JPH03184256A - Sealed type battery - Google Patents

Abstract

PURPOSE:To enhance the electric discharging performance by arranging a hydrophobic separator in the double separator part, and thereby preventing ununiformity of electrolyte distribution in case the separator in the initial winding part is made in double structure. CONSTITUTION:A main separator 1 is made from nylon unwoven cloth, while an aux. separator 2a is made from a shorter unwoven cloth consisting of polypropylene having a lower liquid retaining property than the first named, and is constructed double partially. In lieu of polypropylene aux. separator 2a, an aux. separator 2b of nylon subjected to a water repellent processing may be used. Because this sinks the liquid retaining property, the liquid retaining property of this double part of separator does not substantially differ from the single part, which should preclude eccentric presence of electrolyte in this part to lead to enhancement of the discharge characteristic of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a seven-cell regulator for a sealed storage battery.

2. Description of the Related Art In general, the electrode plate group of a sealed alkaline storage battery is constructed by winding positive and negative electrode plates with a separator in between. 4th-
Figures a and 4-b show a method of constructing such a group of electrode plates. In FIG. 4-IL, the positive electrode plate 3 and the negative electrode plate 4 start winding at the overlapping part of the separator 6, and are wound in a spiral shape as a whole by the winding core 7. Further, Fig. 4-b shows that the positive electrode plate 3 and the negative electrode plate 4 are wound in a spiral shape using the winding core 7, starting from the overlapping part of the main separator 8 and the relatively short auxiliary separator 9. It's a method. In either case, in order to increase the strength of the separator at the beginning of winding of the electrode plate group and prevent short circuits between the positive and negative electrodes, the separator at the beginning of winding is double-layered.

Problems to be Solved by the Invention However, in these conventional examples, since the separator at the winding start part of the electrode plate group is double, a large amount of electrolyte is retained at the winding start part, and as a result, the separator in the single layer part of the electrode plate group is retained in a large amount. This resulted in a problem of non-uniform electrolyte distribution. That is, in the case of FIG. 4, as shown in the conventional example of FIG. 3, the amount of electrolyte in the portion facing the electrode plates was smaller than that of the conventional example in which the separators were not double-layered, so the discharge performance was inferior.

The present invention is intended to solve the above-mentioned problems, and is aimed at preventing non-uniform distribution of electrolyte when the separator at the beginning of winding is doubled.

Means for Solving the Problems In order to achieve this object, the present invention has made the liquid retention property of the double-overlapping part of the separator relatively low, and the difference with the liquid retention property of the mold part has been reduced. Specifically, the material of one of the separators in the double-overlapping area can be changed to a material with lower liquid retention than the other, or the separator itself can be improved by applying water-repellent treatment to the double-overlapping area of the separator. This makes a difference in the liquid retention capacity of the two.

Effect: By using such means, it is possible to prevent the electrolyte from being unevenly distributed in the double portion of the separator, to make the electrolyte distribution uniform throughout the separator, and to improve the discharge performance.

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

A first embodiment is shown in Fig. 1-a. This is made by partially doubling the main separator 1 made of nylon nonwoven fabric with auxiliary separators 2-IL and 1- made of short polypropylene nonwoven fabrics having lower liquid retention properties. In other words, by changing the auxiliary separator to a material with lower liquid retention than the main separator and overlaying it on the winding start part of the main separator, the strength of the separator double part at the winding start part is maintained and this part is strengthened. Uneven distribution of the electrolyte can be prevented. By this improvement, the amount of electrolyte per unit area of the main separator is improved as in Example 1 shown in FIG. Further, the discharge performance as a battery was as shown in Example 1 in FIG. 3, and the discharge capacity ratio was improved compared to the conventional example, especially in terms of high rate discharge.

As shown in Figure 1-b, the second embodiment uses a water-repellent nylon auxiliary binder 2-b instead of the polypropylene auxiliary binder used in the first embodiment. It was there. In this case, as in the first embodiment, the liquid retention property is reduced by the water repellent treatment, and the actual liquid retention capacity of the double part of the separator is much different from that of the single part, and the electrolyte is absorbed in this part. It can prevent uneven distribution, and the discharge performance is also the third highest.
It was improved as shown in Example 2 in the figure.

In the case of FIG. 4-a, the same effect as in the second embodiment can be obtained by applying a water repellent treatment to each end of the double layered separator.

Effects of the Invention As described above, according to the present invention, by imparting hydrophobicity by changing the separator material of the double-overlapping portion of the separator or by applying water-repellent treatment to the weighted portion, - Regardless of whether the separator is heavy or double, uneven distribution of the electrolyte in the separator can be eliminated and the discharge characteristics of the battery can be improved.

[Brief explanation of drawings]

Figures 1 (a) and (b) are diagrams showing the separator used in the embodiment of the present invention, and Figure 2 is a diagram showing the electrolyte held in the seven cell dividers of the nickel cadmium battery used in the embodiment of the present invention. A diagram showing the weight ratio of liquid volume, FIG.
FIGS. 4(a) and 4(b) are diagrams showing the structure of the electrode plate group of a conventional battery. 1... Main separator (nylon), 2-IL・
...Auxiliary separator (polypropylene), 2-b
...Auxiliary separator (nylon treated with water repellent), 3...Positive electrode plate, 4...Negative electrode plate,
5.6... separator, 7... winding core, 8... main separator, 9... auxiliary separator.

Claims (2)

[Claims] (1) In a sealed storage battery that is spirally wound with a band-shaped separator interposed between the positive and negative electrode plates and has a double separator portion at the beginning of the winding, the double separator portion is hydrophobic. A sealed storage battery characterized by having a separator arranged in it. (2) The sealed storage battery according to claim 1, wherein at least one member of the double separator portions is subjected to water-repellent treatment.