JP2004192870A

JP2004192870A - Lead storage battery and method of manufacturing the same

Info

Publication number: JP2004192870A
Application number: JP2002357166A
Authority: JP
Inventors: Masaaki Shiomi; 正昭塩見
Original assignee: Japan Storage Battery Co Ltd
Current assignee: Japan Storage Battery Co Ltd
Priority date: 2002-12-09
Filing date: 2002-12-09
Publication date: 2004-07-08
Anticipated expiration: 2022-12-09
Also published as: JP4904658B2

Abstract

【課題】本発明の解決しようとする課題は、Ｓｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子を有する制御弁式鉛蓄電池あるいは電解液が十分に存在する開放型鉛蓄電池において、Ｓｂの存在によって早期容量低下が防止されると共に、Ｓｂの負極への弊害を極力抑制し、優れたサイクル寿命を有する鉛蓄電池の製造方法およびそれによって製造された蓄電池を提供することにある。
【解決手段】Ｓｂの弊害を抑制するために、負極板にオイルを一定量添加する、正極活物質中にＳｎを一定量添加する、負極板にリグニンを一定量添加するあるいは／および負極活物質量／正極活物質量の比を０．６以上にすることを特徴とするものである。
【選択図】図２An object of the present invention is to provide a control valve type lead-acid battery or electrolyte having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less. In a sufficiently existing open-type lead-acid battery, the presence of Sb prevents the early capacity reduction and suppresses the adverse effect of Sb on the negative electrode as much as possible. To provide a storage battery.
In order to suppress the adverse effects of Sb, a certain amount of oil is added to a negative electrode plate, a certain amount of Sn is added to a positive electrode active material, a certain amount of lignin is added to a negative electrode plate, and / or a negative electrode active material is added. The ratio of the amount / amount of the positive electrode active material is set to 0.6 or more.
[Selection] Fig. 2

