JPS6050858A - Injection method of sealed type lead storage battery - Google Patents

Abstract

PURPOSE:To ease retaining of electrolytic liquid in plate groups and improve battery efficiency by injecting dilute sulfuric acid again in such a condition that internal pressure of a battery is greater than the atmospheric pressure after injecting the dilute sulfuric acid into the battery. CONSTITUTION:Using paste type positive plate and negative plate that have already been charged, the positive plate and the negative plate are piled up alternately through fine fiber of minute glass and they are accommodated in an electric tank. Before fitting a seal valve to this battery, dilute sulfuric acid is injected under the normal pressure in such a condition that there is no free electrolytic liquid. After 5min since the injection dilute sulfuric acid is injected again by an injection jig capable of measuring the inside pressure of a battery to the extent that the free electrolytic liquid does not flow out as visually observing in such a condition that the internal pressure is greater than the atmospheric pressure. Thereafter the injection jig is removed and the internal pressure of battery is returned to the normal pressure, and a seal valve is fitted and the first charging is performed. Thereby, discharging efficiency is improved corresponding to the internal pressure at the time of second injection and further, the second injection volume of the electrolytic liquid is approximately correlative to the internal pressure at the time of second injection. Thus, retaining of the electrolytic liquid on the plate group becomes easy and the battery performance is improved.

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the method of injecting electrolyte into a sealed lead-acid battery, and its purpose is to facilitate the retention of electrolyte in the holes of the electrode group. .

Conventionally, the electrolyte in this type of battery is substantially non-fluidized. A known method for making the electrolyte non-fluid is to make silica colloid or fine glass fibers into a mat and use them as a support for the electrolyte. In particular, the use of fine glass fibers is easy to manufacture and therefore has utility as an alternative to silica colloids.

Generally, in this type of battery, as mentioned above, by making the electrolyte substantially non-fluidized, the oxygen gas generated from the anode plate during charging is diffused through the pores in the electrode plate group, and the electrolyte is made to be substantially non-fluidized. Since lead sulfate and water are produced by contact with the spongy lead of the cathode plate, there is almost no loss of electrolyte, making it maintenance-free.

However, in the manufacturing process of this type of battery that conventionally uses fine glass fiber as an electrolyte holder, when injecting dilute sulfuric acid, which is an electrolyte, into a battery assembled using a charged anode plate and a cathode plate, the anode A large amount of air bubbles are generated in the cathode plate and the electrolyte holder, and some of the air bubbles are discharged into the atmosphere from the exhaust plug of the storage battery. There are quite a lot of bubbles left in the body after injection, and the electrolyte remains in areas that could normally hold it, making it impossible to completely hold the electrolyte inside the battery, leading to discharge. However, it has been difficult to secure the necessary amount of dilute sulfuric acid.

In view of the above points, the present invention has investigated the relationship between battery internal resistance, electrolyte amount, or battery internal pressure, and electrolyte retention amount, etc., and found that after injecting dilute sulfuric acid into the battery, the battery internal pressure exceeds atmospheric pressure. By re-injecting dilute sulfuric acid under this condition, an amount of electrolyte that is about 10 to 15 times larger than the amount injected using the conventional method can be injected, and when the pressure is returned to normal, air bubbles in the electrode plate group are also eliminated. This is due to the discovery of the phenomenon that it is easy to remove.

In the present invention, by setting the volume (Vo) of the bubbles remaining in the electrode plate group to a pressure (P, ) higher than atmospheric pressure after electrolyte injection, the bubbles remaining under the volume pressure of P, The bubbles allow the electrolyte to permeate and hold the electrolyte in areas where it was previously impossible to hold the electrolyte. As a result, it becomes possible to hold more electrolyte than the amount that can be injected under atmospheric pressure.

Moreover, as an additional effect of the present invention, when the pressure is returned to normal pressure after applying pressure higher than atmospheric pressure, the volume of air bubbles remaining in the electrode plate group increases, but the volume of air bubbles remaining at normal pressure increases. It was found that approximately 80% of the volume of the battery was dissipated to the outside of the battery when the pressure was returned to normal.

This is considered to be because when dilute sulfuric acid was re-injected with the internal capacity of the battery at atmospheric pressure or higher, the retained electrolyte became wet, making it easier for bubbles to escape outside the electrode group.

Next, one embodiment of the present invention will be described.

According to the usual method, a charged paste-type anode plate (height 125
m, il I+ (1+I+, thickness 1.8×) cathode plate (
Height: 125mm, medium: 110mm, thickness: 1.6urn)
Using 4 anode plates and 5 cathode plates, fine glass fibers (average diameter 0.75μ, basis weight, 228.9/rn
', thickness 1.42m (at 20Kp/a-pressurized), maximum pore diameter 16μ, moisture content 87), stacked and stored in a battery case 5 pieces of 2%V batteries A I = JK 5 was manufactured. A sealing valve was attached to the JK I-&5 battery, and electrolyte was injected into each cell to the extent that free electrolyte did not come out from the electrode plate group. Approximately 235 cc of dilute sulfuric acid could be injected into all of battery cases 1 to A5.

Battery flat 1 was charged for the first time by attaching a sealing valve (Neonalene rubber, Bunsen type with a hardness of 50) after injecting liquid according to the conventional method.

Battery A2-Arashi 5 was visually observed in different states of the internal cell to the extent that no free electrolyte came out using a liquid injection jig that could measure the internal pressure of the battery after 5 minutes of liquid injection. While doing so, dilute sulfuric acid was re-injected using a syringe.

After injecting the liquid, the injection jig was removed, the pressure inside the battery was returned to normal pressure, a sealing valve was attached, and the first charge was performed under the same conditions as the battery AI.

After the initial charge was completed, the battery was left for 1 hour and then discharged to a final voltage of 1.75 V/cell at 25° C. for 5 hours to determine the discharge duration.

Furthermore, after recovery charging with a constant voltage of 2.5V per cell -
After standing at 15°C for 18 hours and discharging at 300A, the final voltage was 1. The discharge duration up to Ov was determined.

Table 1 shows the discharge test results for Battery & 1- & 5, and for Battery Arashi 2 to 5, the internal pressure at the time of re-injection and the amount of re-injection that was possible.

5-6 - As is clear from Table 1 above, compared to the conventional lead acid battery 1, the lead acid batteries 2 to 55 according to the present invention have a discharge performance equivalent to the internal pressure at the time of refilling and are more effective.

As described above, the present invention has great industrial value, such as facilitating retention of electrolyte in the electrode plate group and improving battery performance.

patent applicant 7-

Claims (1)

[Claims] A method for filling a sealed lead-acid battery, which comprises injecting the electrolyte into the battery and then re-filling the electrolyte while keeping the internal pressure of the battery at or above atmospheric pressure.