JPS61198574A - Lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a lead storage battery which has superior recovering ability after being left discharged by being provided with a negative plate having greater capacity than a positive electrode and making the ratio of theoretical discharge capacity of a positive plate against that of electrolyte to be less than one. CONSTITUTION:The battery is provided with a positive electrode and a negative plate which has greater capacity than the positive electrode, and the ratio of theoretical discharge capacity of the positive plate against that of electrolyte is made less than one. Thus, even if a battery being left discharged, the positive plate comes under every low atmosphere of electrolyte. Hence, since inactive PbSO4 increases dissolving ability and charging current is prevented from decreasing due to passivation during the constant-voltage charging, charging performance can be enhanced.

Description

[Detailed description of the invention] Industrial applications The present invention relates to improving the performance of lead-acid batteries.

Conventional technology Conventionally, the lead alloys mainly used in grids for lead-acid batteries are lead-antimony (also containing arsenic, tin, etc.), lead-antimony, etc.
There are lead alloys such as calcium-based (also containing tin, aluminum, etc.).

When a lead-antimony based lead alloy is used and the antimony content is 396 or more, the mechanical strength is excellent,
It is widely used because of its good workability and durability against stress corrosion, but the antimony contained in the lattice and the SbS+ ions eluted from the anode lattice through oxidation are Sb at the cathode.
Antimony, which is produced by electrodeposition as a battery, lowers the hydrogen overvoltage at the cathode, making it more likely to cause electrolysis of water during charging (and, moreover, cause a local cell reaction on the surface of the cathode plate when left unused, resulting in self-destruction). There were drawbacks such as increased discharge.

In order to improve these problems, lead-calcium alloys, which have relatively good mechanical strength, are used in some parts. However, when batteries using this type of alloy are repeatedly charged and discharged deeply, a passive film is formed at the interface between the anode active material and the lattice at the anode, causing a problem in which the battery capacity quickly decreases. After complete discharge, charging current becomes difficult to flow during constant voltage charging, and the battery characteristics are deteriorated without sufficient capacity recovery.

In particular, when a lead alloy that does not substantially contain antimony (e.g., lead-calcium, lead-tin, lead-strontium alloy, etc.) is used in the anode grid alloy, or when water is used to suppress electrolyte loss during use, In order to increase the electrolytic voltage of the cathode plate, when the grid alloy of the cathode plate is combined with a lead alloy as mentioned above which does not contain substantially antimony, the anode grid alloy is combined with a lead-antimony based lead alloy with an antimony content of 3% or less. The lead-acid battery having the structure used had a drawback in that if it was left to discharge, it became difficult for the charging current to flow during constant voltage charging.

Problems to be Solved by the Invention The present invention addresses the above points and improves the constant voltage chargeability of a lead-acid battery having a structure in which the anode lattice contains antimony of 396 or less and the cathode lattice contains substantially no antimony. The purpose is to provide a method for improving.

Means for Solving the Problems The present invention is characterized in that it comprises an anode and a cathode plate having a larger capacity than the anode, and the ratio of the theoretical discharge capacity of the anode plate to the theoretical discharge capacity of the electrolyte is less than 1. That is.

Effect: Due to the above features, even when left undischarged,
The anode plate has a very low electrolyte atmosphere, thereby increasing the solubility of the inert 4bso4, suppressing a decrease in charging current due to passivation during constant voltage charging, and improving charging performance.

Example An embodiment of the present invention will be described.

By casting, the sb content is 1.5%, 2.996.
4.3% (others are As O, 3%5, Sn 0.5%5
, Se O, 05%) and Pb-0,0696Ca-0,396Sn obtained by casting.
A cathode grid consisting of -0,0296 AI was used. Each grid body was filled with a specified active material paste, dried, and inserted into a battery case together with a separator according to a conventional method. Dilute sulfuric acid was then injected for initial charging, and the electrolyte specific gravity was adjusted to 1.280. .

In the above battery production, as shown in the first blue (1), trial production was carried out by filling the paste so that the anode lattice with different sb content had an amount of active material with various changes in the anode theoretical capacity.

Note that the theoretical capacity of the cathode was larger than the capacity of the anode for each battery. The prototype battery was made to have a capacity 1.3 times the theoretical capacity of the anode.

Table 1 [ ] It was removed and left open in a 40°C water tank for two weeks. After that, a constant voltage of 2.5 V/cell (limited current 30 A) was applied at 40°C.
) The current was measured 30 minutes after charging.

Table 2 summarizes the charging currents at that time.

Table 2 For batteries with a theoretical discharge capacity of 1 or more (A series, B series), when the antimony content in the anode lattice alloy decreases, the charging current becomes difficult to flow, and the passivation of the anode plate causes the antimony content to decrease. This shows that it is likely to occur. For it,
Batteries (D series, A series) in which the theoretical discharge capacity of the anode was less than 1 compared to the theoretical discharge capacity of the electrolyte had good chargeability regardless of the antimony content in the anode lattice alloy. In batteries (C series) with a discharge capacity ratio close to 1, the charging current tends to decrease slightly as the Sb content decreases, but 30 A was recorded after 10 minutes.

From this result, when the antimony content of the anode lattice is 3% or less, in order to prevent the formation of a passive film, the ratio of the theoretical discharge capacity of the anode plate to the theoretical discharge capacity of the electrolyte should be less than 1. It was found that this is effective in improving chargeability after discharging.

The gist of the present invention is that in a battery configuration consisting of an anode plate in which the antimony content in the anode lattice alloy is 3% or less, if the theoretical discharge capacity of the anode plate is less than or equal to the theoretical discharge capacity of the cathode plate, the theoretical discharge capacity of the anode plate is The electrolyte can be charged by maintaining a capacity ratio that dissolves the electrochemically inert lead sulfate produced on the anode plate by discharging by setting it to 1 vortex compared to the theoretical discharge capacity of the electrolyte, or by leaving it for a while. It is thought that this is because the increase in charging overvoltage can be suppressed during charging, and charging can easily occur even with constant voltage charging that regulates charging overvoltage.

If the lattice alloy contains a large amount of antimony, antimony is likely to be eluted by the self-discharge reaction of the anode plate during standing after discharge, resulting in the formation of a passive film on the lattice surface, which is the current collector. It is thought that this is unlikely to occur, or even if it does occur, it is maintained in an electrically active state, but the details are unknown.

Although this embodiment uses a cast lattice as the lattice, similar effects can be expected even when an expanded lattice obtained by machining or the like is used.

Effects of the Invention As described above, according to the present invention, a lead-acid battery with good recovery properties after being left to discharge can be obtained.

Its industrial value is enormous.

Claims (3)

[Claims] (1) A lead-acid battery comprising an anode and a cathode plate having a larger capacity than the anode, the ratio of the theoretical discharge capacity of the anode plate to the theoretical discharge capacity of the electrolyte being less than 1. (2) The lead-acid battery according to claim 1, wherein the anode plate is made of a lead-antimony-based lead alloy, and the cathode plate is made of a lead alloy that does not substantially contain antimony. (3) The lead-acid battery according to claim 1, wherein the anode grid is a lead-antimony based lead alloy containing 3 weight percent or less of antimony.