JP3158946B2 - Sealed battery - Google Patents
Sealed batteryInfo
- Publication number
- JP3158946B2 JP3158946B2 JP07871195A JP7871195A JP3158946B2 JP 3158946 B2 JP3158946 B2 JP 3158946B2 JP 07871195 A JP07871195 A JP 07871195A JP 7871195 A JP7871195 A JP 7871195A JP 3158946 B2 JP3158946 B2 JP 3158946B2
- Authority
- JP
- Japan
- Prior art keywords
- battery
- epdm
- valve body
- safety valve
- tpe
- 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.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/30—Arrangements for facilitating escape of gases
- H01M50/317—Re-sealable arrangements
- H01M50/325—Re-sealable arrangements comprising deformable valve members, e.g. elastic or flexible valve members
-
- 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
Description
【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 improving the safety of the battery.
【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 In recent years, with the spread of various portable devices, batteries,
In particular, rechargeable secondary batteries are used in a wide range of fields. Conventionally, lead-acid batteries and nickel-cadmium batteries have been used as batteries used in these devices, but nickel-metal hydride 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, batteries using an aqueous solution, such as a lead storage battery, a nickel-cadmium storage battery, or a nickel-hydrogen storage battery, consume gas generated inside the battery by a so-called Neumann method. By doing so, sealing is enabled.
【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, in a battery using a non-aqueous electrolyte such as a lithium ion secondary battery, sealing has been attempted 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, failure of the charger, misuse of the battery,
When an abnormal situation occurs due to an external short circuit or the like, the internal pressure of the battery increases, which may lead to rupture. In order to prevent the battery from exploding, the secondary battery is provided with a safety valve device such that when the internal pressure exceeds a preset value, gas generated inside the battery is released to the outside.
【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 an upper longitudinal sectional view of the sealed battery. In FIG. 3, a metal case 1 as a battery container is shown.
A metal sealing plate 2 having a gas vent hole 2a formed in the center portion is mounted and fixed by a caulking process via a gasket 3 which plays a role of maintaining insulation and airtightness on the upper portion of the case 1. . Although not shown in detail in the above-mentioned case 1, a power generating element 4 composed of an electrode group and an alkaline electrolyte, which is obtained by superposing a positive electrode plate and a negative electrode plate via a separator and winding them in a spiral shape, is not shown. It is stored. Further, the sealing plate 2 is provided with a cap-shaped positive electrode terminal 5 which is also used for constituting a safety valve device. This positive terminal 5
Has a cap shape, and has a gas exhaust port 5
a and holes are formed. A valve chamber 6 is formed in a space surrounded by the positive electrode terminal 5 and the sealing plate 2.
The elastic valve body 7 is housed 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。[0007] In the sealed battery having the above-described configuration, if the internal pressure of the battery rises due to an excessive inflow of charging current due to a failure of the charger or an overdischarge accompanied by reversal, a high voltage The gas in the state pushes up the elastic valve body and is discharged from the gas exhaust port 5 a 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 above-mentioned safety valve device which is usually used is set so that when the internal pressure of the battery reaches 10 kg / cm 2 or more, gas is released to the outside. Therefore, if overcharging is performed to the extent that no sudden gas generation occurs,
As the gas absorbing capacity of the negative electrode decreases, the internal pressure increases. At this time, even if the gas inside the battery is released to the outside, there is no problem if the charging is stopped and the internal pressure of the battery drops, so that the safety valve device returns to its original shape and can be used again. In order to enable quick charging, the rated allowable pressure of the safety valve may be increased to about 20 kg / cm 2 .
【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 compressibility, the deformation rate of the elastic body is reduced and the allowable value of the internal pressure is increased. When the gas flows into the battery and an abnormal gas is generated, the safety valve device using such an elastic body cannot keep the discharge speed from the gas exhaust port equal to the gas generation speed inside the battery. Therefore, there is a possibility that the internal pressure of the battery suddenly increases and the battery may burst. Also, it is conceivable that due to the temperature rise inside the battery, the elastic rubber valve body thermally expands to the full of the valve chamber, and the original valve body operation function cannot be maintained.
【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 Patent Application Laid-Open No. 5-41204, the melting point of at least one of the packing material and the safety valve is set to 2 in order to ensure safety when the battery is thrown into a fire.
