JPH042064A - Bipolar type sealed lead acid battery - Google Patents

Abstract

PURPOSE:To suppress shortcircuiting resulting from slipping-off of active substance by forming a sheet of liquid retaining property from fine glass fibers, fine synthetic fibers, or a mixture thereof through paper making process, wherein the sheet is given an inter-electrode apparent specific gravity which is over a value as multiple of the apparent specific gravity at the time with no pressurization with a certain specific number. CONSTITUTION:When a battery is fabricated using a separator 4 consisting of a sheet of liquid retaining property obtained from fine glass fibers, fine synthetic fibers, or a mixture thereof through paper making process, the apparent specific gravity between electrodes shall be over 1.2 times as great as the apparent specific gravity at the time with no pressurization. Thereby the surface of electrode plate is pressurized in the perpendicular direction, and the separator 4 in the part not in contact with the electrode plates 2, 3 is arranged in such a way as enwrapping the electrode plates, so that slipping-off of the active substance is suppressed and eventually fallen active substance will stagnate in the recess of the separator 4 to prevent reaching the mating electrode plate. Thus shortcircuiting is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a bipolar sealed battery using bipolar plates.

Conventional technology and its challenges Bipolar technology uses a bipolar plate, in which a positive electrode active material is held on one side of the current collector and a negative electrode active material is held on the other side of the current collector, which has conductivity and does not allow liquid to penetrate. Bipolar batteries are used to manufacture batteries in which multiple cells are connected in series, and bipolar batteries that use bipolar plates are more efficient than conventional batteries that use the cell-to-cell connection method. Since the resistance between the cells is reduced, the voltage characteristics during charging and discharging are excellent.

However, in bipolar batteries, because one side of the active material is in contact with the current collector, it is difficult to supply electrolyte to that side, and the utilization rate of the active material is lower than in conventional batteries. In most cases, the structure consists of one negative electrode plate, and in order to improve capacity performance, the electrode plate must be made larger and the weight of the active material increased, or the electrode plate must be made thinner. It is necessary to increase the rate. When a battery is produced under these conditions, the battery is suitable for high-rate discharge performance, but it generally has the disadvantage that the gap between the electrodes becomes narrower and as the battery ages, it is more likely to cause short circuits due to shedding of the active material. Was.

Means for Solving the Problems The present invention is a bipolar battery using bipolar plates, in which a liquid-retaining sheet made of fine glass fibers, fine synthetic fibers, or a mixture thereof is used as a separator. When manufactured, by setting the apparent specific gravity of the gap between the electrodes of the sheet to be 1.2 times or more of the specific gravity when no pressure is applied, short circuits caused by falling off of the active material can be suppressed. It is something.

In a bipolar battery that uses working bipolar plates, when a battery is fabricated using fine glass fibers, fine synthetic fibers, or a liquid-retentive sheet obtained by mixing them as a separator, the gap between the electrodes of the sheet By making the apparent specific gravity of the part at least 1.2 times the apparent specific gravity when no pressure is applied, the electrode plate surface is pressurized from the vertical direction, and the portions that are not in contact with the electrode plate are The separator is arranged so as to wrap around the electrode plate, suppressing the active material from falling off, and preventing the fallen active material from accumulating in the recesses of the separator and reaching the other electrode plate, thereby preventing short circuits.

Embodiment FIG. 1 is a schematic diagram of a bipolar sealed battery before assembly according to the present invention, and FIG. 2 is a schematic diagram of a bipolar sealed battery after assembly according to the present invention. In FIG. 6, 1 is a current collector, and 2 is a current collector. A positive electrode plate, 3 a negative electrode plate, and 4 a separator.

Here, a bipolar sealed battery according to the present invention and a conventional bipolar sealed battery with a capacitance of 3Ah-6V with an electrode plate thickness of 2flllll and an electrode gap of 21111 were fabricated, and the discharge depth was 50% and the charge amount was 120%. When subjected to a charge/discharge life test, the conventional bipolar battery reached the end of its life after 150 cycles due to a short circuit caused by the cathode active material falling off. However, the bipolar sealed battery according to the present invention retained 80% of its capacity even after 600 cycles. This was caused by softening and falling off of the active material, but no short circuit was observed.

Effects of the Invention The present invention has the effect of improving the life performance of a bipolar sealed battery, and has great industrial value.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a bipolar sealed battery before assembly according to the present invention, and FIG. 2 is a schematic diagram of a bipolar sealed battery after assembly according to the present invention. 1... Current collector, 2... Diode plate, 3... Negative electrode plate, 4
...Separator Figure 1 Figure 1! Figure 12

Claims (1)

[Claims] 1. In a lead-acid battery consisting of a so-called bipolar structure plate in which the positive electrode active material and the negative electrode active material are each held on both sides of a single current collector, fine glass fibers, fine synthetic fibers, or a mixture of them are used. When a battery is manufactured using the resulting liquid-retaining sheet as a separator, the apparent specific gravity of the sheet between the electrodes is 1.2 of the apparent specific gravity when no pressure is applied.
A bipolar sealed lead-acid battery that is characterized by its ability to more than double its capacity.