JPS5889781A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To improve high rate charge-discharge performance and a charge-discharge cycle life of a sealed lead-acid battery by using a lead alloy grid containing no Sb such as a Pb-Ca alloy and adding either or the mixture of boric acid and/or borate to an electrolyte. CONSTITUTION:By making an electrode plate thin by using an alloy grid containing no Sb such as Pb-Ca, Pb-Ca-Sn in a sealed lead-acid battery. The utilization of a positive active mass is increased and high rate charge-discharge performance is improved. Addition of 0.005-0.03g/cc of either or the mixture of boric acid and/or borate to an electrolyte prevents softening and exfoliation of a cathode active mass during charge-discharge cycle and improves a charge-discharge cycle life.

Description

【発明の詳細な説明】 本発明は、密閉形鉛蓄電池の高率充放電特性の改善なら
びに充放電す、イクル寿命の改善を目的としたものであ
る。DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to improve the high rate charging and discharging characteristics of a sealed lead acid battery and to improve the cycle life during charging and discharging.

従来、密閉形鉛蓄電池には自己放電が少なく、保存寿命
を長くするために格子合金としてｐｂ　−Ｃａ合金ある
いはＰｂ　−Ｃａ　−！’、ｎ合金等アンチモンを含ま
ない合金が用いられてきた。しかしながらこの種の合金
は充放電サイクル中の陽極板活物質の軟化脱落を促進さ
せ、特にＣａを含有する合金はその傾向を顕著にすると
言われているためサイクル用途には適していなかった。Conventionally, sealed lead-acid batteries have low self-discharge and have a long storage life using lattice alloys such as pb-Ca alloy or Pb-Ca-! ', n-alloys and other alloys that do not contain antimony have been used. However, this type of alloy is said to promote the softening and falling off of the anode plate active material during charge/discharge cycles, and alloys containing Ca in particular are said to make this tendency more pronounced, so they are not suitable for cycle applications.

このためサイクル用途に用いる場合には、陽極板の活物
質充填密度を大きくシ、陽極板を３ｍｍ程度と厚くシ、
電解液比重を１．３０以Ｆと低くするなどの対策が打た
れてきたが、いずれも陽極活物質の反応効率を減じ、小
形軽量化、高率放電特性改善の大きな支障となっていた
。Therefore, when used for cycle applications, the active material packing density of the anode plate should be increased, and the anode plate should be made as thick as about 3 mm.
Countermeasures have been taken, such as lowering the specific gravity of the electrolyte to 1.30 F or higher, but all of these methods reduce the reaction efficiency of the anode active material, posing a major hindrance to reducing size and weight and improving high-rate discharge characteristics.

本発明は電解液中にホウ酸またはホウ酸塩を添加するこ
とで問題解決を図ったものである。以下、実施例として
、格子をＰｂ　−Ｃａ　−Ｓｎ合金等のアンチモンを含
まない合金で形成する例について説明する。この格子体
に酸化鉛、希硫酸より成るペースを充填し厚さ２ｍ１ｎ
の陽極板とすると共に、酸化鉛、希硫酸、硫酸バリウム
等より成るペーストを充填し厚さ２ｍｍの陰極板とした
ものを、繊維径１０μ以下のガラス繊維から成るマット
状セパレータを用い、陽極板３枚、陰極板４枚の構成で
組み合わせ、希硫酸１００当たりｏ、０３ｇの四ホウ酸
す）　ＩＪウムを添加した電解液を注入し、充電後の電
解液比重を１．３２にした１、６時間率容量２．６ムｈ
の電池の実験結果を示す。第１図は電流別の陽極活物質
利用率を・示し、第２図は充電を９０分。The present invention attempts to solve the problem by adding boric acid or a borate salt to the electrolyte. Hereinafter, as an example, an example will be described in which the lattice is formed of an alloy that does not contain antimony, such as a Pb-Ca-Sn alloy. This grid was filled with a paste consisting of lead oxide and dilute sulfuric acid to a thickness of 2m1n.
The anode plate was made into a 2 mm thick cathode plate filled with a paste made of lead oxide, dilute sulfuric acid, barium sulfate, etc., and a mat separator made of glass fiber with a fiber diameter of 10 μm or less was used to make the anode plate. A combination of 3 plates and 4 cathode plates was injected with an electrolytic solution containing 0.03 g of tetraboric acid per 100 dilute sulfuric acid, and the specific gravity of the electrolyte after charging was 1.32. 6 hour rate capacity 2.6 mh
The experimental results of the battery are shown below. Figure 1 shows the anode active material utilization rate by current, and Figure 2 shows charging for 90 minutes.

放電は１６ムで１，６Ｖ／セ・までとした充放電サイク
ル寿命の１例である。This is an example of a charge/discharge cycle life in which the discharge was up to 1.6 V/sec for 16 μm.

ストを充填し厚さ３ｍｍの陽極板とし、本発明の実施例
と同じ厚さ２ｍｍの陰極板を、繊維径１０μ以下のガラ
ス繊維から成るマット状セパレータを用い、陽極板２枚
、陰極板３枚の構成で組み合わせ希４ａ酸を注入し充電
後の電解液比重を１．３２にし量率容量２，７Ａｈの電
池である。なお、いずれの電池も同容積の電槽にて組立
てた。A cathode plate with a thickness of 2 mm, which is the same as in the embodiment of the present invention, was filled with a matte separator made of glass fibers with a fiber diameter of 10 μm or less, and two anode plates and three cathode plates were prepared. It is a battery with a combination of two batteries, injected with dilute 4a acid, and with an electrolyte specific gravity of 1.32 after charging, and a mass rate capacity of 2.7Ah. Note that both batteries were assembled in containers with the same volume.