Description

【０００１】
【発明の属する技術分野】
本発明は鉛蓄電池およびその製造方法に関する。
【０００２】
【従来の技術】
鉛蓄電池の内で特に制御弁式鉛蓄電池は無漏液・無保守の特性を有していることが特徴である。無漏液とは、電解液がセパレータのみに含浸・保持され流動電解液の存在しない構造で、蓄電池を横置きにしても電解液の液漏れがないものをいう。また、無保守とは、前記蓄電池の特徴である密閉反応機能により正常な充電においてはガスが発生せず、電解液の減少がほとんどなく補液といった保守が不必要な特性をいう。
【０００３】
以上のような優れた特性を有していることから、近年、制御弁式鉛蓄電池は多方面にその用途が拡大している。それに伴って、高信頼性、高エネルギー密度化、長寿命化の要求が強くなってきている。
【０００４】
上述した制御弁式鉛蓄電池内における密閉反応は、下記の（１）、（２）および（３）式で示される。
（正極）Ｈ_２Ｏ＝１／２Ｏ_２＋２Ｈ^＋＋２ｅ⁻・・・・・・・・・・・（１）
（負極）Ｐｂ＋１／２Ｏ_２＋２Ｈ^＋＋ＳＯ_４ ^２−＝ＰｂＳＯ_４＋Ｈ_２Ｏ・・・・・・（２）
ＰｂＳＯ_４＋２ｅ⁻＝Ｐｂ＋ＳＯ_４ ^２−・・・・・・・・・・（３）
上記のように、正極で水（Ｈ_２Ｏ）が分解され、酸素ガス（Ｏ_２）が発生するが、上述したように該蓄電池は、電解液がセパレータのみに含浸・保持され流動電解液の存在しない構造であるため、該Ｏ_２はセパレータを貫通して容易に負極に移動し、Ｐｂと反応してＰｂＳＯ_４とＨ_２Ｏが生成される。すなわち、（１）式で失われたＨ_２Ｏが（２）式で再生されたことになり全体として電解液が減少しない。
【０００５】
また、（２）式で生成されたＰｂＳＯ_４は（３）式に示すように負極の充電反応によって、Ｐｂに還元され、負極では充電時に水素ガス（Ｈ_２）が発生しない。すなわち。充電時に酸素ガスおよび水素ガスのいずれも発生しない。
【０００６】
しかしながら、負極の自己放電が多くなると水素ガスが余分に発生し、上記（１）、（２）および（３）式によるＨ_２Ｏの再生サイクルのバランスが崩れ、負極が充電不足になり、それが継続して起こると、負極がＰｂＳＯ_４の大きな結晶となる、いわゆる、サルフェイション現象が起こり充電できなくなり、短寿命になる。
【０００７】
したがって、制御弁式鉛蓄電池においては、正・負極格子に自己放電量の少ないＰｂ、Ｐｂ−Ｃａ合金あるいはＰｂ−Ｃａ−Ｓｎ合金が通常採用されている。
【０００８】
しかしながら、上記格子は、絶えず充電をしながら使用する、トリクルあるいはフロート使用では問題ないが、充・放電を絶えず繰り返すサイクル使用で、特に、放電量が少なく、過充電される使用状態では正極格子の酸化が進み過ぎるため、放電時にその部分が優先的に放電し、正極格子と活物質との界面に硫酸鉛の絶縁層が形成され、早期に容量が低下（早期容量低下、また、ＰｒｅｍａｔｕｒｅＣａｐａｃｉｔｙＬｏｓｓ略してＰＣＬともいう）するといった問題が発生する。
【０００９】
上記、早期容量低下に関しては、制御弁式鉛蓄電池だけではなく、正・負極にＳｂを含まないＰｂ、Ｐｂ−ＣａあるいはＰｂ−Ｃａ−Ｓｎ合金格子を用い、電解液が十分に存在する開放型鉛蓄電池においても同様の現象が見られる。
【００１０】
上記対策の一つとして、負極格子にはＰｂ、Ｐｂ−Ｃａ合金あるいはＰｂ−Ｃａ−Ｓｎ合金を使用し、正極には、Ｓｂ濃度が０．５質量％以上、１．５質量％以下とＳｂ濃度の低い（低アンチモンと称している）Ｐｂ−Ｓｂ系合金格子を使用する方法が提案されている。正極にＳｂが存在することによって、原因は明確でないが上述したサイクル使用での早期容量低下が発生しなくなる。しかし、該Ｓｂが正極から電解液中に溶出し負極に析出すると負極の水素過電圧を下げ、水素ガスの発生を促進し、上述した密閉反応サイクルのバランスが崩れ、制御弁式鉛蓄電池の機能を失い負極板が充電不足になり蓄電池性能が劣化する。開放型蓄電池においても、水素過電圧の低下により、充電効率が低下し、電解液の減少が加速され性能が劣化する問題を抱えている。
【００１１】
【発明が解決しようとする課題】
Ｓｂ濃度、０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子を有する鉛蓄電池において、Ｓｂの存在によって早期容量低下が防止されると共に、Ｓｂの負極への弊害を極力抑制し、優れたサイクル寿命を有する鉛蓄電池の製造方法および鉛蓄電池を提供することにある。
【００１２】
【課題を解決するための手段】
課題を解決するための手段として、請求項１によれば、Ｓｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子を有する鉛蓄電池の製造方法において、
負極活物質中に負極活物質量に対して０．３質量％以上、０．７質量％以下のオイルを添加することを特徴とするものである。
【００１３】
鉛蓄電池、特に制御弁式鉛蓄電池において、Ｓｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金を正極格子に使用した場合、Ｓｂの存在により、該蓄電池のサイクル使用における早期容量低下は抑制できるが、Ｓｂが電解液中に溶出し、負極に析出すると水素過電圧を下げ、水素ガスの発生を促進し、上述した密閉反応サイクルのバランスが崩れ、負極板が充電不足になり、サルフェイション化し蓄電池の性能劣化が促進される問題を抱えていた。該Ｓｂの弊害を抑制する手段の一つとして負極活物質に添加されているオイルが正極から溶出したＳｂの負極への析出を抑制する効果を有していることを見出し、本発明はその知見に基づくものである。その添加量は、０．３質量％より少なくなるとオイルのＳｂを補足する機能が十分でなく、０．７質量％より多くなると、オイルが負極板表面を覆う形になり負極板の性能が低下し好ましくないことがわかった。したがって、０．３質量％以上、０．７質量％以下が適当である。
【００１４】
なお、ここでのオイルとは石油（原油）を生成して得たオイルのことを意味する。本願の発明者は、種々のオイルについて試験した結果、特に鎖状構造のパラフィン系炭化水素のオイルが本発明の目的に効果的であることを見出した。
【００１５】
また、負極活物質とは、金属鉛と添加剤として含有される有機添加剤、ＢａＳＯ_４、カーボンからなるものをいう。
【００１６】
請求項２によれば、請求項１に記載の製造方法によって製造されたことを特徴とする鉛蓄電池である。
【００１７】
請求項３によれば、Ｓｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子を有する鉛蓄電池において、
正極格子質量（ｇ）／正極活物質質量（ｇ）が０．５〜１．２であり、かつ、正極活物質中に含まれるＳｎ量をＴ（質量％）、正極格子中に含まれるＳｂ量をＳ（質量％）としたとき、
１．５＞Ｔ≧０．１５×Ｓ＋０．０５であることを特徴とするものである。
【００１８】
本願の発明者は、上記Ｓｂの弊害を抑制する機能を有している物質としてＳｎを見出した。すなわち、正極活物質にＳｎが含まれていると正極格子から溶出したＳｂとＳｎとがＳｂ―Ｓｎ化合物を生成し、Ｓｂが正極活物質内に留まり、負極に析出するのを抑制する効果があることがわかった。
【００１９】
Ｓｎの適切な添加量は、正極格子に含まれるＳｂ量に関係しており、正極格子内に含まれるＳｂ量をＳ（質量％）、正極活物質内に含まれるＳｎ量をＴ（質量％）とした時に
１．５＞Ｔ≧０．１５×Ｓ＋０．０５の関係を維持することによって、Ｓｎが有効に作用し、Ｓｂの溶出を抑制することが分かった。すなわち、Ｓｎ量としては最大でも正極格子中に含まれる最大Ｓｂ量１．５質量％より少ない質量％に抑える必要がある。Ｓｎ量が１．５％以上になるとＳｂの存在に関係なくＳｎの弊害が現れ、蓄電池の性能が低下する。また、添加量の下限値は正極格子中のＳｂ濃度に関係し、試験結果からＴ≧０．１５×Ｓ＋０．０５の関係を維持する必要があることがわかった。
【００２０】
上記関係は、正極格子質量（ｇ）／正極活物質量（ｇ）が０．５〜１．２の範囲において有効に機能することもわかった。
【００２１】
請求項４によれば、Ｓｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子を有する鉛蓄電池において
正極活物質量に対する負極活物質量の比率をセル当たり、０．６以上に保つことを特徴とするものである。
【００２２】
請求項１および３の発明は、制御弁式鉛蓄電池において、正極格子から溶出したＳｂが負極に析出するのを抑制する働きをするものであったが、本発明は、負極板がＳｂの弊害を受けた時にその劣化速度をできるだけ遅くし、蓄電池の長寿命化を図ろうとするもので、通常は正極活物質量に対する負極活物質量の比率が低く設定されているのに対して、セル当たり０．６以上を確保するものである。
【００２３】
なお、ここでのセル当たりの正極活物質量に対する負極活物質量の比率は、正極活物質であるＰｂＯ_２と負極活物質であるＰｂおよび各種添加剤を含んだ質量比をいう。
【００２４】
請求項５によれば、請求項２および３に記載の鉛蓄電池である。
【００２５】
負極活物質に添加したオイルと正極活物質に添加したＳｎとの相乗効果によりＳｂの弊害がさらに抑制でき長寿命化が図れる。
【００２６】
請求項６によれば、請求項２および４に記載の鉛蓄電池である。
【００２７】
負極活物質に添加したオイルおよび負極活物質量／正極活物質量を０．６以上にする方法との相乗効果によりＳｂの弊害がさらに抑制でき長寿命化が図れる。
【００２８】
請求項７によれば、請求項３および４に記載の鉛蓄電池である。
【００２９】
正極活物質中に添加したＳｎとセル当たりの負極活物質量／正極活物質量を０．６以上にする方法との相乗効果によりＳｂに弊害がさらに抑制でき長寿命化が図れる。
【００３０】
請求項８によれば、請求項２、３および４に記載の鉛蓄電池である。
【００３１】
負極活物質に添加したオイル、正極活物質に添加したＳｎおよびセル当たりの負極活物質量／正極活物質量を０．６以上にする方法との相乗効果により、Ｓｂの弊害がさらに抑制でき一層の長寿命化が図れる。
【００３２】
請求項９によれば、負極活物質中に負極活物質量に対して０．３質量％以上、０．８質量％以下のリグニンを添加したことを特徴とするものである。
【００３３】
本願の発明者は、制御弁式鉛蓄電池におけるＳｂの弊害を抑制する他の要素として負極活物質に添加されているリグニンもその機能を有していることを見出した。すなわち、正極から溶出してきたＳｂが負極に析出した場合に、該リグニンがＳｂを捕捉してくれるので、Ｓｂの弊害が抑制されることが分かった。しかし、リグニン量が０．８質量％より多いとリグニンが負極板表面を覆ってしまい、負極板の性能劣化をもたらす。一方、０．３質量％より少ないとＳｂを捕捉する能力が低下し、その効果が得られない。したがって、０．３〜０．８質量％の範囲が好ましいことがわかった。
【００３４】
なお、ここでのリグニンの量は、紫外線吸収スペクトル法で測定した値を言う。
【００３５】
請求項１０によれば、正極活物質密度が３．１ｇ／ｃｍ^３以上、３．８ｇ／ｃｍ^３以下であることを特徴とするものである。
【００３６】
請求項１〜９の発明は、Ｓｂが負極に析出することにより負極板が劣化するのを抑制する方策に関するものであったのに対して、本発明は、Ｓｂが正極活物質同士の結合力を高める機能を有していることにより、低密度の正極活物質を用いても、優れたサイクル寿命性能が得られるというものである。
【００３７】
周知のとおり、正極活物質は多孔性の物質であり、多孔度が高い、すなわち、低密度な活物質は、活物質内に空隙が多く存在し硫酸との反応性が良く、正極活物質の利用率が上昇する。その反面、活物質同士の結合力が弱くなるのでサイクル寿命性能の劣る欠点を有していた。これに対して、Ｓｂが正極活物質同士の結合力を高める機能を有していることがわかった。したがって、３．１ｇ／ｃｍ^３以上、３．８ｇ／ｃｍ^３以下の低密度な活物質でも容量が優れ、しかもサイクル使用においても寿命の優れた蓄電池の得られることが分かった。
【００３８】
【実施例】
まず、参考例として、上述したようにＳｂ濃度が０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金を正極格子に使用することにより、正極格子にＳｂを含まない制御弁式鉛蓄電池に比べて、優れたサイクル寿命性能を有していることを明らかにするために行った試験結果について述べる。その際、使用する電解液の比重の寿命性能に及ぼす影響についても併せ試験を行った。
【００３９】
正極格子中のＳｂ量がゼロを含む６種類のＰｂ−Ｓｂ合金からなる鋳造格子を作製し、該格子に通常のペーストを充填・乾燥して、正極板を作製した。負極板には、Ｐｂ−０．０７質量％Ｃａ−１．３質量％Ｓｎ合金の鋳造格子を用い、該格子に通常のペーストを充填・乾燥を行い、作製したものを用いた。これら正極板３枚、負極板４枚を微細ガラス繊維セパレータを介して交互に積層し、電槽に挿入し、最終比重が１．２５〜１．４４になるような濃度の希硫酸を所定量注液後、電槽内で化成を行い、通常の制御弁を装着した定格容量、約７Ａｈ（２０ｈＲ）、公称電圧、１２Ｖの制御弁式鉛蓄電池を製作した。なお、本実施例では、負極活物質中のオイル量は０質量％、正極活物質中のＳｎ量は０質量％、負極活物質中のリグニン量は０．３質量％、セルあたりの負極活物質量／正極活物質量は０．８、正極活物質密度は３．２ｇ／ｃｍ^３を適用した。
【００４０】
上記蓄電池を下記の条件でサイクル寿命試験を行った。
（サイクル寿命試験条件）
放電：１．７５Ａ（０．２５ＣＡ）、放電終止電圧：１．７Ｖ／セル
充電：最大電流１．４Ａ（０．２ＣＡ）で充電を行い、蓄電池電圧が２．４Ｖ／セルに到達した時点で、０．３５Ａ（０．０５ＣＡ）の定電流充電に切り替え、放電量の１１０％の充電を行った。
試験雰囲気温度：２５℃
約１００サイクル毎に、上記放電条件で容量の確認を行った。蓄電池の容量が初期の５０％に低下した時点を寿命とした。
【００４１】
なお、この試験では、オイルの添加量、０質量％、Ｓｎの添加量、０質量％、負極活物質量／正極活物質量、０．８、正極活物質密度、３．２ｇ／ｃｍ^３をそれぞれ適用した。
【００４２】
試験結果を図１に示す。
【００４３】
図１に示すように、正極格子内のＳｂ量が０．５から１．５質量％の範囲の蓄電池は、約６７０〜８００サイクルの寿命を示したのに対して、２質量％の蓄電池は４００サイクル以下に低下した。この理由は、Ｓｂ量が多く、負極板に析出し、負極板が早期に劣化したためである。一方、０．３質量％の蓄電池は、Ｓｂの効果が現れず、Ｓｂ量が０質量％の格子を用いた蓄電池と同様の特性を示し、短寿命になった。
【００４４】
蓄電池に用いる電解液濃度（比重）に関しては、１．２９より低くなると、短寿命になった。その理由は、電解液比重が低いと、希硫酸中のＳｂの溶解度が増加し、負極板に析出する量が多くなり、負極板を劣化させたためである。一方、電解液比重が１．４より高くなった場合も短寿命になった。これは、高比重により正極活物質が軟化・脱落したためである。
【００４５】
以上のように、制御弁式鉛蓄電池において、サイクル使用における短寿命を改善するためにＳｂを含有する正極格子を用いる場合に、該Ｓｂ量は０．５〜１．５質量％の範囲が好ましいことがわかる。また、電解液比重は、１．２９以上を用いるのがＳｂの溶出の抑制に有効であるが、比重が高くなりすぎると正極活物質の軟化が起こるので１．４が限度といえる。
【００４６】
次に、本発明の効果を明確にするために実施例に基づき詳細に説明する。
（実施例１）
実施例１では、負極活物質に添加されているオイルが正極格子から溶出したＳｂの負極板への析出を抑制する機能を有していることを明確にするために行った試験結果について述べる。
【００４７】
正極格子中のＳｂ量がゼロを含み６種類の正極板を作成し、これらと負極活物質中のオイルの添加量がゼロを含めて８種類の極板とを組み合わせて、それ以外は、参考例と同じ処方により定格容量約７Ａｈ、公称電圧１２Ｖの制御弁式鉛蓄電池を作製した。オイルには、鎖状構造のパラフィン系炭化水素をベースにしたオイルを使用した。また、電解液比重は、１．３２（２０℃）、正極活物質中のＳｎ量は０質量％、負極活物質中のリグニン量は０．３質量％、セルあたりの負極活物質量／正極活物質量は０．８、正極活物質密度は３．２ｇ／ｃｍ^３をそれぞれ適用した。
【００４８】
上記、蓄電池を参考例と同じ条件による、サイクル寿命試験を行った。その結果を図２に示す。
【００４９】
図２に示すように、正極格子中のＳｂ量が０．５から１．５質量％の範囲で、オイル量が０質量％の蓄電池のサイクル寿命が約７００サイクルであったのに対して、オイル添加量が０．３質量％以上、０．７質量％の蓄電池が８００〜１０００サイクルの寿命を示し、オイルの効果が認められた。しかし、０．８質量％では寿命が低下していた。その理由は、オイルが多すぎて負極板表面を覆う形になり、負極板が十分に機能しなかったためと考えられる。Ｓｂ量が２．０質量％の蓄電池は、Ｓｂの弊害が大きく、オイルの添加量に関係なく負極板が劣化し、寿命になった。一方、Ｓｂ量が０あるいは０．３質量％の蓄電池では、オイルの量に関係なくＳｂがその機能が十分でないかあるいは全くないことにより正極板の劣化により短寿命になった。
【００５０】
以上のように、負極活物質中に０．３質量％以上、０．７質量％以下のオイルを添加することによって、該オイルが正極板から溶出してきたＳｂが負極に析出するのを抑制し、負極の劣化を防止し、寿命性能が改善されることがわかった
（実施例２）
実施例２では、正極活物質中にＳｎが存在すると、正極格子から溶出してきたＳｂと化合物を形成し、Ｓｂが電解液中に溶出するのを抑制する効果を有していることを明らかにするために行った試験結果についてのべる。
【００５１】
正極格子中のＳｂ量がゼロを含み６種類の正極板を作成し、これら極板と、正極活物質中のＳｎの添加量がゼロを含めて９種類の極板とを組み合せて、それ以外は、参考例と同じ処方により、定格容量約７Ａｈ、公称電圧１２Ｖの制御弁式鉛蓄電池を作製した。なお、正極格子質量（ｇ）／正極活物質量（ｇ）は１．０に設定した。
【００５２】
この場合、オイル量は、０．３質量％、電解液比重は、１．３２（２０℃）、セルあたりの負極活物質量／正極活物質量は０．８、正極活物質密度は３．２ｇ／ｃｍ^３をそれぞれ適用した。
【００５３】
上記、蓄電池を参考例と同じ条件による、サイクル寿命試験を行った。その結果を図３に示す。
【００５４】
図３に示すように、正極格子中のＳｂ量が１．０質量％から１．５質量％の範囲の蓄電池で、正極活物質中のＳｎ量が１．５＞Ｔ（Ｓｎ質量％）≧０．１５×Ｓ（Ｓｂ質量％）＋０．０５を満足する範囲においては、Ｓｎの効果が有効に機能し、負極活物質に添加されたオイルの効果とが相まって、１０００サイクル以上の優れた寿命性能を示した。本処方では、Ｓｂの弊害を抑制する効果が大きく、サイクル寿命性能が大幅に改善されたので、Ｓｂ量０．５質量％の蓄電池は、Ｓｂが少ないためのサイクル寿命における負の効果が現れ、正極板の劣化により約９００サイクルに留まった。
【００５５】
Ｓｎ量の影響に関しては、１．５質量％以上になると、正極格子中のＳｂ量にかかわりなく、サイクル寿命が大幅に低下した。これは、Ｓｎの量が多いと正極とＳｎとの間で局部電池が形成され、自己放電が大きくなったためと考えられる。
【００５６】
また、正極格子中のＳｂ量が２．０質量％になるとＳｎの効果よりも、Ｓｂの弊害が上回り、短寿命であった。
【００５７】
本実施例では、オイルの添加量は、０．３質量％に固定したが、添加量０．３〜０．７質量％の範囲で同様のサイクル寿命傾向が得られた。
【００５８】
また、正極格子質量（ｇ）／正極活物質質量（ｇ）０．５〜１．２の範囲において、Ｓｎが有効に作用することを他の試験で確認した。
