JPH01117270A - Manufacture of anode plate of lead-acid battery - Google Patents

Abstract

PURPOSE:To restrain the growth of a high resistance body at a boundary between a base board and active substance and to keep the performance of immediate use at a high level for a long period of time by forming with intermittent application of a current so that a cell voltage becomes a specified value after applying a current of a specific ratio with respect to a theoretical capacity of anode plate active substance. CONSTITUTION:Electrode plates finished with charging are water-rinsed, dried, and stored with separators interposed therebetween in a group of electrodes in a sealed case as a lead-acid battery of an immediate use type. During the storage, however, the anode plate develops grid oxidation due to active substances and a high resistance body produced at the boundary between a base board and the active substance reduces the immediate use performance of the battery. To prevent this, formation is performed with an intermittent weak current so that a cell voltage becomes 2.2-2.3V after applying a current 200% of a theoretical capacity of the anode active substance. As a result, a compact PbO2 layer is formed on the base board surface to restrict the growth of the high resistance body at the base board-active substance boundary of the anode plate during the storage so that the immediate use performance can be kept at a high level for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an improvement in the manufacturing method of a lead-acid battery anode plate.

Conventional technology Conventional ready-to-use lead-acid batteries have chemically formed anode plates and cathode plates.
After washing and drying, the battery is sealed and stored in a battery case using a separator as a group of electrode plates, and then filled with electrolyte when used. The performance required of a ready-to-use lead-acid battery is that it has enough voltage and capacity to start an automobile engine within a few minutes after being injected, and securing the voltage is especially important.

Hereinafter, the discharge voltage performance after injection will be considered as the immediate performance. The ready-to-use performance of a ready-to-use lead-acid battery gradually deteriorates during storage due to the formation of a high resistance material at the substrate-active material interface of the anode plate. The decline in ready-to-use performance is accelerated by temperature and moisture in the battery. Therefore, in order to suppress the decline in performance, methods have been adopted to store batteries at low temperatures and to reduce the amount of moisture inside the batteries.

Problems to be Solved by the Invention In a ready-to-use lead-acid battery, charged anode plates and cathode plates are washed with water, dried, and then stored as a group of plates in a battery case using a separator and sealed. However, during storage, the lattice of the anode plate is oxidized by the active material, resulting in stiffness and formation of a high resistance element at the substrate-active material interface.

This reaction rate is accelerated by temperature and moisture, but is greatly affected by the composition of the oxide film on the surface of the substrate, and if the oxide film contains many substances with low oxidation numbers, the ready-to-use performance will quickly deteriorate. It had drawbacks.

The process begins at the grating surface and then progresses inward from the plate surface. However, when a part of the substrate surface becomes pbo, the chemical conversion progresses from that location toward the surface, so lower oxides may be present in the oxide film even at the final stage of chemical formation. Therefore, as shown in the current pattern during chemical formation shown in FIG. 2, there is a method in which the process is intermittently paused at the end of chemical formation, and the unformed lower oxide is turned into lead sulfate to facilitate chemical formation. However, the current pattern in Figure 2 is an example when forming one 12Ah anode plate, and the forming current is 1.5A, which is 200% of the theoretical capacity of the anode plate active material (16 hours at 1.5A). After that, I took three breaks of one hour each. This results in
The oxide film on the substrate surface and the lower oxide of the active material are removed by pbo.
, can be converted into However, the potential of the anode plate during rest is equal to the equilibrium potential of pbo and pbso, and the Pb5O generated during rest does not change to pbo during rest. pbs for
o is stabilized and remains as it is even after subsequent chemical formation (charging). A battery using an electrode plate in such a state quickly loses its ready-to-use performance during storage.

Means for Solving the Problems In view of the above points, the present invention solves the problem by reducing the theoretical capacity of the anode plate active material to 2.
During chemical formation after 00% energization, the cell voltage intermittently dropped to 2.
Chemical formation is performed using a minute current of 2 to 2.3V.

A compact PBO layer is formed on the surface of the working substrate, which prevents the acceleration of the formation of high resistance at the substrate-active material interface of the anode plate during storage (and keeps the immediate performance at a high level for a long time). .

Example 36 B The anode plate (12Ah) for 20 series lead acid battery was
Chemical formation was performed using the current pattern shown in the figure. An anode plate was produced in which the cell voltage was changed depending on the minute current value in part a. The specific gravity of the electrolyte at this time is 1ρ60 at 20℃,
The temperature is 30°C. Batteries using these substrates were prepared and stored at 60° C. for July, and then their ready-to-use performance was examined. Immediate performance is the voltage at the 5th second when discharged for 150 days at 0℃,
The results are shown in FIG. Discharge direction (low cell voltage)
In the case of , the ready-to-use performance has deteriorated from the initial stage. In addition, in the charging direction, as the battery pressure increased, the ready-to-use performance after storage decreased.

Effects of the Invention As described above, according to the present invention, by improving the pbo, conversion rate of the oxide film on the substrate surface, the growth of a high resistance element at the anode plate substrate-active material interface is suppressed, and the ready-to-use performance is improved. It has great industrial value as it can be maintained at a high level for a long period of time.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the current pattern during chemical formation according to the present invention, and Figure 2 is a curve showing the relationship between the cell voltage at section b in Figure 1 and the ready-to-use performance after storage at 60°C for 7 days. In the figure, FIG. 3 is an explanatory diagram showing an example of a current pattern during conventional chemical formation. ￥1 Figure Time (1'L) Figure 3 Time (h)

Claims (1)

[Claims] In the chemical formation process of anode plates for lead-acid batteries, the process is characterized in that during formation after 200% of the theoretical capacity of the anode plate active material is energized, chemical formation is carried out intermittently with a minute current that produces a cell voltage of 2.2 to 2.3V. A method for producing a lead-acid battery anode plate.