JPS58100359A - Manufacture of battery and its electrode - Google Patents

Abstract

PURPOSE:To make a lead plate to be securely connected to the end surface of a spirally rolled electrode plate by constituting the peripheral part of the electrode plate, which works as a lead-connecting part, of the compressed part of a compressed spongy metallic base plate and a flexible resin which is pressed upon said compressed part. CONSTITUTION:The symbol 13 represents a long spongy nickel base plate. After parts of the plate 13 which extend perpendicularly to the longitudinal direction of the plate 13 are compressed so as to form grooves 14, thin resin plates 15 are applied inside the grooves 14, and molten by pressure heating so as to pack most part of the resin into the compressed parts 16 of the plate 13 which form the bottoms of the grooves 14. Next, after packing of an active material and pressure molding process of the packed body are finished, the plate 13 is cut at the centers of the grooves 14 as well as at the centers between the grooves 14. In a positive electrode prepared in such a manner as above, each compressed part 16 of the plate 13 works as a terminal part 2a, which is welded to a lead plate. Therefore, the end surface of the terminal part 2a is a cut surface, and a nickel bone which constitutes the spongy base plate 13 is exposed at the cut surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in the 17-nid connections of electrodes in cylindrical batteries such as nickel-cadmium storage batteries.

Recently, various devices have become cordless, and alkaline storage batteries, especially sealed cylindrical nickel-cadmium storage batteries, have begun to be widely used as power supplies for various devices that require relatively high output and high reliability, and for disaster prevention. There is.

The positive electrode of this battery generally uses a sintered type electrode, and the negative electrode uses both a sintered type and a non-sintered type. In any of the electrodes, a core material such as a sintered substrate (with a metal core placed inside the substrate) or a perforated plate is used as the electrode support.

The positive and negative electrodes are wound in a spiral shape through a separator.The electrode leads can be taken out from this electrode group by welding the lead plate directly to the electrodes, or by attaching the cores to both ends of the electrode group. A method is used in which the lead plate is connected to the electrode by exposing the gold or the like, applying a lead plate to the exposed area, and welding the entire end of the spiral electrode. In the latter case, there are many contact points between the electrode and the lead plate, and this method is suitable for high rate discharge.

Various proposals regarding this have been made.

Recently, in addition to the above-mentioned electrodes, electrodes using a porous sponge-like metal material having high porosity as a substrate have been proposed. Basically, this electrode can be obtained by, for example, filling a sponge-like porous nickel material with nickel hydroxide powder, which is an active material, in a paste form, and then molding the material by 8E. The manufacturing process is simpler than sintered electrodes.
"T: Yes, and has characteristics such as high active material packing density.

However, this electrode has a problem in that it is difficult to weld to the lead plate. In particular, in the latter method of welding the lead plate to the entire end face of the spirally wound electrode plate, in addition to the fact that the amount of metal in the sponge-like substrate itself is small, the welded part of the lead plate is compressed under pressure. The strength is improved to some extent, but unlike the essentially uniform metal plates such as the core metal used in sintered and based methods, if the lead plate is pressed too hard against the edge of the electrode plate, the area to be welded will bend. There is a problem of insufficient strength. Furthermore, if welding is performed simply by applying pressure to the lead plate without applying pressure, the contact resistance during welding will increase and the substrate in the area to be welded will be melted away.

The present invention solves the above-mentioned problems when using a sponge-like metal porous body as a substrate, and ensures reliable connection of a lead plate to the end face of a spirally wound electrode plate.

That is, the present invention includes a compressed portion formed by pressurizing and compressing a sponge-like metal substrate at an edge portion constituting a lead connection portion of an electrode plate;
It is made of flexible resin that is crimped here. It is preferable to fill this resin into one compressed part of the substrate by heating and melting it. Note that if a non-flexible material such as epoxy resin is used, it may break when the electrode plate is wound into a spiral shape. occurs, and the strength decreases.

The present invention will be explained below using examples.

Porosity 94% 2 weight density eony/crti* A long band-shaped sponge-like nickel substrate with a thickness of approximately 1.10 m is pressed with a pressure of 100 Kg/crA to form a width of 2 a perpendicular to the longitudinal direction of the substrate. , a groove with a depth of α97 is provided. Next, a polypropylene plate having a width of 2 meters and a thickness of 021 meters is placed in this groove and heated and melted to fill the inside of the substrate pressing section with resin. Next, the entire substrate is filled with a paste of active material powder mainly consisting of nickel hydroxide powder, and the active material adhering to the surface of the groove is polished and removed. The entire electrode plate is then pressure molded and dried. Next, cut the center of the groove and the center between the grooves to obtain a width of 38 mm and a length of 2101 rI.
! An electrode with a thickness of 0.7° (the pressurized edge is α16 mm) is obtained.

