. When gas flows into the battery and an abnormal gas is generated, the safety valve device using such an elastic body cannot keep up with the gas generation speed inside the battery in the discharge speed from the gas exhaust port. Therefore, there is a possibility that the internal pressure of the battery rises sharply and the battery bursts. It is also conceivable that due to the temperature rise inside the battery, the elastic rubber valve body thermally expands to fill the valve chamber and the original valve body operating function cannot be maintained, and the internal pressure of the battery rises in the same manner as above, leading to rupture.

【0010】特開平5−41204号公報では、火中に
電池を投じた際の安全性を確保するために、パッキング
材もしくは安全弁体のうちの少なくとも一方の融点を2
70℃以下にすることが記載されている。しかし、過大
な電流が電池に印加され、電池温度が100℃程度に達
すると負極に吸蔵されている水素が放出され始め、電池
の内圧は急激に上昇し、破裂に到る。上記公報に記載さ
れた構成では、このような過大な電流の流れ込みに起因
した破裂には、対応できない可能性がある。
In Japanese Laid-Open Patent Publication No. 5-41204, at least one of the packing material and the safety valve body has a melting point of 2 in order to ensure safety when a battery is thrown into a fire.
It is described that the temperature is 70 ° C. or lower. However, when an excessive current is applied to the battery and the battery temperature reaches about 100 ° C., hydrogen stored in the negative electrode starts to be released, the internal pressure of the battery rises rapidly, and the battery bursts. The configuration described in the above publication may not be able to cope with a burst caused by such an excessive current flow.

【0011】さらに同公報には、弾性弁体にオレフィン
系熱可塑性エラストマーを用いる点についての開示もな
されている。電池温度が上昇した場合に、熱可塑性エラ
ストマーの軟化や溶解により弁作動圧力が低下し過ぎ、
実質的にガス通気孔が開放状態となる。その結果、外気
が電池内に流入し、負極の水素吸蔵合金との酸化反応を
促進し、電池が着火する可能性がある。
Further, the publication also discloses that an olefinic thermoplastic elastomer is used for the elastic valve body. When the battery temperature rises, the valve operating pressure drops too much due to softening and melting of the thermoplastic elastomer,
The gas vent is substantially open. As a result, outside air may flow into the battery, accelerate the oxidation reaction with the hydrogen storage alloy of the negative electrode, and the battery may ignite.

【0012】また、エチレンプロピレンゴムを主成分と
する弾性ゴム弁体は、主に酸化によって次第にゴム弾性
を失っていく。このゴム弾性の経時変化により、安全弁
装置の弁作動圧力は低下するため、電解液の漏出抑止な
ど長期信頼性を確保するための弁作動圧力の設定が困難
であった。
An elastic rubber valve body containing ethylene propylene rubber as a main component gradually loses rubber elasticity mainly due to oxidation. Since the valve operating pressure of the safety valve device is lowered due to the change of rubber elasticity with time, it is difficult to set the valve operating pressure for ensuring long-term reliability such as prevention of leakage of electrolyte.

【0013】本発明は、弁作動圧力を長期間に渡って安
定維持できる信頼性を確保し、また電池の急激な温度上
昇に伴う内圧の変化により生じる安全性の問題を解消で
きる安全弁装置を有する密閉型電池を提供することを目
的としている。
The present invention has a safety valve device which can ensure the reliability that the valve operating pressure can be stably maintained for a long period of time and can solve the safety problem caused by the change of the internal pressure due to the rapid temperature rise of the battery. It is intended to provide a sealed battery.

【0014】[0014]

【課題を解決するための手段】上記目的を達成するため
に本発明の密閉型電池は、安全弁装置に内蔵される弾性
弁体に、熱可塑性エラストマー(以下、TPEとする)
とエチレンプロピレンゴム(以下、EPDMとする)と
を混合し、前記EPDMを架橋形成したものを用い、1
00〜120℃における安全弁装置の弁作動圧力を4〜
8kg/cm2に設定し、この弁作動圧力を250℃ま
で保持させたものである。
In order to achieve the above object, the sealed battery of the present invention comprises a thermoplastic elastomer (hereinafter referred to as TPE) in an elastic valve body incorporated in a safety valve device.
And ethylene propylene rubber (hereinafter referred to as EPDM) are mixed, and EPDM is crosslinked to form 1
The valve operating pressure of the safety valve device at 0 to 120 ° C is 4 to
It was set to 8 kg / cm 2 and the valve operating pressure was kept up to 250 ° C.

