JPH03173066A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To reduce the exposed area of copper or a copper alloy to improve battery performance by expanding a copper or copper alloy thin plate, forming a covered layer made of lead or a lead alloy on the surface of the expanded plate, filling active material plate therein to form a belt-like negative plate, cutting the negative plate, folding up it, then combining it with a positive plate to form a plate group. CONSTITUTION:A copper or copper alloy thin plate is expanded, and lugs or feet are formed in a non-expanded part. A covered layer made of lead or a lead alloy is formed on the surface of the expanded plate, and active material plate is filled therein to form a belt-like negative plate 13. The negative plate 13 is cut in plural pieces and the cut negative plate 13 is folded up and combined with a positive plate 15 to form a plate group. Since the exposed area 16 is reduced to only two, elution of copper in charge-discharge of a battery is decreased and electric conductivity is increased compared with a conventional plate in which an expanded grid made of lead alloy is used. Electric conductivity is increased, high-rate discharge performance is enhanced, and deterioration in performance caused by elution of copper is avoided or reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lead-acid battery, and more particularly to an improvement in a battery using a lead-acid battery electrode plate obtained by expanding a thin plate made of copper or a copper alloy.

Conventional technology and its issues @Storage batteries are widely used as power sources for power, transportation, and stationary use, and are widely used for starting automobiles because of their low cost and excellent high-rate discharge. Currently, there are several demands on lead-acid batteries for starting automobiles, such as longer life and improved high-temperature resistance due to their usage conditions, and one of these is a demand for higher output.

Generally speaking, methods for increasing the output of lead-acid batteries for starting automobiles, which have a 6-cell monoblock structure, include improving the inter-cell connection method to reduce the resistance at the inter-cell connections, and reducing the spacing between the electrode plates. Possible methods include reducing the resistance between the electrodes and increasing the concentration of dilute sulfuric acid as the electrolytic solution. However, these improvements have already reached their limits. Another method is to use a lattice with excellent voltage characteristics, optimizing the shape such as a lattice with diagonal lattices or a lattice with radial lattices, and using materials with good electrical conductivity. It is conceivable to use Copper and copper alloys are the most suitable materials with good electrical conductivity, considering the cost.

When copper or a copper alloy is used as a grid, if its surface is exposed, that is, the surface of the copper or copper alloy is exposed directly to the electrolyte. When in contact with acid, when used as a positive electrode, copper is eluted and deposited on the negative electrode plate, and when used as a negative electrode, reactions other than the charging and discharging reactions of lead-acid batteries occur in the exposed portion.

That is, during charging, a hydrogen gas generation reaction occurs and the charge of the negative electrode active material becomes insufficient, and while the negative electrode active material is left unused, the negative electrode active material
The local battery is constructed with metallic lead, which increases self-discharge. Therefore, it is necessary to form a lead or lead alloy coating on the surface of a grid made of copper or prepared alloy by electroplating or immersing it in molten metal.

Grids made of copper and prepared alloys are already used in large-scale batteries, such as lead-acid batteries for submarines, but the manufacturing process is extremely complicated, and as is, they are used in large quantities to produce low-cost automobiles. Therefore, as a manufacturing method that can be applied to lead-acid batteries for starting cars, a thin plate made of copper or prepared alloy is expanded, and ears and feet are added to the unexpanded parts. After molding, a coating layer of lead or lead alloy is formed on the surface, which is then filled with paste and cut into predetermined dimensions to obtain the electrode plates.We have been studying a continuous method for producing electrode plates for lead-acid batteries. .

However, this manufacturing method has a problem in that new exposed surfaces of copper or copper alloy appear when the paste is filled and cut into predetermined dimensions.

Means for Solving the Problems In the present invention, a thin plate made of copper or a prepared alloy is expanded, necessary parts such as ears and feet are formed in the unexpanded parts, and the surface is coated with lead or By forming a coating layer made of lead alloy and filling this with paste, a strip-shaped negative electrode plate is cut into a series of plates, bent, and combined with a positive electrode plate to form an electrode plate group. The present invention aims to provide a lead-acid battery that eliminates or reduces the drawbacks of conventional methods.