This positive electrode and a general-purpose cadmium negative electrode with a length of 260cm and a thickness of 055mm are made of polyamide nonwoven fabric. Wrap it in a spiral shape and secure it by wrapping polyethylene tape around the outer periphery. In this case, the edges of the upper and negative electrodes are exposed at the top and bottom of the electrode.Next, disk-shaped nickel lead plates with a smaller diameter than the electrode group are placed above and below the electrode group. are applied and welded to the edges of the positive and negative electrodes, respectively.In this case, each welding point is approximately 40 points.

Figure 1 shows a cylindrical sealed nickel battery using the above electrode plate group.
The schematic configuration of a cadmium storage battery is shown. 1 is a group of electrode plates, 2 is a positive electrode, 3 is a negative electrode, 4 is a 7) electrode, and edge portions 2a and 3ald of the positive and negative electrodes exposed above and below the electrode group, respectively, lead plates 6, It is welded to 6. 7 is a metal case that also serves as a negative electrode terminal, and a lead plate 6 on the negative electrode side is attached to the bottom of the metal case.
The center is welded. Reference numeral 8 denotes a metal sealing plate, which is connected to the lead plate 6 on the IE pole side by a lead piece 9, and forms a safety valve by closing a through hole provided in the center with a rubber valve. 11 is a positive electrode terminal cap and 121'i gasket.

2 to 4 schematically show the manufacturing process of the positive electrode. 13
is a long sponge-like nickel substrate, after forming grooves 14 by pressing and compressing it in a direction perpendicular to the longitudinal direction, a thin resin plate 16 is placed in the groove 14, and the resin plate is melted by pressure heating.
The compressed portion 16 of the substrate forming the bottom of the groove is filled with most of the resin.

Next, after filling the active material and pressurizing the molding process, the groove 14 is formed.
Cut the center part of the groove and the center between the grooves.

In the positive electrode thus obtained, the compressed portion 16 of the substrate constitutes the edge portion 2a to be welded to the lead plate, the end surface is the above-mentioned cut surface, and the nickel skeleton constituting the sponge-like substrate is exposed.

A disc-shaped lead plate was placed on the edge of the positive electrode according to the above practical example, and the strength until the edge bent was measured.
It showed about 7 μm. On the other hand, in the case where the edge portions were not reinforced with resin as described above, the power consumption was about 25 KW/cm 2 . Furthermore, regarding the weight density of 40 to 100 kg, which is generally used as a sponge-like porous material for use in substrates, the structure according to the present invention has a strength exceeding the generally required strength of about 6 Kq/crn. was. Furthermore, the tensile strength of the welded lead plate is approximately TK.
y, indicating sufficient welding strength.

In the above embodiment, the resin f was heated and infiltrated into the compressed edge of the substrate to which the lead plate is to be welded, but it is also possible to simply pressurize the resin and fill it with molten resin. Suitable resins to be used include polypropylene, polyethylene, and the like. In addition, the present invention is not limited to the nickel positive electrode, and can be applied to any case where a sponge-like metal porous body is used as the substrate and a cylindrical shape (winding is adopted to form an electrode plate group configuration).

As described above, the present invention enables a strong connection between the electrode terminal portion and the lead plate when a sponge-like metal porous material is used for the electrode substrate in a battery that requires characteristics such as rapid discharge. It is meant to be.

[Brief explanation of drawings]

FIG.
The figure is a schematic vertical cross-sectional view showing the manufacturing process of the edge portion of the substrate. 1... Electrode plate group, 2... Positive electrode, 3...
・-・Negative electrode, 4...Separator, 2a, 3a*
...Edge, 131III@...Substrate, 14
...Groove, 15-...Resin plate, 16...
...Compression section. Name of agent: Patent attorney Toshio Nakao and one other person II
Figure 1j Figure 2

Claims (2)

[Claims] (1) A positive electrode and a negative electrode are wound through a separator,
an electrode group in which at least one edge of the electrode is exposed in the direction of the winding axis; and a lead plate extending substantially perpendicular to the axis direction and having the exposed electrode edge welded to the surface thereof. and wherein the one electrode is composed of a sponge-like porous metal substrate and an active material filled therein, and an edge portion to be welded to the lead plate is crimped to a compressed portion of the substrate. A battery characterized in that the metal part of the substrate is exposed at the end face. (2) A step of forming a band-shaped pressurized compressed part on a long sponge-like porous metal substrate in a direction substantially perpendicular to the longitudinal force thereof, a step of crimping a flexible resin to the compressed part, A battery characterized in that an electrode having the cut surface as a welded part with a lead plate is obtained by a step of filling the substrate with a substance and press-molding it, and a step of cutting approximately the center of the pressurized part. Method of manufacturing electrodes for use.