【0015】[0015]

【作用】TPEは熱可塑性を付与する硬質相と、弾性を
付与する軟質相との2相から構成されている。設定値以
上の大電流が流れ、これにより電池温度が上昇し、ガス
の異常発生が生じた場合に、このTPEを形成している
硬質相が溶けることにより、弾性弁体としての作動圧力
が低下し、実質的にガス排気口からの排出速度が大きく
なる。排出速度が内部ガス発生速度に追従することで電
池内圧の上昇を抑え、電池の破裂を防止できる。
The TPE is composed of two phases, a hard phase that imparts thermoplasticity and a soft phase that imparts elasticity. When a large current exceeding the set value flows and the battery temperature rises due to this, and the gas abnormally occurs, the hard phase forming this TPE is melted, and the operating pressure as the elastic valve decreases. However, the discharge rate from the gas outlet is substantially increased. Since the discharge speed follows the internal gas generation speed, it is possible to prevent the battery internal pressure from rising and prevent the battery from bursting.

【0016】また、EPDMはTPEと混合後、それ自
身を架橋しているので高温時にTPEが軟化してもEP
DMの架橋構造は維持されるため、弁作動圧力の過度の
低下が防止され、外気が電池内に流入することはない。
これにより、特にニッケル・水素蓄電池やリチウム電池
など、外部からの空気や酸素の流入に起因する発火を防
止できる。
Also, since EPDM is cross-linked with TPE after mixing with TPE, even if TPE softens at high temperatures, EPDM
Since the cross-linked structure of DM is maintained, excessive reduction in valve operating pressure is prevented, and external air does not flow into the battery.
As a result, it is possible to prevent ignition caused by the inflow of air or oxygen from the outside, especially in nickel-hydrogen storage batteries and lithium batteries.

【0017】さらに、弾性弁体がTPEとEPDMの混
合物であるため、酸素分子が弾性弁体の表面から内部に
浸透しにくく、酸化による劣化に伴うEPDMの架橋構
造の破壊が抑制され、弁作動圧力の長期にわたる安定
化、すなわち信頼性の確保が可能となる。
Further, since the elastic valve body is a mixture of TPE and EPDM, it is difficult for oxygen molecules to permeate from the surface of the elastic valve body into the interior, and the destruction of the cross-linked structure of EPDM due to deterioration due to oxidation is suppressed, and valve operation It is possible to stabilize the pressure over a long period of time, that is, to secure reliability.

【0018】なお、EPDMとTPEとの混合比率につ
いては、1:2以上であれば、TPEによるEPDMの
酸化抑制効果により、通常使用温度範囲における弁作動
圧力の低下を防止できる。一方、1:4以下であれば、
硬質相の増加により、弾性弁体の硬度が過度に大きくな
ることもなく、弁作動圧力の設定も容易である。
If the mixing ratio of EPDM and TPE is 1: 2 or more, the reduction of the valve operating pressure in the normal operating temperature range can be prevented due to the effect of suppressing the oxidation of EPDM by TPE. On the other hand, if 1: 4 or less,
By increasing the hard phase, the hardness of the elastic valve body does not become excessively large, and the valve operating pressure can be easily set.

【0019】したがって、EPDMとTPEの混合比率
は、1:2〜1:4が望ましい。
Therefore, the mixing ratio of EPDM and TPE is preferably 1: 2 to 1: 4.

【0020】[0020]

【実施例】以下、本発明の一実施例について、図面を参
照しながら説明する。
An embodiment of the present invention will be described below with reference to the drawings.

【0021】(実施例1)図3に示す安全弁装置を構成
し、EPDMとTPEとの混合比率についての検討を行
った。
(Embodiment 1) The safety valve device shown in FIG. 3 was constructed to examine the mixing ratio of EPDM and TPE.