第１図で、本発明品は高率放電において従来例１より・
も優れている７５＝、ｆ米例２−よりは６％程劣る。In Figure 1, the product of the present invention is lower than the conventional example 1 in high rate discharge.
75=, which is also excellent, is about 6% inferior to Example 2-.

しかしながら第２図で示したように、充放電サイクル寿
命で大きな差があり、本発明品は従来例１゜２よりも優
れていることが判る。However, as shown in FIG. 2, there is a large difference in charge/discharge cycle life, and it can be seen that the product of the present invention is superior to the conventional example 1°2.

このように本発明は従来Ｐｂ　−（ａ　、　Ｐｂ　−Ｃ
ａ　−８ｎ　等の合金格子を用いた極板を薄くすること
により、陽極板活物質利用率を上げ、高率放電特性を改
善することができるものであり、充放電サイクル中に陽
極活物質の軟化脱落を促進するため困難とされていたも
のを、充放電サイクル寿命を短縮することなく可能にし
たものである。As described above, the present invention can be applied to conventional Pb-(a, Pb-C
By thinning the electrode plate using an alloy lattice such as a-8n, it is possible to increase the utilization rate of the anode plate active material and improve the high rate discharge characteristics. This was previously considered difficult because it promotes softening and shedding, but it has now been made possible without shortening the charge/discharge cycle life.

なお、セパレータとして用いるガラス繊維から成るマッ
ト状セパレータの繊維径は１０μ以上では電解液の保持
力が劣り、容量１人り当り１０ｃｃ以下の電解液耽とす
ることはできない。また陽極活物質の脱落しだ浮遊粒子
を透過して早期寿命劣化をもたらすので１０μ以下がよ
い。また電解液に添加するホウ酸塩としての四ボウ酸ナ
トリウムは電解液Ｉ　ＯＣあたり０．００６１７以下で
は効果がなく、逆に０．０３１７以上では放電容量減少
が添加しない場合と比較して６％以上と大きくなるので
ｏ、ｏｏｓ〜ｏ、０３シＯＣとするとよい。勿論ホウ酸
を用いることも、ホウ酸とホウ酸塩とを混合して用いる
こともできる。用いるアンチモンを含まない鉛合金のう
ち、Ｐｂ−Ｃａ合金においては（ａ含有量がｏ、ｏｃｓ
ｗｔ％以下では強度が不十分であり、逆に０，１２ｗｔ
％　以上では耐食性が劣る。またＰｂ　−Ｃａ　−Ｓｎ
合金においてＣａ含有量がｏ、ｏｓｗｔ％以下では強度
が不十分であり、Ｑ、１２ｗｔ５１６以上では耐食性が
劣る。Ｓｎ含有量は０，３ｗｔ％以下では耐食性を上げ
る効果が少＜ｂ　１．。Note that if the fiber diameter of the mat-like separator made of glass fiber used as a separator is 10 μm or more, the holding power of the electrolyte will be poor, and the capacity of the electrolyte solution per person cannot be 10 cc or less. In addition, the thickness is preferably 10 μm or less since floating particles that fall off the anode active material can pass through and cause premature deterioration of life. In addition, sodium tetraborate as a borate added to the electrolyte has no effect if it is less than 0.00617 per electrolyte IOC, and on the other hand, if it is more than 0.0317, the discharge capacity decreases by 6% compared to when it is not added. Since it becomes large as above, it is preferable to use o, oos to o, 03shi OC. Of course, boric acid can be used, or a mixture of boric acid and borate can also be used. Among the lead alloys that do not contain antimony, in the Pb-Ca alloy (a content is o, ocs
If it is less than 0.12 wt%, the strength is insufficient;
% or more, corrosion resistance is poor. Also, Pb -Ca -Sn
If the Ca content in the alloy is less than 0.0swt%, the strength will be insufficient, and if the Ca content is more than 516%, the corrosion resistance will be poor. If the Sn content is 0.3 wt% or less, the effect of increasing corrosion resistance is small. 1. .

ｗｔ％以上では強度が不足するうえにコスト増になるの
で避けるべきである。If it exceeds wt%, the strength will be insufficient and the cost will increase, so it should be avoided.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は放電々流に対する陽極活物質利用率を示す図、
第２図は充放電サイクル寿命を示す図である。Figure 1 is a diagram showing the utilization rate of anode active material with respect to discharge flow;
FIG. 2 is a diagram showing the charge/discharge cycle life.

Claims (3)

【特許請求の範囲】[Claims] （１）陽極活物質が軟化脱落し易いＰｂ　−Ｃａ合金等
アンチモンを含まない鉛合金製格子体を用い、ホウ酸ま
たはホウ酸塩を単独あるいは混合物として電解液中に添
、加したことを特徴とする密閉形鉛蓄電池。(1) A grid made of a lead alloy that does not contain antimony, such as a Pb-Ca alloy, in which the anode active material easily softens and falls off, is used, and boric acid or a borate salt is added to the electrolytic solution, either alone or as a mixture. A sealed lead-acid battery. （２）ホウ酸またはホウ酸塩あるいはそれらの混合物が
０．ｏｏ６〜０．０３ｇ／Ｃｃの割合で電解液中に添加
されている特許請求の範囲第１項記載の密閉形鉛蓄電池
。(2) Boric acid or a borate salt or a mixture thereof is 0. The sealed lead-acid battery according to claim 1, wherein the electrolyte is added at a rate of 6 to 0.03 g/Cc. （３）電解液量が容量１ムｈ当り１０００以下に制限さ
れた特許請求の範囲第１項または第２項記載の密閉形鉛
蓄電池。(3) The sealed lead-acid battery according to claim 1 or 2, wherein the amount of electrolyte is limited to 1,000 or less per 1 μh of capacity.