（実施例３）
実施例３では、負極板に添加されているリグニンの量を多くすると、正極板から溶出してきたＳｂを捕捉し、該Ｓｂが負極板に及ぼす弊害を抑制する機能を有していることを明確にするために行った試験結果について述べる。
【００５９】
正極格子中のＳｂ量がゼロを含み６種類の正極板を作製し、これら極板と負極活物質中のリグニンの量が異なる６種類の極板とを組み合わせ、それ以外は参考例と同じ処方により定格容量約７Ａｈ、公称電圧１２Ｖの制御弁式鉛蓄電池を作製した。
【００６０】
この場合、オイルの添加量は、０．３質量％、正極活物質中のＳｎ量は、０質量％、電解液比重は、１．３２（２０℃）、セルあたりの負極活物質量／正極活物質量は０．８、正極活物質密度は３．２ｇ／ｃｍ^３をそれぞれ適用した。
【００６１】
上記、蓄電池を参考例と同じ条件による、サイクル寿命試験を行った。その結果を図４に示す。
【００６２】
図４に示すように、正極格子中のＳｂ量が０．５〜１．５質量％で、負極板中のリグニン量が０．３〜０．８質量％である蓄電池は良好なサイクル寿命性能を示した。リグニン量が０．８質量％より多くなるとリグニンが負極板表面を覆ってしまい負極板が本来の機能をしなくなり、サイクル寿命は急激に低下した。リグニンの添加量が０．３質量％より少なくなると、リグニンのＳｂ捕捉機能が低下し、正極中のＳｂ量に関係なくサイクル寿命が悪かった。
【００６３】
また、正極格子中のＳｂ量が２質量％になると、リグニンの効果よりもＳｂの弊害が上回り短寿命であった。
【００６４】
本実施例では、負極活物質中のオイル量は、０．３質量％、正極活物質中のＳｎ量は、０質量％にそれぞれ固定したが、オイルの添加量、０．２質量％以上、０．７質量％以下、正極活物質中のＳｎ量、１．５＞Ｔ（Ｓｎの質量％）≧０．１５×Ｓ（Ｓｂの質量％）＋０．０５が適用される範囲において、それぞれ単独あるいは組み合わせて適用しても同様の寿命傾向が得られた。
（実施例４）
実施例４では、正極格子中にＳｂを含有する制御弁式鉛蓄電池において、正極活物質量に対する負極活物質量の比率を変えた場合の、Ｓｂの負極に及ぼす弊害の程度を調べる試験を行った結果について述べる。
【００６５】
正極活物質量が一定であって、正極格子中のＳｂ量がゼロを含み６種類の正極板を作製し、前記正極活物質量に対する負極活物質量の比率が異なる５種類の負極板とを組み合わせて、それ以外は参考例と同じ処方により定格容量約７Ａｈ、公称電圧１２Ｖの制御弁式鉛蓄電池を作製した。
【００６６】
これらに対して、オイルの添加量は０．３質量％、正極活物質中のＳｎ量は０質量％、負極活物質中のリグニン量は負極原料に対して０．３質量％、電解液比重は、１．３２（２０℃）、正極活物質密度は３．２ｇ／ｃｍ^３をそれぞれ適用した。
【００６７】
上記、蓄電池を参考例と同じ条件によるサイクル寿命試験を行った。その結果を図５に示す。
【００６８】
図５に示すように、正極格子中のＳｂ量が０．５〜１．５質量％の範囲の蓄電池では、負極活物質量／正極活物質量が０．６以上であれば、良好なサイクル寿命を示したが、０．６より小さくなると、良好なサイクル寿命を示していたＳｂ量範囲０．５〜１．５質量％であっても、負極が早期に劣化するために短寿命になった。Ｓｂ量が２．０質量％の蓄電池は、Ｓｂの弊害が大きいために、負極活物質量／正極活物質量が０．６以上であってもサイクル寿命性能は改善されなかった。
【００６９】
本実施例では、オイルの添加量は、０．３質量％、正極活物質中のＳｎ量は、０質量％、負極活物質中のリグニン量は、０．３質量％に固定した例について説明したが、オイルの添加量、０．２質量％以上、０．７質量％以下、正極活物質中のＳｎ量、１．５＞Ｔ≧０．１５×Ｓ＋０．０５の適用される範囲、負極活物質中のリグニン量、０．３質量％以上、０．８質量％以下について、それぞれ単独あるいは組み合わせて適用した場合、同様の寿命性能の傾向が得られた。
（実施例５）
周知のとおり、正極板に低密度の活物質を適用すると、正極活物質の利用率が改善され、容量が増加するが、活物質間の結合力が弱いために短寿命の傾向にあったが、正極格子中にＳｂを含有していると該Ｓｂが正極活物質同士の結合力を高める機能を有しており、初期性能が良く、しかも寿命性能の優れた制御弁式鉛蓄電池が得られることを明らかにするために行った試験結果について述べる。
【００７０】
正極格子中のＳｂ量がゼロを含み６種類の正極格子と活物質密度の異なる７種類の正極板とを組み合わせた蓄電池を作製した。オイルの添加量は、０質量％、正極活物質中のＳｎ量は、０質量％、負極活物質中のリグニン量は、０．３質量％、電解液比重は１．３２（２０℃）、セル当たりの負極活物質量／正極活物質量は０．８をそれぞれ適用した。
【００７１】
上記蓄電池の初期容量の評価および参考例と同じ条件によるサイクル寿命試験を行った。その結果を図６および図７にそれぞれ示す。
【００７２】
図６に示すように、Ｓｂ濃度が０および０．３質量％の蓄電池は、正極活物質量の密度が３．３ｇ／ｃｍ^３以下になると容量が低下したのに対して、Ｓｂ濃度０．５質量％以上では、正極活物質の結合力が高められ、３．１ｇ／ｃｍ^３といった低密度の正極活物質でも優れた容量を示した。しかし、正極活物質密度が３ｇ／ｃｍ^３になるとＳｂ濃度が０．５質量％以上でも容量低下は避けられなかった。
【００７３】
図７は、上記蓄電池をサイクル寿命試験に供した結果を示す。上述したように正極活物質密度３ｇ／ｃｍ^３の蓄電池は初期から容量が低かったので試験には供しなかった。
【００７４】
図７に示すように、Ｓｂ量がゼロあるいは０．３質量％の蓄電池は、正極活物質密度が３．５ｇ／ｃｍ^３になるとサイクル寿命性能が低下してきたのに対して、Ｓｂ量０．５〜１．５質量％の蓄電池は３．１ｇ／ｃｍ^３でも優れたサイクル寿命性能を有していた。
【００７５】
しかし、Ｓｂ量２．０質量％の蓄電池は上述したと同じ理由でＳｂの弊害により短寿命であった。
【００７６】
一方、Ｓｂ量、０および０．３％の蓄電池は、正極活物質が低密度では短寿命であったが、３．８ｇ／ｃｍ^３以上になるとサイクル寿命性能がよくなった。これは高密度によって活物質同士の結合力がよくなったことが原因していると考えられる。
【００７７】
本実施例では、負極活物質中のオイルの添加量は、０質量％、正極活物質中のＳｎ量は、０質量％、負極活物質中のリグニン量は、０．３質量％、セルあたりの負極活物質量／正極活物質量は０．８にそれぞれ固定した場合について説明したが、オイル添加量、０．２質量％以上、０．７質量％以下、Ｓｎ添加量とＳｂ量との関係１．５＞Ｔ≧０．１５×Ｓ＋０．０５が適用される範囲〔正極格子質量（ｇ）／正極活物質質量（ｇ）：１．０〕、リグニン量、０．３質量％以上、０．８質量％以下、セル当たりの負極活物質量／正極活物質量０．６以上についてそれぞれ単独あるいはこれらの組み合わせを適用した場合にも同様の寿命性能傾向が得られた。
【００７８】
なお、実施例においておいては、制御弁式鉛蓄電池について説明したが、Ｓｂ濃度０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金からなる正極格子とＰｂ、Ｐｂ−ＣａあるいはＰｂ−Ｃａ−Ｓｎ合金からなる負極格子とを有する鉛蓄電池で、電解液が十分に存在する開放型の鉛蓄電池においても、オイル添加量、０．２質量％以上、０．７質量％以下、正極活物質中のＳｎ添加量と正極格子中のＳｂ量との関係１．５＞Ｔ≧０．１５×Ｓ＋０．０５の適用される範囲、負極活物質中のリグニン量、０．３質量％以上、０．８質量％以下、セル当たりの負極活物質量／正極活物質量０．６以上、正極活物質密度が３．１ｇ／ｃｍ^３以上、３．８ｇ／ｃｍ^３以下を適用することによって絶対値は異なるが制御弁式鉛蓄電池と同様の効果が得られるのを確認した。
【００７９】
【発明の効果】
正・負極格子にＳｂを含まない正・負極板を用いた鉛蓄電池では、サイクル使用において充・放電条件によっては早期容量低下が発生する。その対策として正極格子にＳｂ濃度０．５質量％以上、１．５質量％以下のＰｂ−Ｓｂ系合金を用いることによって上記問題は解消されるが、該Ｓｂが電解液中に溶出し、負極に析出すると負極の水素過電圧を下げ、水素ガスが発生し、制御弁式鉛蓄電池の特徴である、密閉反応機能のバランスが崩れ、その機能を失うと共に、負極板の性能が劣化する問題を抱えていた。これに対して、負極活物質中にオイルを一定量添加する、正極活物質中にＳｎを一定量添加する、負極活物質中にリグニンを一定量添加するあるいは／およびセル当たりの負極活物質量／正極活物質量の比を０．６以上にすることによって上記、Ｓｂの弊害が抑制され、制御弁式鉛蓄電池あるいは開放型鉛蓄電池本来の優れたサイクル寿命性能が得られ、その工業的効果が極めて大である。
【図面の簡単な説明】
【図１】制御弁式鉛蓄電池における、正極格子中のＳｂ濃度および電解液比重とサイクル寿命との関係を示す図。
【図２】実施例１の負極活物質中のオイルの添加量（質量％）とサイクル寿命との関係を示す図。
【図３】実施例２の正極活物質中のＳｎ量（質量％）とサイクル寿命との関係を示す図。
【図４】実施例３の負極活物質中のリグニン量（質量％）とサイクル寿命との関係を示す図。
【図５】実施例４のセルあたりの負極活物質量（ｇ）／正極活物質量（ｇ）とサイクル寿命との関係を示す図。
【図６】実施例５の正極活物質密度と蓄電池容量との関係において、正極格子中のＳｂ量（質量％）の影響を示す図。
【図７】実施例５の正極活物質密度と蓄電池のサイクル寿命との関係において、正極格子中のＳｂ量（質量％）の影響を示す図。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lead storage battery and a method for manufacturing the same.
[0002]
[Prior art]
Among the lead storage batteries, the control valve type lead storage battery is characterized in that it has no leakage and no maintenance. The non-leakage liquid has a structure in which the electrolyte is impregnated and held only in the separator and has no flowing electrolyte, and has no electrolyte leakage even when the storage battery is placed horizontally. The term "no maintenance" refers to a characteristic in which no gas is generated during normal charging due to the sealed reaction function which is a feature of the storage battery, the electrolyte is hardly reduced, and maintenance such as replacement is not necessary.
[0003]
Because of these excellent characteristics, the use of control valve type lead-acid batteries has been expanding in various fields in recent years. Accordingly, demands for high reliability, high energy density, and long life have been increasing.
[0004]
The sealed reaction in the above-described control valve type lead-acid battery is represented by the following equations (1), (2) and (3).
(Positive electrode) H₂O = 1 / 2O₂+ 2H⁺+ 2e⁻... (1)
(Negative electrode) Pb + 1 / 2O₂+ 2H⁺+ SO₄ ^2-= PbSO₄+ H₂O ... (2)
PbSO₄+ 2e⁻= Pb + SO₄ ^2-・・・・・・・・・・ (3)
As described above, water (H₂O) is decomposed and oxygen gas (O₂) Occurs. However, as described above, the storage battery has a structure in which the electrolyte is impregnated and held only in the separator and no fluid electrolyte is present.₂Easily penetrates through the separator to the negative electrode, reacts with Pb and reacts with PbSO₄And H₂O is generated. That is, H lost in equation (1)₂O has been regenerated by equation (2), and the electrolyte does not decrease as a whole.
[0005]
Also, the PbSO generated by equation (2)₄Is reduced to Pb by the charge reaction of the negative electrode as shown in the equation (3), and the negative electrode is charged with hydrogen gas (H₂) Does not occur. That is. Neither oxygen gas nor hydrogen gas is generated during charging.
[0006]
However, when the self-discharge of the negative electrode increases, extra hydrogen gas is generated, and H gas according to the above equations (1), (2) and (3) is used.₂If the balance of the regeneration cycle of O is lost and the negative electrode becomes insufficiently charged, and if this continues, the negative electrode becomes PbSO4.₄A so-called "sulfation phenomenon" occurs, which makes it impossible to charge the battery, resulting in a short life.
[0007]
Therefore, in the control valve type lead-acid battery, Pb, Pb-Ca alloy or Pb-Ca-Sn alloy, which has a small amount of self-discharge, is usually adopted for the positive / negative grid.
[0008]
However, although the above grid is used while continuously charging, there is no problem in trickle or float use, the use of a cycle where charge and discharge are constantly repeated, especially in the use state where the amount of discharge is small and overcharged, is used for the positive grid. Since the oxidation progresses excessively, the portion is preferentially discharged at the time of discharge, an insulating layer of lead sulfate is formed at the interface between the positive electrode grid and the active material, and the capacity is rapidly reduced (early capacity reduction and Premature Capacity Loss). (Also referred to as PCL for short).
[0009]
Regarding the above-mentioned early capacity reduction, not only the control valve type lead-acid battery, but also a Pb, Pb-Ca or Pb-Ca-Sn alloy lattice containing no Sb for the positive and negative electrodes, and an open type battery in which the electrolyte is sufficiently present Similar phenomena are observed in lead-acid batteries.
[0010]
As one of the above measures, Pb, Pb-Ca alloy or Pb-Ca-Sn alloy is used for the negative electrode grid, and the Sb concentration is 0.5% by mass or more and 1.5% by mass or less for the positive electrode. A method using a Pb-Sb-based alloy lattice having a low concentration (referred to as low antimony) has been proposed. Due to the presence of Sb in the positive electrode, although the cause is not clear, the above-mentioned early capacity reduction in cycle use does not occur. However, when the Sb elutes from the positive electrode into the electrolytic solution and precipitates on the negative electrode, the hydrogen overvoltage of the negative electrode is reduced, the generation of hydrogen gas is promoted, the above-mentioned closed reaction cycle is out of balance, and the function of the control valve type lead storage battery is reduced. Loss of the negative electrode plate causes insufficient charging, and the performance of the storage battery deteriorates. Also in the open type storage battery, there is a problem that the charging efficiency is lowered due to the reduction of the hydrogen overvoltage, the reduction of the electrolyte is accelerated, and the performance is deteriorated.