【0022】EPDMとTPEを重量比率1:2、1:
3および1:4の割合で混合し、EPDM部分を架橋処
理した弾性弁体をそれぞれ作成し、これらの弁体を用い
た本発明品の安全弁装置A、BおよびCを構成した。
The weight ratio of EPDM and TPE is 1: 2, 1: 2.
3 and 1: 4 were mixed to prepare elastic valve bodies in which the EPDM portion was crosslinked, and safety valve devices A, B and C of the present invention were constructed using these valve bodies.

【0023】また、比較例として、上記弾性弁体のEP
DMとTPEとの比率を1:1とした安全部弁装置D
を、従来例として、EPDMのみから作成した弾性弁体
を用いた安全弁装置Eを構成した。
As a comparative example, EP of the above-mentioned elastic valve body is used.
Safety unit valve device D with a ratio of DM to TPE of 1: 1
As a conventional example, a safety valve device E using an elastic valve element made only from EPDM was constructed.

【0024】上記A〜Eの5種類の安全弁装置を用いて
弾性弁体の耐熱劣化特性についての検討を行った。雰囲
気温度65℃の環境下において一定期間保存した後、弁
作動圧力を測定した。保存期間と弁作動圧維持率との関
係を図1に示す。この図1から明らかなように、従来の
EPDMのみを用いた安全弁装置Eに比べ、EPDMと
TPEを混合した安全弁装置A、B、CおよびDの熱に
よる劣化度合いは小さくなっている。また同時に、EP
DMに対するTPEの重量比率を大きくすることで、耐
熱性が向上することもわかる。EPDMとTPEとの混
合比率について、本発明の1:2以上であれば、TPE
によるEPDMの酸化抑制効果により、弁作動圧の低下
を防止できることは明らかである。
Using the above five types of safety valve devices A to E, the heat deterioration resistance of the elastic valve body was examined. The valve operating pressure was measured after storing for a certain period in an environment of an ambient temperature of 65 ° C. FIG. 1 shows the relationship between the storage period and the valve operating pressure maintenance rate. As is clear from FIG. 1, the degree of deterioration of the safety valve devices A, B, C, and D in which EPDM and TPE are mixed due to heat is smaller than that of the conventional safety valve device E using only EPDM. At the same time, EP
It can also be seen that the heat resistance is improved by increasing the weight ratio of TPE to DM. If the mixing ratio of EPDM and TPE is 1: 2 or more according to the present invention, TPE
It is clear that the decrease in valve operating pressure can be prevented by the oxidation inhibiting effect of EPDM.

【0025】このことから本発明の密閉型電池の安全弁
装置は、弾性弁体をEPDMとTPEを1:2〜1:4
の重量比率で混合した後、EPDMを架橋処理している
ため、EPDMの劣化による弁作動圧の低下を防止で
き、長期信頼性の高い安全弁装置を提供できる。
From the above, in the safety valve device for a sealed battery of the present invention, the elastic valve element is made EPDM and TPE 1: 2 to 1: 4.
Since EPDM is cross-linked after being mixed at a weight ratio of 1, the decrease in valve operating pressure due to deterioration of EPDM can be prevented, and a safety valve device having high long-term reliability can be provided.

【0026】(実施例2)本発明のEPDMとTPEと
を1:3の重量比率で混合し、EPDM部分を架橋処理
した弾性弁体により構成された安全弁装置を用いて、公
称容量1600mAhのAサイズの密閉型ニッケル・水
素蓄電池を作製し、この電池を電池Fとした。
(Example 2) EPDM and TPE of the present invention were mixed in a weight ratio of 1: 3, and a safety valve device composed of an elastic valve body obtained by crosslinking the EPDM portion was used to measure A with a nominal capacity of 1600 mAh. A sealed nickel-hydrogen storage battery having a size was produced, and this battery was named battery F.

【0027】一方、比較例として、従来の弾性弁体にE
PDMのみを用いた安全部弁装置を使用し、上記同様に
作製したニッケル・水素蓄電池を電池Gとした。また、
TPEのみからなる弾性弁体を有する安全弁装置を用い
た電池Hを構成した。
On the other hand, as a comparative example, the conventional elastic valve body has E
A nickel-hydrogen storage battery manufactured in the same manner as above was used as a battery G using the safety valve device using only the PDM. Also,
A battery H was constructed using a safety valve device having an elastic valve element made of TPE only.