It is described that the temperature is set to 70 ° C. or lower. However, when an excessive current is applied to the battery and the battery temperature reaches about 100 ° C., the hydrogen stored in the negative electrode starts to be released, and the internal pressure of the battery rapidly rises, leading to rupture. The configuration described in the above publication may not be able to cope with a rupture 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 olefin-based thermoplastic elastomer is used for the elastic valve body. When the battery temperature rises, the valve operating pressure becomes too low due to the softening or melting of the thermoplastic elastomer,
The gas vent is substantially opened. As a result, outside air flows into the battery, which promotes an 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 mainly composed of ethylene propylene rubber gradually loses rubber elasticity mainly by oxidation. Due to this change in rubber elasticity with time, the valve operating pressure of the safety valve device is reduced, so that it is difficult to set the valve operating pressure for ensuring long-term reliability such as prevention of electrolyte leakage.
【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。[0013] 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 in 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, a sealed battery according to the present invention comprises a thermoplastic elastomer (hereinafter referred to as TPE) provided in an elastic valve body incorporated in a safety valve device.
And ethylene propylene rubber (hereinafter referred to as EPDM), and a cross-linked EPDM is used.
The valve operating pressure of the safety valve device at 00 to 120 ° C is 4 to
The pressure was set to 8 kg / cm 2 and the valve operating pressure was maintained at 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 for providing thermoplasticity and a soft phase for providing elasticity. When a large current exceeding the set value flows, thereby increasing the battery temperature and causing abnormal gas generation, the hard phase forming the TPE dissolves, and the operating pressure as the elastic valve body decreases. However, the discharge speed from the gas exhaust port substantially increases. Since the discharge speed follows the internal gas generation speed, an increase in battery internal pressure can be suppressed, and the battery can be prevented 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。[0016] Further, EPDM is itself crosslinked after being mixed with TPE, so that EPDM is softened at high temperature even if TPE is softened.
Since the crosslinked structure of DM is maintained, an excessive decrease in the valve operating pressure is prevented, and outside air does not flow into the battery.
This can prevent ignition caused by the inflow of air or oxygen from the outside such as a nickel-metal hydride storage battery or a lithium battery.
【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, oxygen molecules hardly permeate from the surface of the elastic valve body to the inside, and the destruction of the crosslinked structure of EPDM due to deterioration due to oxidation is suppressed, and the valve operation Pressure can be stabilized for a long time, that is, reliability can be ensured.
【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。When the mixing ratio of EPDM and TPE is 1: 2 or more, the effect of suppressing oxidation of EPDM by TPE can prevent a decrease in valve operating pressure in a normal operating temperature range. On the other hand, if 1: 4 or less,
Due to the increase in the hard phase, the hardness of the elastic valve body does not become excessively large, and the setting of the valve operating pressure is easy.
【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 desirably 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。Example 1 The safety valve device shown in FIG. 3 was constructed, and the mixing ratio between EPDM and TPE was examined.
【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。EPDM and TPE are used in a weight ratio of 1: 2, 1:
Elastic valve bodies were prepared by mixing at a ratio of 3 and 1: 4 to crosslink the EPDM portion, respectively, and safety valve devices A, B and C of the present invention using these valve bodies were constructed.
【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, the elastic valve element EP
Safety part valve device D in which the ratio of DM to TPE is 1: 1
As a conventional example, a safety valve device E using an elastic valve body made of only 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 five types of safety valve devices A to E described above, the heat resistance deterioration characteristics of the elastic valve body were examined. After storing for a certain period of time in an environment of an atmospheric temperature of 65 ° C., the valve operating pressure was measured. 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, which are a mixture of EPDM and TPE, 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 increasing the weight ratio of TPE to DM improves heat resistance. If the mixing ratio of EPDM and TPE is 1: 2 or more in the present invention, TPE
It is clear that the reduction of the valve operating pressure can be prevented by the oxidation inhibitory 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, the safety valve device for a sealed battery according to the present invention has a structure in which the elastic valve element is composed of EPDM and TPE in a ratio of 1: 2 to 1: 4.
After mixing at a weight ratio of EPDM, the EPDM is subjected to a cross-linking treatment, so that a decrease in valve operating pressure due to deterioration of the EPDM can be prevented, and a long-term reliable safety valve device 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 of the present invention and TPE were mixed at a weight ratio of 1: 3, and a safety valve device composed of an elastic valve body in which an EPDM portion was subjected to a cross-linking treatment was used, and A having a nominal capacity of 1600 mAh was used. A sealed nickel-metal hydride storage battery having a size was produced, and this battery was designated as 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, E
A nickel-hydrogen storage battery manufactured in the same manner as above using a safety valve device using only the PDM was used as a battery G. Also,
A battery H was constructed using a safety valve device having an elastic valve body made of only TPE.
【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 described above, each of the 20 cells is assumed to have a bad control of the charger.
The battery was charged with the current of C), the battery temperature was measured, and at the same time, the number of batteries that had exploded or 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 flowed into the battery at the time of charging, the battery temperature increased, and gas leaked from the inside of the battery. However, no battery which burst or ignited was recognized.