Example An embodiment of the battery of the present invention will be described below with reference to the drawings.

Figure 1 is a schematic diagram of the manufacturing process showing an example of a method for manufacturing electrode plates for lead-acid batteries using a copper grid. The expander 3 is a punching machine for forming ears and feet. The thin copper plate 1 that has passed through this punch n3 is processed into an expanded grid 4. The expanded grid 4 is immersed in a cleaning liquid 5 in a cleaning tank 6 and washed in a washing tank 7. Next, a thin third layer of lead or lead alloy is formed in a plating tank 8, and an active material paste 10 is prepared by kneading lead powder, which will become the active material of a lead-acid battery, and a small amount of additives with dilute VA acid in a filling machine 9. is filled. The expanded grid 4 filled with the active material paste 10 in this manner is cut by the next cutting machine 11 to become the electrode plate 12.

Figures 2A, B, and C are diagrams showing examples of the shape of the negative electrode plate used in the battery of the present invention.9 The negative plate used in the battery of the present invention is not cut into a single plate but is a series of plates consisting of a plurality of plates. do. The negative electrode plates in FIG. 2 each consist of electrode plates equivalent to five single electrode plates. In Figure 2, A shows the case where the number of electrode plates is the same as the number of single electrode plates, and B and C show the cases where the number of electrode plate ears is less than the number of single electrode plates. The negative electrode plate 14 is an electrode plate lug.

FIG. 3 is a schematic diagram of an electrode plate group for a battery according to the present invention in which the negative electrode plate 13 is combined with the positive electrode plate 15.

In conventional lead-acid batteries, exposed surfaces of copper or copper alloy that are created when width-cutting copper expanded grid electrode plates exist at both ends of each single electrode plate, but in the lead-acid battery according to the present invention, exposed surfaces 16 are present at two locations. Since the amount of copper is smaller than before, there is less copper elution when the battery is charged and discharged, and it has better electrical conductivity than the conventional electrode plate using an expanded lattice made of shipboard metal, so it is used as a lead-acid battery for starting automobiles. The high-rate discharge performance, which corresponds to the particularly demanding discharge during vehicle start-up, has been improved, and the problems that occur when copper or copper alloys are used for the grid body have been solved.

Furthermore, since the expanded grid made of copper or prepared alloy has good electrical conductivity, there was almost no deterioration in battery performance even if the number of electrode plates was reduced compared to the conventional one. Furthermore, it is also possible to use one plate per plate group, as shown in FIG.

Effects of the Invention As detailed above, the lead-acid battery according to the present invention uses an expanded grid made of regular or prepared alloy as the grid, so it has higher electrical conductivity than the conventional electrode plate using an expanded grid made of ship metal. This improves high-rate discharge performance, and since there are fewer exposed surfaces of copper or copper alloy than before, problems such as deterioration of lead-acid batteries due to copper elution can occur when copper or copper alloy is used in the grid. All problems can be solved or alleviated, and its industrial value is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a manufacturing process showing an example of a method for producing an electrode plate for a lead-acid battery using a copper grid, Fig. 2 is a diagram showing an example of the shape of a negative electrode plate used in a battery of the present invention, and Fig. 3 is a diagram showing an example of the shape of a negative electrode plate used in a battery of the present invention. FIG. 2 is a schematic diagram of an electrode plate group for an invention battery.

Claims (1)

[Claims] 1. Expanding a thin plate made of copper or copper alloy,
Necessary parts such as ears and feet are formed on the unexpanded part, a coating layer made of lead or lead alloy is formed on the surface, and this is filled with paste to form a band-shaped negative electrode plate. A lead-acid battery characterized by cutting and bending a series of multiple electrode plates and combining them with a positive electrode plate to form a group of electrode plates.