【0028】上記F〜Hの3種類の電池を各々20セル
づつについて、充電器の制御不良を想定した8A(5
C)の電流で充電を行い、電池温度の測定すると同時
に、破裂および発火に至った電池を計数した。その結果
を表1に示す。
For each of the three types of batteries F to H, 20 cells each, 8A (5
The battery was charged with the current of C), the battery temperature was measured, and at the same time, the number of batteries that ruptured and ignited was counted. Table 1 shows the results.

【0029】[0029]

【表1】 [Table 1]

【0030】本発明による電池Fでは、充電時に過大な
電流が電池に流れ込み、電池温度が上昇し、電池内部よ
りガス漏れが発生したが、破裂および発火に至った電池
は認められなかった。
In the battery F according to the present invention, an excessive current flows into the battery during charging, the battery temperature rises, and gas leaks from the inside of the battery, but no battery that ruptured or ignited was observed.

【0031】これに対して電池Gでは、電池温度が15
0℃付近に達した時に1セル、170℃付近で1セル、
180℃付近で2セル、200℃付近で4セルが、破裂
した。これらはいずれも金属ケースの封口部から封口板
が外れた状態となった。
On the other hand, in the battery G, the battery temperature is 15
1 cell when reaching around 0 ° C, 1 cell at around 170 ° C,
Two cells burst around 180 ° C and four cells burst around 200 ° C. In all of these cases, the sealing plate was removed from the sealing portion of the metal case.

【0032】一方電池Hでは、破裂に至った電池は確認
できなかったが、電池温度が230℃付近まで上昇した
時、3セルより発火が認められた。なお、電池F、Gの
各電池は、過大電流での充電を施しても、発火しなかっ
た。
On the other hand, in the battery H, no ruptured battery was found, but when the battery temperature rose to around 230 ° C., ignition was recognized from 3 cells. The batteries F and G did not ignite even when charged with an excessive current.

【0033】上記F〜Hまでの3種類の電池について、
電池の温度上昇による安全装置の弁作動圧力値の変動を
測定した結果を図2に示す。
Regarding the above three types of batteries F to H,
FIG. 2 shows the result of measuring the fluctuation of the valve operating pressure value of the safety device due to the temperature rise of the battery.

【0034】電池Fの弁作動圧力は、電池温度の上昇に
従ってTPEが軟化あるいは溶出することにより、10
0℃付近から大幅に低下している。これに伴いガス排気
口からのガス排出速度は増大する。しかし、TPEの溶
出が沈静化した120℃から250℃までは、架橋形成
されたEPDMにより弾性弁体の閉塞機能が維持され、
ほぼ一定の弁作動圧力を保持している。
The valve operating pressure of the battery F is 10 because the TPE softens or elutes as the battery temperature rises.
Significantly decreased from around 0 ° C. Along with this, the gas discharge rate from the gas exhaust port increases. However, from 120 ° C to 250 ° C when the elution of TPE has subsided, the occluding function of the elastic valve body is maintained by the crosslinked EPDM,
It maintains a nearly constant valve operating pressure.

【0035】これに対して電池Gの安全弁装置の弁作動
圧力は、EPDMの熱膨脹によって、100℃付近から
緩やかに上昇している。このことから、ガス排気口から
のガス排出速度が低下していることがわかる。一方、電
池Hの安全弁装置の弁作動圧力は、温度上昇によってT
PEの軟化あるいは溶出が進行し、ガス排出速度は上昇
していくが、250℃付近で弾性弁体の閉塞機能を示さ
なくなっていることは明白である。
On the other hand, the valve operating pressure of the safety valve device of the battery G gradually rises from around 100 ° C. due to the thermal expansion of EPDM. From this, it can be seen that the gas discharge rate from the gas exhaust port is decreasing. On the other hand, the valve operating pressure of the safety valve device of the battery H is T
Although the softening or elution of PE progresses and the gas discharge rate increases, it is clear that the elastic valve body does not exhibit the closing function at around 250 ° C.