[0011]
[Problems to be solved by the invention]
In a lead-acid battery having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less, the presence of Sb prevents an early decrease in capacity and prevents Sb from forming on the negative electrode. It is an object of the present invention to provide a method of manufacturing a lead storage battery and a lead storage battery having excellent cycle life while suppressing the adverse effects as much as possible.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a method for manufacturing a lead-acid battery having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less. ,
It is characterized in that 0.3% by mass or more and 0.7% by mass or less of oil are added to the negative electrode active material based on the amount of the negative electrode active material.
[0013]
In a lead-acid battery, particularly a control valve-type lead-acid battery, when a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less is used for a positive electrode grid, the cycle of the battery is determined by the presence of Sb. Although the early capacity reduction during use can be suppressed, Sb elutes in the electrolyte and precipitates on the negative electrode, lowering the hydrogen overvoltage, promoting the generation of hydrogen gas, disrupting the balance of the above-described closed reaction cycle, and charging the negative electrode plate. There was a problem of shortage, which led to sulfation and accelerated deterioration of storage battery performance. As one of means for suppressing the adverse effects of Sb, the present inventors have found that oil added to the negative electrode active material has an effect of suppressing the precipitation of Sb eluted from the positive electrode on the negative electrode. It is based on. If the addition amount is less than 0.3% by mass, the function of supplementing the Sb of the oil is not sufficient, and if it exceeds 0.7% by mass, the oil covers the surface of the negative electrode plate, and the performance of the negative electrode plate deteriorates. It was found to be undesirable. Therefore, it is appropriate that the content is 0.3% by mass or more and 0.7% by mass or less.
[0014]
Here, the oil means an oil obtained by producing petroleum (crude oil). As a result of testing various oils, the inventors of the present application have found that a paraffinic hydrocarbon oil having a chain structure is particularly effective for the purpose of the present invention.
[0015]
Further, the negative electrode active material is an organic additive contained as metallic lead and an additive, BaSO₄, Carbon.
[0016]
According to a second aspect, there is provided a lead storage battery manufactured by the manufacturing method according to the first aspect.
[0017]
According to claim 3, a lead-acid battery having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less,
The mass of the positive electrode lattice (g) / the mass of the positive electrode active material (g) is 0.5 to 1.2, the amount of Sn contained in the positive electrode active material is T (% by mass), and the amount of Sb contained in the positive electrode lattice is When the amount is S (% by mass),
1.5> T ≧ 0.15 × S + 0.05.
[0018]
The inventor of the present application has found Sn as a substance having a function of suppressing the adverse effects of Sb. That is, when Sn is contained in the positive electrode active material, Sb and Sn eluted from the positive electrode lattice generate an Sb-Sn compound, and the effect of suppressing Sb from remaining in the positive electrode active material and depositing on the negative electrode is obtained. I found it.
[0019]
The appropriate amount of Sn added is related to the amount of Sb contained in the positive electrode lattice, and the amount of Sb contained in the positive electrode lattice is S (% by mass), and the amount of Sn contained in the positive electrode active material is T (% by mass). )
By maintaining the relationship of 1.5> T ≧ 0.15 × S + 0.05, it was found that Sn worked effectively and suppressed the elution of Sb. That is, it is necessary to suppress the maximum amount of Sn to less than 1.5% by mass of the maximum amount of Sb contained in the positive electrode lattice. When the amount of Sn is 1.5% or more, adverse effects of Sn appear regardless of the presence of Sb, and the performance of the storage battery is reduced. Further, the lower limit of the addition amount was related to the Sb concentration in the positive electrode lattice, and it was found from the test results that it was necessary to maintain the relationship of T ≧ 0.15 × S + 0.05.
[0020]
The above relationship was found to work effectively when the mass of the positive electrode lattice (g) / the amount of the positive electrode active material (g) was in the range of 0.5 to 1.2.
[0021]
According to claim 4, in a lead-acid battery having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less.
The ratio of the amount of the negative electrode active material to the amount of the positive electrode active material is maintained at 0.6 or more per cell.
[0022]
The first and third aspects of the present invention have the function of suppressing the deposition of Sb eluted from the positive electrode grid on the negative electrode in a control valve type lead-acid battery. In order to prolong the service life of the storage battery, the ratio of the amount of the negative electrode active material to the amount of the positive electrode active material is set to be low. 0.6 or more is secured.
[0023]
Here, the ratio of the amount of the negative electrode active material to the amount of the positive electrode active material per cell is PbO which is the positive electrode active material.₂And the mass ratio including Pb as the negative electrode active material and various additives.
[0024]
According to claim 5, there is provided a lead storage battery according to claims 2 and 3.
[0025]
The synergistic effect of the oil added to the negative electrode active material and the Sn added to the positive electrode active material further suppresses the adverse effects of Sb, thereby extending the life.
[0026]
According to claim 6, there is provided a lead storage battery according to claims 2 and 4.
[0027]
The adverse effect of Sb can be further suppressed by the synergistic effect with the method of setting the amount of the oil added to the negative electrode active material and the amount of the negative electrode active material / the amount of the positive electrode active material to 0.6 or more, and the life can be extended.
[0028]
According to claim 7, a lead storage battery according to claims 3 and 4.
[0029]
The synergistic effect of Sn added to the positive electrode active material and the method of setting the amount of the negative electrode active material / the amount of the positive electrode active material per cell to 0.6 or more can further suppress the adverse effect on Sb and extend the life.
[0030]
According to claim 8, there is provided a lead storage battery according to claims 2, 3 and 4.
[0031]
Oil added to the negative electrode active material, Sn added to the positive electrode active material, and the synergistic effect with the method of setting the amount of the negative electrode active material / the amount of the positive electrode active material per cell to 0.6 or more can further suppress the adverse effects of Sb. Life can be extended.
[0032]
According to a ninth aspect, lignin is added to the negative electrode active material in an amount of 0.3% by mass or more and 0.8% by mass or less based on the amount of the negative electrode active material.
[0033]
