JPH0128624Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a separator for a sealed lead-acid battery.

Conventional non-leakage, sealed lead-acid batteries are Pb or Pb
-Using a Ca-based alloy as the lattice body and using a mat-shaped glass fiber with a narrow diameter as the separator,
It is a battery with an extremely small amount of liquid, in which the separator is simply impregnated with an aqueous sulfuric acid solution having a specific gravity of about 1300 to 1350 as an electrolyte. Therefore, this battery has a sealed structure, since there is no risk of liquid leakage, and oxygen gas generated from the anode during charging moves to the cathode and is absorbed by the cathode plate by the following sealing reaction. It has excellent characteristics that make it possible to

1/20 ₂ +Pb=PbO PbO+H ₂ SO ₄ =PbSO ₄ +H ₂ O However, in this battery, the electrolyte is also retained in the separator, which is a dense collection of glass fibers, using capillary action. Therefore, when the electrode is made larger, the electrolyte moves as the battery is repeatedly charged and discharged, and the amount of electrolyte retained in the upper part of the separator in contact with the electrode decreases compared to the lower part. concentration becomes lower. Due to this distribution of the electrolyte, the electrolyte necessary for the discharge reaction cannot be secured in the upper part of the electrode, which is near the current collector terminal and has the lowest electrical resistance, resulting in significantly poor high-rate discharge characteristics. . In order to solve this drawback, a proposal has been made to use a separator in which glass fiber is filled in a resin frame provided with partitions for partitioning into a plurality of chambers. According to this proposal, the electrolyte is impregnated into the filled glass fibers, but since the electrolyte is partitioned between the partitions so that there is virtually no movement of the electrolyte, the glass fibers in each room are The impregnated electrolyte is used only within the chamber, and an almost even amount of electrolyte is retained over the entire surface of the separator, reducing the concentration distribution of the electrolyte, making it possible to make the electrode larger. It is said that the high rate discharge characteristics can be improved when

However, even in batteries using the separator proposed above, when the electrodes are made larger like in conventional batteries, the oxygen gas generated from the anode during overcharging of the battery does not come into contact with the separator, and the battery It easily diffuses to the periphery of the cathode plate exposed to the internal space, and the sealing reaction occurs concentrated at the periphery, resulting in excessive lead sulfate formation. Therefore, even after charging, lead sulfate that is not reduced to lead remains and accumulates (sulfation), resulting in a problem in which the capacity involved in charging and discharging of the cathode plate decreases. In addition, the reduction in the capacity of the cathode plate causes the generation of oxygen gas at the anode and hydrogen gas at the cathode, resulting in a problem of loss of water in the electrolyte.

Therefore, the purpose of the present invention is to eliminate the above drawbacks and
In order to improve the above-mentioned high rate discharge characteristics, a separator for a sealed lead-acid battery is provided that allows the sealing reaction to occur over the entire surface of the cathode plate, resulting in less liquid loss and a reduction in cathode plate capacity. It is about providing. The key point of the present invention is to provide a partition that divides the interior of the resin frame into multiple chambers, and to maintain air permeability between the electrodes in the resin frame and the partition in the isolator in which the interior of the chamber is filled with glass fiber. The point is that it has a plurality of holes for

The hole must pass through the cathode plate side and the anode plate side of the separator. Since most of the electrolyte is impregnated into the filled glass fibers, the pores contain almost no electrolyte. Therefore, oxygen gas generated at the anode plate during overcharging can easily move to the cathode plate through the plurality of through holes provided in the resin frame of the separator and the plurality of partition bars, and the sealed reaction occurs. Since it is absorbed by the cathode plate, the hermetic reaction is no longer unevenly distributed at the periphery of the cathode plate as described above. Furthermore, in order to cause the sealing reaction to occur over the entire surface of the cathode plate, it is desirable that the holes be provided evenly throughout the resin frame and the partitions, and it is also effective to partition them as finely as possible.

By using the above-mentioned separator, a leak-free, sealed lead-acid battery with less liquid loss during overcharging and less reduction in cathode plate capacity due to sulfation can be obtained.

Next, an example of the present invention will be explained.

1 is a resin frame, 2 is glass fiber, and 3 is a hole provided in the resin frame 1 and the partition 4 to maintain air permeability. As shown in FIG. 1, a circular hole 3 is provided in the partition 4 of the resin frame 1, and the hole 3 is formed between the resin frame 1 and the partition 4 as shown in FIG. penetrates through. The resin frame 1 and the partition rod 4 having such holes 3 can be easily obtained by integrally molding acid-resistant polypropylene, ABS resin, or the like by injection molding or punching a resin plate.

The cycle life of a sealed battery using the separator 5 having the structure shown in FIG. 1 was measured. The resin frame 1 is a 2.0mm thick polypropylene board (W127mm x H148
mm) is the thickness of partition 4 and is 2.0mm, and the inner diameter is W19mm.
I used a piece cut out to be xH19mm. Glass fiber 2 has a diameter of 1 μm and is made into a mat shape using a binder, then cut into a size of W19 mm x H19 mm.
Each chamber in the resin frame 1 was filled with the resin. The thickness of glass fiber 2 is 20Kg/dm ² The thickness of glass fiber 2 is 1.0mm under load.
I used it in layers. Hole 3 is circular (diameter 1.0mm)
They were installed on partition rack 4 at 5.0 mm intervals.

The anode plate and cathode plate (both W105mm x H125mm) were made according to the usual method, but the thickness of the anode plate was 2.0mm.
The thickness of the cathode plate is 1.4 mm. The structure of the battery is an electrode plate group in which separators 5 according to the present invention are placed on both sides of one anode plate, and one cathode plate is placed on the outside of the separator 5. A load of ² is applied. 95 ml of sulfuric acid electrolyte with a specific gravity of 1.345 was poured into this battery. For comparison, a battery was also fabricated using only an electrode plate obtained under the same conditions and a glass mat (W 127 mm x H 148 mm) as a separator. The injection volume in this case is 99ml. After each battery was sealed, it was charged at a constant voltage of 14.7V (limited to 5A) for 8 hours to bring it to a fully charged state.

The cycle life characteristics of these batteries were compared. The cycle conditions were a constant discharge of 6.6A until the battery voltage reached 1.75V. Charging is under the same conditions as described above. Figure 3 shows the change in capacity with respect to cycles. Battery A using the separator 5 according to the invention clearly has a better cycle life than battery B using a separator made of glass mat only. The main cause of battery B's life span is sulfation of the cathode plate, and when the separator 5 of the present invention is used, the oxygen gas generated during charging on the anode plate is absorbed by the entire surface of the cathode plate, so that the sulfation of the cathode plate is the main cause. It is thought that the capacity drop of the cathode plate is small and the cycle life is excellent.

As mentioned above, the present invention has great practical value, such as preventing capacity reduction due to sulfation of the cathode plate of lead-acid batteries and improving cycle life.

[Brief explanation of the drawing]

Fig. 1 is a front configuration diagram of the separator according to the present invention, Fig. 2 is a cross-sectional view of the separator along the line A-A' in Fig. 1, and Fig. 3 shows the number of cycles of the battery according to the present invention and the conventional battery. It is a curve diagram showing the relationship with battery capacity. 1 is a resin frame, 2 is a glass fiber, 3 is a hole, 4
5 is a partition, and 5 is an isolation body.

Claims (1)

[Scope of utility model registration request] A closed type, in which a partition rod is provided to partition the inside of a resin frame into a plurality of chambers, the chambers are filled with glass fiber, and a plurality of through holes reaching the electrode surface are provided in the resin frame and the partition rod. Separator for lead-acid batteries.