【0036】このような高温における電池内部で発生し
たガスの安全な排出速度を維持し、且つ電池内への大気
の流入を防ぐ効果は、上記した種々の検討を行った結
果、4〜8kg/cm2の作動圧を保持することにより
得られる。
The effect of maintaining the safe discharge rate of the gas generated inside the battery at such a high temperature and preventing the inflow of the atmosphere into the battery is 4 to 8 kg / Obtained by holding the working pressure of cm 2 .

【0037】本発明の密閉型電池の安全弁装置は、弾性
弁体をTPEが混合されたEPDMの架橋形成された構
成とすることにより、電池内部にガスの異常発生が生じ
た場合に、TPEを形成している樹脂成分が、軟化ある
いは溶け出すことにより弾性弁体としての作動圧力が低
下し、電池内圧の上昇を押さえ、電池の破裂を防止でき
る。さらに、架橋されたEPDMがTPEを取り囲んで
覆っているため、弾性弁体の閉塞機能は維持できるた
め、過度の弁作動圧力の低下が抑制される。これによ
り、特にニッケル・水素蓄電池の発火を防止できる。
The sealed valve safety valve device of the present invention has a structure in which the elastic valve element is formed by the cross-linking of EPDM mixed with TPE, so that when abnormal gas generation occurs in the battery, the TPE By softening or melting the formed resin component, the operating pressure of the elastic valve body is lowered, and the rise of the internal pressure of the battery can be suppressed to prevent the battery from bursting. Further, since the cross-linked EPDM surrounds and covers the TPE, the closing function of the elastic valve body can be maintained, and an excessive decrease in valve operating pressure is suppressed. This can prevent ignition of the nickel-hydrogen storage battery.

【0038】[0038]

【発明の効果】以上のように本発明によれば、弁作動圧
力を長期にわたって安定に維持することで、信頼性を確
保するだけでなく、急激な温度上昇に伴う電池内圧の急
上昇に対応し、さらに電池の発火を防止する安全性の高
い安全弁装置を有した密閉型電池を提供することができ
る。
As described above, according to the present invention, by maintaining the valve operating pressure stable over a long period of time, not only the reliability is secured, but also the sudden increase in the battery internal pressure due to the rapid temperature rise is coped with. Further, it is possible to provide a sealed battery having a highly safe safety valve device that prevents ignition of the battery.

【図面の簡単な説明】[Brief description of drawings]

【図1】保存時間と弁作動圧維持率との関係を示す図FIG. 1 is a diagram showing the relationship between storage time and valve operating pressure maintenance rate.

【図2】電池温度と安全装置の弁作動圧力との関係を示
す図
FIG. 2 is a diagram showing a relationship between a battery temperature and a valve operating pressure of a safety device.

【図3】密閉型電池の上部縦断面図FIG. 3 is a vertical cross-sectional view of the upper portion of the sealed battery.

【符号の説明】[Explanation of symbols]

1 ケース 2 封口板 2a ガス通気孔 3 ガスケット 5 正極端子 5a ガス排気口 6 弁室 7 弾性弁体 1 Case 2 Sealing Plate 2a Gas Vent 3 Gasket 5 Positive Terminal 5a Gas Exhaust 6 Valve Chamber 7 Elastic Valve