The inventor of the present application has found that lignin added to a negative electrode active material has another function as another element for suppressing the adverse effect of Sb in a control valve type lead-acid battery. That is, it was found that when Sb eluted from the positive electrode was deposited on the negative electrode, the lignin trapped Sb, so that the adverse effects of Sb were suppressed. However, when the lignin content is more than 0.8% by mass, the lignin covers the surface of the negative electrode plate, thereby deteriorating the performance of the negative electrode plate. On the other hand, if it is less than 0.3% by mass, the ability to trap Sb is reduced, and the effect cannot be obtained. Therefore, it turned out that the range of 0.3-0.8 mass% is preferable.
[0034]
Here, the amount of lignin refers to a value measured by an ultraviolet absorption spectrum method.
[0035]
According to claim 10, the positive electrode active material density is 3.1 g / cm.³3.8 g / cm³It is characterized by the following.
[0036]
The inventions of claims 1 to 9 relate to a measure for suppressing the deterioration of the negative electrode plate due to the precipitation of Sb on the negative electrode. Has a function of improving the cycle life even if a low-density positive electrode active material is used.
[0037]
As is well known, the positive electrode active material is a porous material, and the porosity is high, that is, a low-density active material has many voids in the active material and has good reactivity with sulfuric acid, Utilization increases. On the other hand, since the bonding force between the active materials is weakened, there is a disadvantage that the cycle life performance is inferior. On the other hand, it was found that Sb had a function of increasing the bonding force between the positive electrode active materials. Therefore, 3.1 g / cm³3.8 g / cm³It has been found that a storage battery having excellent capacity even with the following low-density active materials and having a long life even in cycle use can be obtained.
[0038]
【Example】
First, as a reference example, as described above, by using a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less for a positive electrode grid, a control valve containing no Sb in the positive electrode grid is used. The following describes the test results performed to clarify that the battery has superior cycle life performance as compared with the lead-acid battery. At that time, a test was also conducted on the effect of the specific gravity of the electrolyte used on the life performance.
[0039]
Cast grids composed of six kinds of Pb-Sb alloys including zero in the amount of Sb in the positive electrode grid were prepared, and the grid was filled with a normal paste and dried to prepare a positive electrode plate. For the negative electrode plate, a casting grid of a Pb-0.07 mass% Ca-1.3 mass% Sn alloy was used, and the grid was filled with a normal paste and dried, and then used. The three positive plates and the four negative plates are alternately laminated via a fine glass fiber separator, inserted into a battery case, and diluted sulfuric acid having a concentration such that the final specific gravity becomes 1.25 to 1.44 in a predetermined amount. After the injection, the battery was formed in a battery case, and a control valve type lead-acid battery having a rated capacity of about 7 Ah (20 hR), a nominal voltage of 12 V and a normal control valve was manufactured. In this example, the amount of oil in the anode active material was 0% by mass, the amount of Sn in the cathode active material was 0% by mass, the amount of lignin in the anode active material was 0.3% by mass, and the amount of anode active material per cell was 0.3% by mass. Material amount / positive electrode active material amount is 0.8, positive electrode active material density is 3.2 g / cm³Was applied.
[0040]
The above storage battery was subjected to a cycle life test under the following conditions.
(Cycle life test conditions)
Discharge: 1.75 A (0.25 CA), discharge end voltage: 1.7 V / cell
Charging: Charging was performed at a maximum current of 1.4 A (0.2 CA), and when the storage battery voltage reached 2.4 V / cell, switching to a constant current charging of 0.35 A (0.05 CA) was performed, and a discharge amount of 110 A % Charge.
Test atmosphere temperature: 25 ° C
The capacity was checked under the above-mentioned discharge conditions every about 100 cycles. The time when the capacity of the storage battery was reduced to 50% of the initial value was defined as the life.
[0041]
In this test, the amount of oil added, 0% by mass, the amount of Sn added, 0% by mass, negative electrode active material amount / positive electrode active material amount, 0.8, positive electrode active material density, 3.2 g / cm³Was applied respectively.
[0042]
The test results are shown in FIG.
[0043]
As shown in FIG. 1, a storage battery in which the amount of Sb in the positive electrode grid is in the range of 0.5 to 1.5 mass% exhibited a life of about 670 to 800 cycles, whereas a storage battery of 2 mass% It decreased to 400 cycles or less. The reason for this is that the amount of Sb was large and precipitated on the negative electrode plate, and the negative electrode plate deteriorated early. On the other hand, the storage battery of 0.3% by mass did not exhibit the effect of Sb, exhibited the same characteristics as the storage battery using the lattice having the Sb amount of 0% by mass, and had a short life.
[0044]
When the concentration (specific gravity) of the electrolyte used for the storage battery was lower than 1.29, the life was shortened. The reason is that when the specific gravity of the electrolyte solution is low, the solubility of Sb in dilute sulfuric acid increases, the amount of Sb deposited on the negative electrode plate increases, and the negative electrode plate is deteriorated. On the other hand, when the electrolyte specific gravity was higher than 1.4, the life was shortened. This is because the positive electrode active material was softened or dropped due to the high specific gravity.
[0045]
As described above, in the case of using the positive electrode grid containing Sb in the control valve type lead-acid battery to improve short life in cycle use, the amount of Sb is preferably in the range of 0.5 to 1.5% by mass. You can see that. The use of a specific gravity of 1.29 or more is effective for suppressing the elution of Sb, but if the specific gravity is too high, the positive electrode active material is softened.
[0046]
Next, in order to clarify the effects of the present invention, a detailed description will be given based on examples.
(Example 1)
Example 1 In Example 1, the results of a test performed to clarify that the oil added to the negative electrode active material has a function of suppressing the precipitation of Sb eluted from the positive electrode lattice on the negative electrode plate will be described.
[0047]
Six types of positive electrode plates were prepared, including the amount of Sb in the positive electrode lattice including zero, and these were combined with eight types of electrode plates including zero in the amount of oil added in the negative electrode active material. A control valve type lead-acid battery having a rated capacity of about 7 Ah and a nominal voltage of 12 V was manufactured according to the same recipe as in the example. As the oil, an oil based on a paraffinic hydrocarbon having a chain structure was used. The specific gravity of the electrolyte was 1.32 (20 ° C.), the amount of Sn in the positive electrode active material was 0% by mass, the amount of lignin in the negative electrode active material was 0.3% by mass, and the amount of negative electrode active material per cell / positive electrode The active material amount is 0.8 and the positive electrode active material density is 3.2 g / cm.³Was applied respectively.
[0048]
The storage battery was subjected to a cycle life test under the same conditions as in the reference example. The result is shown in FIG.
[0049]
As shown in FIG. 2, the cycle life of a storage battery having an Sb amount in the positive electrode grid of 0.5 to 1.5% by mass and an oil amount of 0% by mass was about 700 cycles, A storage battery having an oil addition amount of 0.3% by mass or more and 0.7% by mass exhibited a life of 800 to 1000 cycles, and the effect of the oil was recognized. However, at 0.8% by mass, the life was reduced. The reason is considered to be that the amount of oil was too large to cover the surface of the negative electrode plate, and the negative electrode plate did not function sufficiently. The storage battery having an Sb content of 2.0% by mass had a serious adverse effect of Sb, and the negative electrode plate was deteriorated regardless of the amount of added oil, and the life was shortened. On the other hand, in the storage battery having the Sb amount of 0 or 0.3% by mass, the function of Sb was insufficient or not at all irrespective of the amount of oil, so that the service life was shortened due to the deterioration of the positive electrode plate.
