JPS6031159Y2 - alkaline storage battery - Google Patents

Description

[Detailed description of the invention] This invention is based on an alkali structure in which current collectors are welded to the upper and lower edges of a spiral electrode body consisting of band-shaped positive and negative polar plates and a separator inserted between these polar plates. This relates to improvements in storage batteries.

A spiral electrode body, for example, an electrode body of a cylindrical nickel-cadmium storage battery, as shown in FIG. It is formed by winding it into a spiral.

From the viewpoint of improving high rate discharge characteristics, the current collecting method is to shift the ends of the anode plate 1 and cathode plate 2 in the vertical direction, respectively, to make the edges protrude above and below the electrode body, and to collect the current collector there. 4.5 is welded.

In the figure, 6 is a battery case that also serves as a cathode terminal, 7 is an anode terminal cap, and 8 is a gasket interposed between the battery case and the sealing plate 7a.

As shown in FIG. 2, the current collector 5 of one electrode, e.g. It consists of
It consists of a flat plate punched from a thin nickel-plated steel plate.

The connection with the edge of the electrode body is made by bringing the current collecting part 5-2 of the current collector 5 into contact with the upper end surface of the electrode body as shown by the dotted line in FIG. Welding electrodes 10 were brought into contact with each other, and current was applied between the electrodes to weld the upper end surface 9 of the electrode body and the current collecting portion 5-2 of the current collector 5.

In this case, when the current collecting portion 5-2' of the current collector 5 located between the pair of welding electrodes 10 is fused due to the heat generated during welding, the welding strength is sufficient to withstand a tensile strength of 5 to 9 or more. In the case of no melting, the strength was only around 3 kp, which resulted in insufficient welding strength, resulting in an increase in internal resistance of the battery and dislocation of welding, making it impossible to satisfy the battery's function.

Therefore, in order to ensure sufficient welding strength, the current collecting portion 5 of the current collector 5 located between the pair of welding electrodes 10 as described above is
-2' was cut and welded.

Reference numeral 11-2.11-2.11-3 in FIG. 3 shows the fusing portion of the current collecting portion 5-2'.

However, in such a welded structure, the fusion cross section becomes unstable due to changes in various conditions such as the distance between the electrodes and wear, and the fusion section 11-1.11-2.1 shown in FIG. 3 becomes unstable.
As shown in 1-3, the size and shape vary,
In the fusing part 11-1, which has a particularly large fusing cross-sectional area, as shown in FIG. There was a drawback that the battery could not be sufficiently isolated from the cathode plate 2, and the melted fragments often connected the positive and negative picture electrodes, causing internal short circuits and failing to function as a battery.

The present invention is characterized in that, in order to prevent internal short-circuit defects caused by the above-mentioned melted fragments, the current collector is provided with a thin wall portion extending radially from the center of the current collector, particularly in the approximately disk-shaped current collecting portion. An example of this will be described below.

FIG. 4 shows the current collector 5 of the present invention.

This current collector 5 has a lead-out portion 5- for connection to an external terminal.
3 and a substantially disk-shaped current collecting portion 5-2, the current collecting portion 5
-2 has a circular through hole 5-1 in the center and omit three wedge-shaped linear protrusions 5-4 radially spaced at 120° intervals from the center of the through hole 5-1.

This linear protrusion 5-4 has a sharp tip, and the entire protrusion 5-4 is formed thinner than the thickness of the current collecting portion 5-2, and the resistance value of this protrusion 5-4 is The current collecting part 5
The resistance value is set higher than -2 to facilitate fusing during welding, to reduce the fusing cross-sectional area, and to make the fusing shape constant.

Using this current collector plate, the current collector 5 and the electrode body are welded by the method shown in FIGS. 5 and 6.

The current collecting portion 5-2 of the current collector 5 is brought into contact with the upper end surface 9 of the electrode body shown by the dotted line in FIG. This wedge-shaped linear protrusion 5-4 is positioned between a pair of welding electrodes 10, and the welding electrode 1
0 is brought into contact with both left and right sides of the linear protrusion, and current is applied to the electrode 10 to weld the current collecting portion 5-2' of the current collector 5 and the upper end surface 9 of the electrode body shown by the dotted line.

Due to this structure, the melting surface 12 is linear, constant, and narrow, and melted fragments are hardly generated, and even if they are generated, they are extremely small, so that the internal space between the electrodes due to melted fragments as shown in the conventional example is No short circuit occurs.

The following table shows the welding strength and the percentage of defective batteries due to melted fragments of internally shorted batteries between the conventional product and the product of the present invention, both of which show that the product of the present invention has better results.

As described above, the present invention provides a current collector structure that is extremely effective in terms of battery quality.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a cylindrical nickel-cadmium storage battery.
FIG. 2 is a plan view of a conventional current collector, FIG. 3 is a diagram showing a welded state of a conventional current collector, FIG. 4 is a plan view of a current collector in an embodiment of the present invention, and FIG. 5 6 is an explanatory view taken along the v-v' line in FIG. 4 when the current collector is welded, and FIG. 6 is a plan view showing the welded state of the current collector. 1... Anode plate, 2... Cathode plate, 3...
... Separator, 4-5 ... Current collector, 5-
1... Circular through hole, 5-2... Approximately disk-shaped current collecting part, 5-3... Derivation part, 5-4...
... Linear protrusion (thin wall part), 6 ... Battery case, 7a ... Sealing body, 8 ... Gasket, 9 ... Electrode body Upper end surface, 10...pair of welding electrodes, 12...melting section.

Claims (1)

[Scope of utility model registration request] In an electrode body structure in which a current collector is welded to the edge of a spiral electrode body consisting of band-shaped positive and negative polar plates and a separator inserted between them, the current collecting portion of the current collector is What is claimed is: 1. An alkaline storage battery characterized by having a substantially disk-like shape with a through hole in the center and a thin wall portion consisting of wedge-shaped linear protrusions extending radially from the center of the through hole.