JPH042047A - Bipolar type sealed lead acid battery - Google Patents

Abstract

PURPOSE:To prevent shortcircuiting resulting from slipping-off of active substance and prolong the lifetime by making a separator with a recess approx. in the same shape as an electrode plate provided in a solution retaining sheet, and fitting the electrode plate in this recess in the separator. CONSTITUTION:A bipolar battery according to the present invention includes a separator sheet 4 having liquid retaining property, which is made of fine glass fibers or fine synthetic fibers or mixture thereof produced through paper making process, and in this sheet a recess is formed in approx. the same shape as electrode plate. Electrode plates 1 and 3 are fitted in this recess from both sides. The surface of electrode plate is pressurized, and active substance having softened and slipped off stagnates in the recess, not reaching the mating electrode plate, and thereby shortcircuiting is prevented. Use of this type of sheet can also increase the electrolyte holding amount to lead to prolongation of the lifetime.

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 provides a bipolar battery using bipolar plates, in which the plate is partially formed of fine glass II fibers, fine synthetic fibers, or a liquid-retaining sheet obtained by mixing them. A separator with a recess of almost the same shape as the separator is used, and by arranging the recess and the electrode plate to fit together, it is possible to suppress short circuits caused by active material falling off. be.

Function: In a bipolar battery that uses bipolar electrode plates, a concave portion with almost the same shape as the electrode plate is provided in a part of a liquid-retentive sheet made of fine glass fibers, fine synthetic fibers, or a mixture thereof. Since the electrode plate is arranged so that it fits into the recess of the sheet, the electrode plate surface is pressurized from the vertical direction, and the fallen active material accumulates in the recess of the sheet and is attached to the other electrode plate. This prevents short circuits from occurring. Furthermore, the use of such a sheet has the effect of increasing the capacity for holding the electrolyte.

Example Figure 1 is a perspective view of a separator used in the battery of the present invention, Figure 2 is a perspective view of a separator used in the battery of the present invention.
The figure is a side view of the device, in which a concave portion with almost the same shape as the electrode plate is provided in a part of a liquid-retentive sheet made of fine glass fiber, WJ, Is synthetic fiber, or a mixture of these. be.

Furthermore, FIG. 3 is a schematic diagram showing the basic configuration of the bipolar sealed lead acid battery of the present invention. In the figure, 1 is a positive electrode plate, 2 is a current collector, 3 is a negative electrode plate, and 4 is a separator.

Here, it consists of the basic configuration shown in Fig. 3, and the electrode plate thickness is 2n.
A bipolar sealed battery according to the present invention and a conventional bipolar sealed battery with a capacitance of 3Ah-6V with an electrode spacing of 2 inches were manufactured and subjected to a charge/discharge life test with a discharge depth of 50% and a charge amount of 120%. As a result, 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, even after 600 cycles, the bipolar sealed battery according to the present invention has a
It held % capacity. 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]

Figure 1 is a perspective view of the separator used in the battery of the present invention;
The figure is a side view thereof, and FIG. 3 is a schematic diagram showing the basic configuration of the bipolar sealed lead acid battery of the present invention. 1... Positive electrode plate, 2... Current collector, 3... Negative electrode plate, 4
... Separator perspective view Figure 1 Side view Figure 2 Figure 3

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. A bipolar type characterized in that a part of the resultant liquid-retaining sheet has a recess in the shape of the electrode plate and is used as a separator, and the recess is arranged so that the electrode plate fits into the recess. Sealed lead acid battery.