[0050]
As described above, by adding 0.3% by mass or more and 0.7% by mass or less of oil to the negative electrode active material, it is possible to prevent Sb eluted from the positive electrode plate from depositing on the negative electrode. It was found that preventing the deterioration of the negative electrode and improving the life performance
(Example 2)
Example 2 clearly shows that the presence of Sn in the positive electrode active material forms a compound with Sb eluted from the positive electrode lattice, and has the effect of suppressing the elution of Sb into the electrolyte. This section describes the results of the tests performed for
[0051]
Six types of positive plates were prepared including the amount of Sb in the positive electrode lattice including zero, and these plates were combined with nine types of positive plates including the amount of Sn added to the positive electrode active material including zero. Manufactured a control valve type lead-acid battery having a rated capacity of about 7 Ah and a nominal voltage of 12 V by the same prescription as that of the reference example. In addition, positive electrode lattice mass (g) / positive electrode active material amount (g) was set to 1.0.
[0052]
In this case, the amount of oil is 0.3% by mass, the specific gravity of the electrolyte is 1.32 (20 ° C.), the amount of the negative electrode active material / the amount of the positive electrode active material per cell is 0.8, and the density of the positive electrode active material is 3. 2g / cm³Was applied respectively.
[0053]
The storage battery was subjected to a cycle life test under the same conditions as in the reference example. The result is shown in FIG.
[0054]
As shown in FIG. 3, in a storage battery in which the amount of Sb in the positive electrode grid ranges from 1.0% by mass to 1.5% by mass, the amount of Sn in the positive electrode active material is 1.5> T (Sn% by mass) ≧ In a range satisfying 0.15 × S (Sb mass%) + 0.05, the effect of Sn functions effectively, and the effect of oil added to the negative electrode active material is combined to provide an excellent life of 1000 cycles or more. Performance was shown. In this formulation, the effect of suppressing the adverse effects of Sb is great, and the cycle life performance has been greatly improved. Therefore, a storage battery with an Sb content of 0.5% by mass has a negative effect on the cycle life due to the small amount of Sb, Due to the deterioration of the positive electrode plate, only about 900 cycles were maintained.
[0055]
Regarding the influence of the amount of Sn, when the amount was 1.5% by mass or more, the cycle life was significantly reduced irrespective of the amount of Sb in the positive electrode lattice. This is presumably because when the amount of Sn was large, a local battery was formed between the positive electrode and Sn and self-discharge increased.
[0056]
When the amount of Sb in the positive electrode grid was 2.0% by mass, the adverse effect of Sb exceeded the effect of Sn, and the life was short.
[0057]
In this example, the addition amount of the oil was fixed at 0.3% by mass, but the same cycle life tendency was obtained in the addition amount range of 0.3 to 0.7% by mass.
[0058]
In addition, it was confirmed by another test that Sn works effectively in the range of positive electrode lattice mass (g) / positive electrode active material mass (g) of 0.5 to 1.2.
(Example 3)
In Example 3, it was clarified that when the amount of lignin added to the negative electrode plate was increased, Sb eluted from the positive electrode plate was trapped, and the Sb had a function of suppressing the adverse effects on the negative electrode plate. The following describes the results of a test performed to achieve this.
[0059]
Six kinds of positive plates were prepared including the amount of Sb in the positive electrode lattice including zero, and these plates were combined with six types of plates having different amounts of lignin in the negative electrode active material. Produced a control valve type lead-acid battery having a rated capacity of about 7 Ah and a nominal voltage of 12 V.
[0060]
In this case, the amount of oil added was 0.3% by mass, the amount of Sn in the positive electrode active material was 0% by mass, the specific gravity of the electrolyte was 1.32 (20 ° C.), and the amount of negative electrode active material per cell / positive electrode The active material amount is 0.8 and the positive electrode active material density is 3.2 g / cm.³Was applied respectively.
[0061]
The storage battery was subjected to a cycle life test under the same conditions as in the reference example. The result is shown in FIG.
[0062]
As shown in FIG. 4, the storage battery in which the amount of Sb in the positive electrode grid is 0.5 to 1.5% by mass and the amount of lignin in the negative electrode plate is 0.3 to 0.8% by mass has good cycle life performance. showed that. When the lignin content was more than 0.8% by mass, the lignin covered the negative electrode plate surface, the negative electrode plate did not perform its original function, and the cycle life was rapidly reduced. When the amount of lignin added was less than 0.3% by mass, the Sb trapping function of lignin was reduced, and the cycle life was poor regardless of the amount of Sb in the positive electrode.
[0063]
When the amount of Sb in the positive electrode lattice was 2% by mass, the effect of Sb exceeded the effect of lignin, resulting in a short life.
[0064]
In this example, the amount of oil in the negative electrode active material was fixed at 0.3% by mass, and the amount of Sn in the positive electrode active material was fixed at 0% by mass. 0.7 mass% or less, the amount of Sn in the positive electrode active material, 1.5> T (mass% of Sn) ≧ 0.15 × S (mass% of Sb) +0.05 alone in the range where Alternatively, the same life tendency was obtained even when applied in combination.
(Example 4)
In Example 4, in a control valve type lead-acid battery containing Sb in the positive electrode grid, a test was conducted to examine the degree of adverse effects of Sb on the negative electrode when the ratio of the amount of the negative electrode active material to the amount of the positive electrode active material was changed. The results are described below.
[0065]
The amount of the positive electrode active material is constant, the amount of Sb in the positive electrode lattice is zero, and six types of positive electrode plates are produced. The five types of negative electrode plates having different ratios of the amount of the negative electrode active material to the amount of the positive electrode active material are prepared. Other than the above, a control valve type lead-acid battery having a rated capacity of about 7 Ah and a nominal voltage of 12 V was manufactured according to the same recipe as that of the reference example.
[0066]
On the other hand, the amount of the oil added was 0.3% by mass, the amount of Sn in the positive electrode active material was 0% by mass, the amount of lignin in the negative electrode active material was 0.3% by mass with respect to the negative electrode raw material, and the specific gravity of the electrolyte solution. Is 1.32 (20 ° C.), and the positive electrode active material density is 3.2 g / cm.³Was applied respectively.
[0067]
The storage battery was subjected to a cycle life test under the same conditions as in the reference example. The result is shown in FIG.
[0068]
As shown in FIG. 5, in the storage battery in which the amount of Sb in the positive electrode grid is in the range of 0.5 to 1.5% by mass, if the amount of the negative electrode active material / the amount of the positive electrode active material is 0.6 or more, a good cycle is obtained. Although the life was shown, if it was smaller than 0.6, the negative electrode was deteriorated early even if the Sb content range was 0.5 to 1.5% by mass, which showed a good cycle life, resulting in a short life. Was. Since the storage battery having an Sb content of 2.0% by mass had a large adverse effect of Sb, the cycle life performance was not improved even when the amount of the negative electrode active material / the amount of the positive electrode active material was 0.6 or more.
