JPS62122058A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To eliminate concentration difference in electrolyte produced in a battery by arranging one end of a fine tube inside a porous separator, and reducing the pressure in the other end to pump the electrolyte up in the porous separator, and transferring the electrolyte from the upper part to the lower part, and vice versa. CONSTITUTION:One end of a fine tube 4 is arranged in a porous separator 3 and the other end is connected to a pump 5. An electrolyte is transferred to the bottom of battery through an electrolyte flow tube 6 from the pump. The pump 5 reduces the pressure in the fine tube 4 to pump the electrolyte up from the porous separator and discharges it from the other outlet. Thereby, low concentration sylfuric acid in the upper part is transferred to the bottom and mixed to the high concentration sulfuric acid to make it uniform. By circulation of the electrolyte, the concentration of electrolyte is made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to improvements in sealed lead-acid batteries used particularly in applications where charging and discharging are repeated.

Conventional technology and its problems Sealed lead-acid batteries, in which the electrolyte is absorbed and retained in the positive electrode plate, negative electrode plate, and porous separator, have no flowing liquid (the electrolyte is difficult to move). Compared to conventional lead-acid batteries, the rate at which high-density sulfuric acid generated on the electrode plates during charging settles and causes a concentration difference in the electrolyte inside the battery is slower, but because the electrolyte inside the porous body is continuous, When charging and discharging are repeated, a difference of 81 degrees gradually arises.In conventional lead-acid batteries, this concentration difference is completely caused by the Wt itching effect when gas generated by overcharging rises in the electrolyte due to buoyancy. On the other hand, in a sealed lead-acid battery, even if overcharged, the above-mentioned stirring effect cannot be expected, and it is difficult to eliminate the 'fA degree difference within the battery once generated. If a battery is left for a long period of time with such a concentration difference, sulfur Fi will be present in the active material exposed to high concentration sulfuric acid at the bottom.
! Lead accumulates in a concentrated manner and is not activated even when charged, causing a decrease in battery capacity.

Means for Solving the Problems The present invention solves the above-mentioned drawbacks and provides a sealed lead-acid battery capable of eliminating the difference in concentration of the electrolyte. In other words, by placing the tip of a thin tube inside the porous separator and vacuuming the other end to suck up the electrolyte inside the porous separator, the electrolyte from the upper part of the battery can be moved to the bottom or vice versa. This eliminates the electrolyte concentration difference that occurs within the battery by avoiding electrolyte migration.

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

FIG. 1 is a longitudinal cross-sectional view of essential parts showing the principle of the sealed lead-acid battery of the present invention, in which 1 is a positive electrode plate, 2 is a negative electrode plate, and 3 is a porous separator that sufficiently absorbs and retains an electrolyte. 4 is a thin tube, one tip of which is placed in a porous separator, and the other tip is connected to a pump 5. 6 is a tube for electrolyte outflow from the pump, and the structure is such that the electrolyte is sent to the bottom of the battery. 7 is a battery container. The pump 5 sucks up the electrolyte by reducing the pressure of the thin tube whose tip is placed in the porous separator.
Any structure may be used as long as the electrolyte can be sent out from another outlet. In general, in sealed lead-acid batteries, the porous separator has many pores that absorb and retain the electrolyte through the capillary condensation force. It is possible to suck it up. The electrolyte is pumped to the bottom of the cell, where it is absorbed again by the porous separator at the bottom and rises. In this way, even if there is a 1IHJt difference in electrolyte in the battery, the upper
Once 1i1!11! Since I is transported to the bottom and mixed with highly concentrated sulfuric acid to be homogenized, and the electrolyte is circulated, it is possible to maintain a uniform 'fA degree throughout the battery.

Figure 1 shows a structure that transports the electrolyte from the top of the porous separator to the bottom of the battery, but it is also possible to arrange the tip of the II tube at the bottom of the separator and drain the electrolyte to the top of the separator. can be,
If the fluid remains at the bottom of the battery, it is of course possible to transport this fluid to the top.

As described above, the sealed lead-acid battery according to the present invention is very effective because it can eliminate the difference in am of the electrolyte that occurs in the battery, and it can eliminate the decrease in battery capacity due to deterioration of the lower part of the electrode plate.

FIG. 2 is a graph showing the effectiveness of the product of the present invention in eliminating the difference in a by intentionally creating a concentration difference in the electrolyte in a sealed lead-acid battery of the present invention having a capacity of 150 Ah and a plate height of 20 cm. Electrode type hydrometers were attached to the electrode plate upper central part A1 and lower part C of the electrode plate, and changes over time in specific gravity at each point of the electrode plate were investigated. From the figure, it can be seen that in the sealed lead-acid battery according to the present invention, even if an extreme difference in electrolyte temperature occurs within the battery, it can be completely removed within two days.

On the other hand, in the conventional sealed lead-acid battery, as shown in FIG. 3, the 11 degree difference was hardly eliminated even after being left for 10 days.

Effects of the Invention As described above, the sealed lead-acid battery of the present invention has the advantage that even if a difference in electrolyte concentration occurs within the battery, it can be quickly resolved.

[Brief explanation of drawings]

Figure 1 shows the main parts of the sealed lead-acid 'M'iFj pond of the present invention! 1IIS side view, FIGS. 2 and 3 respectively show the effect of eliminating the difference in electrolyte temperature between the present invention and the conventional sealed lead-acid battery. DESCRIPTION OF SYMBOLS 1... Positive electrode plate, 2... Negative electrode plate, 3... Porous separator, 4... Thin tube, 5... Pump, 6... Tube for electrolyte outflow 1 Figure aT' tI

Claims (1)

[Claims] 1. In a battery that has a structure in which most of the electrolyte is absorbed and retained in the positive electrode plate, negative electrode plate, and porous separator, the tip of a thin tube is placed inside the porous separator, and the other tip is depressurized to form a porous A sealed lead-acid battery in which the electrolyte in the upper part of the battery can be transferred to the lower part or vice versa by sucking up the electrolyte in the separator.