【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
One cell at around 0 ° C, one cell at around 170 ° C,
Two cells burst around 180 ° C. and four cells burst around 200 ° C. In each case, the sealing plate came off 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 case of the battery H, no explosive battery could be confirmed. However, when the battery temperature rose to around 230 ° C., ignition was observed from three cells. In addition, each of 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 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 increased by 10% as the TPE softens or elutes as the battery temperature increases.
It has dropped significantly from around 0 ° C. Accordingly, the gas discharge speed from the gas outlet increases. However, from 120 ° C. to 250 ° C. where the elution of TPE subsides, the closing function of the elastic valve body is maintained by the cross-linked EPDM,
It maintains a substantially 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 the EPDM. This indicates that the gas exhaust speed from the gas exhaust port has decreased. On the other hand, the valve operating pressure of the safety valve device of the battery H becomes T
Although the softening or elution of PE progresses, the gas discharge speed increases, but it is clear that at around 250 ° C., the elastic valve element does not exhibit the closing function.
【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 effects of maintaining the safe discharge speed of the gas generated inside the battery at such a high temperature and preventing the inflow of the atmosphere into the battery have been examined as a result of the various studies described above. It is obtained by maintaining a 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。In the safety valve device for a sealed battery according to the present invention, the elastic valve body is formed by cross-linking EPDM mixed with TPE. The operating pressure of the elastic valve body is reduced by the softening or melting of the formed resin component, the increase in the internal pressure of the battery is suppressed, and the rupture of the battery can be prevented. Further, since the cross-linked EPDM surrounds and covers the TPE, the closing function of the elastic valve body can be maintained, so that an excessive decrease in the valve operating pressure is suppressed. Thereby, the ignition of the nickel-metal hydride storage battery can be particularly prevented.
【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 stably for a long period of time, it is possible not only to ensure reliability but also to cope with a sudden increase in battery internal pressure due to a rapid temperature rise. Further, it is possible to provide a sealed battery having a highly safe safety valve device for preventing the battery from firing.
【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 a relationship between a storage time and a 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 an upper longitudinal sectional view of a sealed battery.
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 DESCRIPTION OF SYMBOLS 1 Case 2 Sealing plate 2a Gas ventilation hole 3 Gasket 5 Positive electrode terminal 5a Gas exhaust port 6 Valve chamber 7 Elastic valve element
───────────────────────────────────────────────────── 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 (56)参考文献 特開 平５−41204（ＪＰ，Ａ) 特開 平４−36953（ＪＰ，Ａ) 特開 平３−159057（ＪＰ，Ａ) 特開 昭59−160955（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 2/12 102 C08L 23/16 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuru Namana 1006 Kadoma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshihisa Hiroshima 1006 Kadoma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd No. (72) Inventor Yasuhiro Takeuchi 1006 Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-41204 (JP, A) JP-A-4-36953 (JP, A) JP-A-3-159057 (JP, A) JP-A-59-160955 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01M 2/12 102 C08L 23/16
Claims (2)
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、
かつ前記エチレンプロピレンゴムが架橋形成されてお
り、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
する密閉型電池。1. A battery container accommodating a power generating element, a safety valve device for closing an opening of the battery container, wherein the safety valve device has a dish-shaped sealing plate having a gas vent hole in a central portion, and the sealing plate. An elastic valve body disposed on the top and closing the gas vent hole, and a cap-shaped positive electrode terminal having the valve body positioned in the valve chamber, the elastic valve body is made of a thermoplastic elastomer and ethylene propylene rubber. Is mixed with
And the ethylene propylene rubber is crosslinked and
Ethylene propylene rubber and the thermoplastic elastomer
Mixing ratio of over is 1: 2 to 1: sealed battery according to claim 4 der Rukoto.
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
ムであることを特徴とする請求項１記載の密閉型電池。Wherein said thermoplastic elastomer is formed from two phases of hard and soft phases, polypropylene or polyethylene to the hard phase, the soft phase is ethylene propylene rubber
The sealed battery of claim 1, wherein it is a beam.
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 JPH08273649A (en) | 1996-10-18 |
| JP3158946B2 true 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) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69622525T2 (en) * | 1996-02-28 | 2003-02-27 | Matsushita Electric Ind Co Ltd | sealing battery |
| JP3580213B2 (en) | 2000-02-28 | 2004-10-20 | 松下電器産業株式会社 | Sealing plate for cylindrical battery |
| KR102604484B1 (en) * | 2018-05-02 | 2023-11-22 | 삼성에스디아이 주식회사 | Secondary battery |
-
1995
- 1995-04-04 JP JP07871195A patent/JP3158946B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08273649A (en) | 1996-10-18 |
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