JPS6043626B2 - Manufacturing method for cathode plates for lead-acid batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cathode plate for a lead-acid battery that improves high rate discharge performance at low temperatures and room temperatures.

Conventionally, lead-acid batteries installed in automobiles to start the engine often fail to start the engine due to low temperatures during the winter season or in cold regions. This is because the low-temperature, high-rate discharge performance of lead-acid batteries deteriorates, and the main cause is thought to be the cathode plate. In other words, the cathode plates of conventional lead-acid batteries are manufactured by adding ordinary additives such as barium sulfate, lignin, and carbon to lead powder to create a paste, and filling this paste onto the electrode grid. Among the additives, barium sulfate and carbon are said to improve life performance, and lignin is said to improve high rate discharge performance and life performance.Additive specifications include barium sulfate 0.3 to 2.0% and lignin 0.1%. It is thought that this is because the amount of lignin, which affects high rate discharge performance, is small, as the amount of lignin used is about 0.7% and carbon 0.1 to 0.5%.

However, if the amount of lignin added is simply increased compared to the conventional amount, the active material will expand and become prone to peeling off, which will actually shorten the life of the lead-acid battery. The present invention solves the above problem by filling an electrode plate grid with a paste containing 0.1 to 0.7% lignin and adding 0.8 to 0.7% lignin. This is a method for manufacturing a cathode plate for a lead-acid battery, which is characterized in that pastes containing 5.0% are filled in layers.

An embodiment of the present invention will be described.

Lead powder, barium sulfate 0.3-2.0%, lignin 0.
A cathode plate obtained by adding and kneading ordinary additives of 1 to 0.7% and carbon 0.1 to 0.5% to create a paste, and filling the electrode plate grid with a slightly smaller amount of this paste. On both sides, another paste made by blending 0.8 to 5% lignin and adding 0.3 to 2.0% barium sulfate as necessary is overlaid and filled to form a cathode plate for a lead-acid battery. Manufacture.

Therefore, the cathode plate obtained above has lignin of 0.8
A paste containing ~5.0% is filled on the surface of the cathode plate, and the inside is made of normal paste, so that lignin uniformly expands only on the surface of the active material of the cathode plate in a lead-acid battery. This increases the contact area for electrochemical reactions and improves high-rate discharge performance, but since the inside of the active material expands only to the same extent as before, the active material does not peel off from the electrode grid. It does not shorten the life of lead-acid batteries.

Moreover, since the above cathode plate contains lignin in the paste,
The initial performance of the battery is maintained for a long period of time, with little variation. However, if the lignin content in the paste filling the surface is less than 0.8%, the lignin content will be approximately the same as the paste filled inside, so the lignin content will be as high as that of conventional cathode plates. Only discharge performance can be obtained, and if the surface lignin content exceeds 0%, even the active material inside the cathode plate will expand excessively, making it easy for the active material to fall off.

N5OZ lead-acid battery using the cathode plate obtained by the present invention (invention product A) and a conventional lead-acid battery of the same shape (conventional product B)
The relationship between high rate discharge performance and charge/discharge cycle at room temperature (25°C) and low temperature (-15°C) is shown in FIGS. 1 and 2, respectively.

This is an SAE in which one charge/discharge cycle is charging at 14.8V for 10 minutes and discharging at 25A for 2 minutes.
During the life test based on the standard, initial stage, 2000th cycle, 4
At the 000th cycle and the 6000th cycle, 30
These are the results of measuring the duration of 0A high rate discharge. From the above results, it was found that the product A of the present invention has a higher high rate discharge performance than the conventional product B, and also shows little change over time and maintains a high level.

As described above, the present invention makes it possible to improve the high rate discharge performance at low and normal temperatures without shortening the life of the lead-acid battery, maintain its initial performance for a long period of time, and manufacture a cathode plate with less variation. It is extremely valuable.

[Brief explanation of drawings]

Figure 1 is a curve diagram showing the relationship between high rate discharge performance and charge/discharge cycle at room temperature (25°C) of a lead-acid battery using the cathode plate obtained by the present invention and a conventional lead-acid battery, and Figure 2 is the same. It is a curve diagram showing the relationship between high rate discharge performance and charge/discharge cycle at low temperature (-15°C). A is a product of the present invention, B is a conventional product.

Claims (1)

[Claims] 1 Fill the electrode plate grid with a paste containing ordinary additives containing 0.1-0.7% lignin, and then overlay paste containing 0.8-5.0% lignin on both surfaces. A method for manufacturing a cathode plate for a lead-acid battery, characterized by filling the cathode plate with