[0069]
In this embodiment, an example is described in which the amount of oil added is fixed at 0.3% by mass, the amount of Sn in the positive electrode active material is fixed at 0% by mass, and the amount of lignin in the negative electrode active material is fixed at 0.3% by mass. However, the amount of oil added, 0.2% by mass or more and 0.7% by mass or less, the amount of Sn in the positive electrode active material, the range of 1.5> T ≧ 0.15 × S + 0.05, the negative electrode When the lignin content in the active material was 0.3% by mass or more and 0.8% by mass or less and used alone or in combination, the same tendency of life performance was obtained.
(Example 5)
As is well known, when a low-density active material is applied to a positive electrode plate, the utilization rate of the positive electrode active material is improved, and the capacity is increased. When Sb is contained in the positive electrode grid, the Sb has a function of increasing the bonding force between the positive electrode active materials, so that a control valve type lead storage battery having good initial performance and excellent life performance can be obtained. The results of a test performed to clarify this will be described.
[0070]
A storage battery was produced by combining six types of positive electrode grids containing zero amount of Sb in the positive electrode grid and seven types of positive electrode plates having different active material densities. The amount of oil added was 0% by mass, the amount of Sn in the positive electrode active material was 0% by mass, the amount of lignin in the negative electrode active material was 0.3% by mass, the specific gravity of the electrolyte was 1.32 (20 ° C.), As the amount of the negative electrode active material / the amount of the positive electrode active material per cell, 0.8 was applied.
[0071]
The initial capacity of the storage battery was evaluated and a cycle life test was performed under the same conditions as in the reference example. The results are shown in FIGS. 6 and 7, respectively.
[0072]
As shown in FIG. 6, the storage batteries having Sb concentrations of 0 and 0.3% by mass have a positive electrode active material density of 3.3 g / cm 3.³When the Sb concentration was 0.5% by mass or more, the binding force of the positive electrode active material was increased, and the capacity decreased to 3.1 g / cm.³Even a low-density positive electrode active material showed excellent capacity. However, the positive electrode active material density is 3 g / cm.³, A decrease in capacity was inevitable even when the Sb concentration was 0.5% by mass or more.
[0073]
FIG. 7 shows the result of subjecting the storage battery to a cycle life test. As described above, the positive electrode active material density is 3 g / cm.³Was not subjected to the test because its capacity was low from the beginning.
[0074]
As shown in FIG. 7, the storage battery having zero or 0.3% by mass of Sb has a positive electrode active material density of 3.5 g / cm.³, The cycle life performance has decreased, whereas the storage battery with an Sb amount of 0.5 to 1.5 mass% has a capacity of 3.1 g / cm.³However, it had excellent cycle life performance.
[0075]
However, the storage battery having an Sb content of 2.0% by mass had a short life due to the adverse effect of Sb for the same reason as described above.
[0076]
On the other hand, the storage batteries with Sb contents of 0 and 0.3% had a short life at a low density of the positive electrode active material, but 3.8 g / cm.³Above, the cycle life performance was improved. This is considered to be due to the fact that the binding force between the active materials was improved by the high density.
[0077]
In this example, the amount of oil in the negative electrode active material was 0% by mass, the amount of Sn in the positive electrode active material was 0% by mass, the amount of lignin in the negative electrode active material was 0.3% by mass, and The case where the amount of the negative electrode active material / the amount of the positive electrode active material is fixed to 0.8 has been described, but the oil addition amount, 0.2% by mass or more and 0.7% by mass or less, the Sn addition amount and the Sb amount The relationship 1.5> T ≧ 0.15 × S + 0.05 is applied (positive electrode lattice mass (g) / positive electrode active material mass (g): 1.0), lignin amount, 0.3 mass% or more, The same life performance tendency was obtained when 0.8% by mass or less and the amount of the negative electrode active material per cell / the amount of the positive electrode active material of 0.6 or more were used alone or in combination.
[0078]
In the embodiment, the control valve type lead-acid battery has been described. However, a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less and Pb, Pb-Ca Alternatively, in a lead-acid battery having a negative electrode grid made of a Pb-Ca-Sn alloy, even in an open-type lead-acid battery in which an electrolytic solution is sufficiently present, the amount of oil addition is 0.2% by mass or more and 0.7% by mass or less. Relationship between the amount of Sn added in the positive electrode active material and the amount of Sb in the positive electrode lattice 1.5> T ≧ 0.15 × S + 0.05, applicable range, lignin amount in negative electrode active material, 0.3 mass % Or more and 0.8% by mass or less, the amount of the negative electrode active material / the amount of the positive electrode active material per cell is 0.6 or more, and the density of the positive electrode active material is 3.1 g / cm.³3.8 g / cm³By applying the following, it was confirmed that the same effect as the control valve type lead storage battery was obtained although the absolute value was different.
[0079]
【The invention's effect】
In a lead-acid battery using a positive / negative electrode plate containing no Sb in the positive / negative electrode grid, early capacity reduction occurs depending on charge / discharge conditions in cycle use. As a countermeasure, the above problem can be solved by using a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less in the positive electrode grid. When deposited on the negative electrode, the hydrogen overvoltage of the negative electrode is lowered, hydrogen gas is generated, and the balance of the sealed reaction function, which is a characteristic of the control valve type lead acid battery, is lost, and the function is lost, and the performance of the negative electrode plate is deteriorated. I was In contrast, a certain amount of oil is added to the negative electrode active material, a certain amount of Sn is added to the positive electrode active material, a certain amount of lignin is added to the negative electrode active material, and / or the amount of the negative electrode active material per cell By setting the ratio of the amount of the positive electrode active material to 0.6 or more, the above-mentioned adverse effects of Sb are suppressed, and the excellent cycle life performance inherent in the control valve type lead-acid battery or the open type lead-acid battery is obtained, and its industrial effects are obtained. Is extremely large.
[Brief description of the drawings]
FIG. 1 is a diagram showing the relationship between the cycle life and the Sb concentration in a positive electrode grid and the specific gravity of an electrolyte in a control valve type lead-acid battery.
FIG. 2 is a graph showing the relationship between the amount of oil added (% by mass) in the negative electrode active material of Example 1 and the cycle life.
FIG. 3 is a graph showing the relationship between the amount of Sn (% by mass) in the positive electrode active material of Example 2 and the cycle life.
FIG. 4 is a graph showing the relationship between the amount of lignin (% by mass) in the negative electrode active material of Example 3 and the cycle life.
FIG. 5 is a graph showing the relationship between the amount of negative electrode active material (g) / the amount of positive electrode active material (g) per cell and cycle life in Example 4.
FIG. 6 is a graph showing the influence of the amount of Sb (% by mass) in the positive electrode grid on the relationship between the positive electrode active material density and the storage battery capacity in Example 5.
FIG. 7 is a graph showing the influence of the amount of Sb (% by mass) in a positive electrode grid on the relationship between the positive electrode active material density and the cycle life of a storage battery in Example 5.

