JPH01187761A - Sealed lead acid battery - Google Patents

Abstract

PURPOSE:To eliminate breakage of a contractive tube and enhance the reliability by spot welding a metal foil or metal plate to a metal plate constituting the electricity collector of each cell, and thereby connecting the cells. CONSTITUTION:A frame 5 is welded to the peripheries of tinned steel plates 7, 7' formed from a copolymer film 6 of ethylene and acrylic acid laminated on the internal surface in contact with a group 4 of electrode plates 4, followed by sealing, and nails 9, 9' of these metal plates 7, 7' are welded with electrode plate tabs 8, 8' to make the metal plates 7, 7, as an electricity collector, and a safety valve 10 is mounted to part of the framing 5 to provide a cell 11. A Cu foil 15 is attached to adjoining metal plates 7, 7'' of different polarities by placing three such cells side by side and electrically connected by spot welding by a pair of welding electrodes 16, 16', and cells arranged on the same surface are fixed by an adhesive tape 13 followed by covering with a thermocontractive tube 14. Thus a battery is accomplished. This minimizes thermal influence upon the frame and the film laminated on the inside surface of metal plate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in the cell-to-cell connection or terminal extraction structure of a sealed lead-acid battery used as a power source for portable devices and the like.

BACKGROUND OF THE INVENTION Conventionally, this type of sealed lead-acid battery has a structure in which an electrode group 4 consisting of a positive electrode plate 1, a negative electrode plate 2, and a separator 3 is surrounded by a frame 6 made of polyethylene, as shown in FIG. The two peripheries of the tin plated steel plates 7 and 7' are welded and sealed with the frame 5, and the edges of the positive and negative electrode plates are sealed. The metal plate γ is formed by welding the portion 8°8′ and the claw portion 9.9′ of the metal plate.

7' was used as a current collector power terminal, and a safety valve 10 was attached to the frame 6 to form a cell/I/11. In addition, when arranging a plurality of cells on the same surface and integrating them, solder the metal plates 7.7" of different polarities of adjacent cells using lead wires 12 as shown in FIG. The cells were then electrically connected, the cells were fixed with adhesive tape 13, and a heat-shrinkable tube 14 was covered as shown in FIG. 6 to produce a product.

Note that '+' is a lead wire for 2 electric terminals.

Problems to be Solved by the Invention However, when soldering lead wires like this, ■ Even if the cell itself is thin, the T-cell thickness becomes substantially thicker due to the thickness of the lead wire and the swelling of the solder. The heat-shrinkable tube is torn due to cracks and whiskers,■
Soldering has problems such as damage to the film on the inner surface of the metal plates 7 and 7'' due to the heat of time, and the heat welded portions to the frame coming off.

Means for Solving the Problems In order to solve this problem, the present invention connects the cells by spot welding a metal foil or a metal plate to the metal plate forming the current collector of the cells.

It is possible to weld in a short time by minimizing the heat effect on the film laminated on the inner surface of the metal plate and the frame without the generation of whiskers at the welding part that harm the working part.

Example An embodiment of the present invention will be described below based on the drawings.

The present invention has a positive electrode plate 1 as shown in FIG.
, an electrode plate group 4 consisting of a negative electrode plate 2 and a separator 3 is surrounded by a frame 5 made of polyethylene, and the inner surface in contact with the electrode plate group 4 is laminated with a lithium-ion composite film 6 of ethylene and acrylic acid. 'The peripheral edges of the two sheets and the frame body 6 are sealed by heat welding, and the electrode plate ears 8, 8' and the metal plate 7 are sealed.
．． The metal plate 7.7' is used as a current collecting part by welding the claw part 9.9' of γ', and the safety valve 10 is attached to a part of the frame 5 to form a ce/l/11, as shown in Fig. 1. 3 cells are arranged side by side and adjacent metal plates 7, 7” with a thickness of 35μ width eM
Copper foil 16 with a TI length of 20III is pasted and electrically connected by spot welding using a pair of welding electrodes 16 and 16' as shown in FIG. 2, and placed on the same surface using adhesive tape 13. The cells thus prepared were fixed together and covered with a heat-shrinkable tube 14 as shown in FIG. 3 to form a battery.

Generally, in the case of spot welding, metals of the same series, such as copper and brass, or iron and nickel, are easy to weld because their melting points and resistances are close. Therefore, it is easy to spot weld a nickel plate to a tin plated steel plate, and since welding can be performed in a short time of about 1/6 o seconds, there is almost no thermal effect on the film on the back of the metal plate. It was also confirmed that in a combination of a tin plated steel plate and copper, if the copper is made into a foil with a thickness of 35Ixn, if the copper is instantaneously heated in a short time of 1/60 seconds, it can be welded to the tin plated steel plate without heat dissipation. Also, since copper has a lower electrical resistance than nickel, it has the advantage of being able to be made thinner.

Now, as a result of measuring the fusing current when a copper foil having a thickness of 35 μm and a width of 6 mm is used as an inter-cell connector, it was found to be 100 A or more, and it was found that there was no particular problem in practical use.

Effects of the Invention As described above, according to the present invention, by using a foil or metal plate as the inter-cell connection body and reducing its thickness, the outward protrusion after the inter-cell connection is reduced, thereby eliminating damage to the shrinkable tube and increasing reliability. This makes it possible to provide a battery with high battery life.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an assembled state of sealed lead-acid batteries according to an embodiment of the present invention, FIG. 2 is a sectional view of a spot welded portion of an inter-cell connector according to the present invention, and FIG. 3 is a heat-shrinkable tube. FIG. 4 is a perspective view of the sealed lead-acid battery of the present invention packaged with a battery, FIG. 4 is a perspective view of the cell before assembly, FIG. FIG. 3 is a perspective view of the battery when it is packaged. 1... Positive electrode plate, 2... Negative electrode plate, 3...
... Separator, 4 ... Plate group, 5 ...
...Frame body, 7,7'...Metal plate, 11...
... Cell, 14 ... Heat-shrinkable tube, 16
······Copper foil. Name of agent: Patent attorney Toshio Nakao and 1 other person - Mushi, φ rumor

Claims (1)

[Claims] A positive electrode plate, a negative electrode plate, and a separator are placed inside a container consisting of a metal plate laminated with a heat-weldable synthetic resin film or sheet on one side and a heat-weldable synthetic resin frame welded to the metal plate. A sealed lead-acid battery in which a group of electrode plates is sealed and a plurality of cells are arranged on the same surface using the metal plate as a current collector, and a metal foil or a metal plate is spot welded to the metal plate to create a gap between the cells. A sealed lead-acid battery characterized by connecting.