───────────────────────────────────────────────────── フロントページの続き (72)発明者 浪花 満 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 広島 敏久 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 竹内 康弘 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mitsuru Naniwa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Toshihisa Hiroshima, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Yasuhiro Takeuchi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】発電要素を収納した電池容器と、この電池
容器の開口部を密閉する安全弁装置とを備え、前記安全
弁装置は中央部にガス通気孔を有する皿状封口板と、こ
の封口板上に配置され前記ガス通気孔を閉塞する弾性弁
体と、この弁体を弁室内に位置させたキャップ状正極端
子とにより構成されており、前記弾性弁体は、熱可塑性
エラストマーとエチレンプロピレンゴムとが混合され、
前記エチレンプロピレンゴムが架橋形成されていること
を特徴とする密閉型電池。
1. A battery container accommodating a power generating element and a safety valve device for sealing an opening of the battery container, the safety valve device having a plate-like sealing plate having a gas vent hole in a central portion thereof, and the sealing plate. The elastic valve body is disposed above and closes the gas vent hole, and a cap-shaped positive electrode terminal in which the valve body is located in the valve chamber. The elastic valve body is made of a thermoplastic elastomer and ethylene propylene rubber. And are mixed,
A sealed battery, wherein the ethylene propylene rubber is crosslinked.
【請求項2】弾性弁体を構成する熱可塑性エラストマー
は、硬質相と軟質相の2相から形成され、硬質相にはポ
リプロピレンまたはポリエチレンを、軟質相にはエチレ
ンプロピレンゴムをそれぞれ用い、エチレンプロピレン
ゴムと前記熱可塑性エラストマーとの混合比率が、1:
2〜1:4であることを特徴とする請求項1記載の密閉
型電池。
2. A thermoplastic elastomer constituting an elastic valve body is formed of two phases, a hard phase and a soft phase, polypropylene or polyethylene is used for the hard phase, and ethylene propylene rubber is used for the soft phase. The mixing ratio of the rubber and the thermoplastic elastomer is 1:
The sealed battery according to claim 1, wherein the sealed battery has a ratio of 2 to 1: 4.
【請求項3】発電要素を収納した電池容器と、この電池
容器の開口部を密閉する安全弁装置とを備え、安全弁装
置は中央部にガス通気孔を有する皿状封口板と、この封
口板上に配置され前記ガス通気孔を閉塞する弾性弁体
と、この弁体を弁室内に位置させたキャップ状正極端子
により構成されており、前記安全弁装置の作動圧力を1
00〜120℃において4〜8kg/cm2とし、25
0℃までこの作動圧力を保持することを特徴とする密閉
型電池。
3. A battery container accommodating a power generating element, and a safety valve device for sealing an opening of the battery container, the safety valve device having a plate-like sealing plate having a gas vent hole in a central portion, and a sealing plate on the sealing plate. And a cap-shaped positive electrode terminal in which the valve body is positioned in the valve chamber, and the operating pressure of the safety valve device is set to 1
It is 4 to 8 kg / cm 2 at 00 to 120 ° C. and 25
A sealed type battery characterized in that this operating pressure is maintained up to 0 ° C.
【請求項4】弾性弁体が、熱可塑性エラストマーとエチ
レンプロピレンゴムとを混合し、前記エチレンプロピレ
ンゴムが架橋形成されていることを特徴とする請求項3
記載の密閉型電池。
4. The elastic valve body is characterized in that a thermoplastic elastomer and ethylene propylene rubber are mixed, and the ethylene propylene rubber is crosslinked.
The sealed battery described.
JP07871195A 1995-04-04 1995-04-04 Sealed battery Expired - Lifetime JP3158946B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP07871195A JP3158946B2 (en) 1995-04-04 1995-04-04 Sealed battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP07871195A JP3158946B2 (en) 1995-04-04 1995-04-04 Sealed battery

Publications (2)

Publication Number Publication Date
JPH08273649A true JPH08273649A (en) 1996-10-18
JP3158946B2 JP3158946B2 (en) 2001-04-23

Family

ID=13669459

Family Applications (1)

Application Number Title Priority Date Filing Date
JP07871195A Expired - Lifetime JP3158946B2 (en) 1995-04-04 1995-04-04 Sealed battery

Country Status (1)

Country Link
JP (1) JP3158946B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0793283A1 (en) * 1996-02-28 1997-09-03 Matsushita Electric Industrial Co., Ltd. Sealed battery
WO2001063680A1 (en) * 2000-02-28 2001-08-30 Matsushita Electric Industrial Co., Ltd. Sealing plate, cell using the sealing plate, and method of manufacturing the cell
WO2019212164A1 (en) * 2018-05-02 2019-11-07 삼성에스디아이(주) Secondary battery

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0793283A1 (en) * 1996-02-28 1997-09-03 Matsushita Electric Industrial Co., Ltd. Sealed battery
WO2001063680A1 (en) * 2000-02-28 2001-08-30 Matsushita Electric Industrial Co., Ltd. Sealing plate, cell using the sealing plate, and method of manufacturing the cell
US7858217B1 (en) 2000-02-28 2010-12-28 Panasonic Corporation Top sealing plate, battery using the top sealing plate, and method of manufacturing the battery
WO2019212164A1 (en) * 2018-05-02 2019-11-07 삼성에스디아이(주) Secondary battery

Also Published As

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JP3158946B2 (en) 2001-04-23

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