Claims

In a method for manufacturing a lead-acid battery having a positive electrode grid made of a Pb-Sb-based alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less,
A method for producing a lead storage battery, comprising adding 0.3% by mass or more and 0.7% by mass or less of oil to the negative electrode active material based on the mass of the negative electrode active material.

A lead-acid battery manufactured by the manufacturing method according to claim 1.

In a lead-acid battery having a positive electrode grid made of a Pb-Sb-based lead alloy having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less,
The mass of the positive electrode lattice (g) / the mass of the positive electrode active material (g) is 0.5 to 1.2, the amount of Sn contained in the positive electrode active material is T (% by mass), and the amount of Sb contained in the positive electrode lattice is When the amount is S (% by mass),
1.5> T ≧ 0.15 × S + 0.05.

In a lead-acid battery having a lead alloy positive electrode grid having an Sb concentration of 0.5% by mass or more and 1.5% by mass or less, the ratio of the amount of the negative electrode active material (g) to the amount of the positive electrode active material (g) is 0.6 per cell. A lead-acid battery characterized by the above.

The lead storage battery according to claim 2.

The lead storage battery according to claim 3.

The lead storage battery according to claim 2, 3 or 4.

The lead-acid battery according to any one of claims 2 to 8, wherein 0.3% by mass or more and 0.8% by mass or less of lignin are added to the amount of the negative electrode active material in the amount of the negative electrode active material.

The positive electrode active material density of 3.1 g / cm ³ or more, the lead acid battery according to any one of claims 2-9, characterized in that it is 3.8 g / cm ³ or less.