Battery pack

Abstract

A battery pack is made up of a plurality of flat prismatic batteries arranged face to face, each battery having one electrode terminal protruding from one end face in the height direction of the battery case and this end face or a side face of the battery serving as the other electrode terminal. The connector for electrically connecting adjacent prismatic batteries includes a flat part that is welded to one electrode terminal of one prismatic battery of the adjacent prismatic batteries, and a cylindrical part that is fitted onto and welded to the other electrode terminal of the other prismatic battery. The cylindrical part is formed in an attachment part that extends from the flat part through an upright part in the direction in which the batteries are aligned. The connector enables reliable electrical connection of the prismatic batteries despite possible variation in height of the electrode terminals.

Description

technical field [0001] The present invention relates to a battery pack formed by electrically connecting a plurality of prismatic cells. Background technique [0002] In recent years, as power sources for wireless devices such as mobile phones and electric tools, and hybrid cars, etc., with the reduction in size and weight of the devices, packs configured to obtain the required voltage by electrically connecting a plurality of rectangular batteries with excellent volumetric efficiency in series have been used. Batteries (often referred to as "battery modules" or "battery packs"). In a battery pack formed of such prismatic cells having excellent volumetric efficiency, there is a problem that, unlike cylindrical cells, when overlapping each other in the thickness direction, the prismatic cells used to connect two adjacent prismatic cells have a problem. The terminals are arranged close to the ground, and the connecting member for connecting the two terminals is smaller than t...

AI Technical Summary

Problems solved by technology

In a battery pack formed of such prismatic cells having excellent volumetric efficiency, there is a problem that, unlike cylindrical cells, when overlapping each other in the thickness direction, the prismatic cells used to connect two adjacent prismatic cells have a problem. The terminals are placed close to the ground, and the connection member for connecting the two terminals is smaller than the connection piece for cylindrical batteries, so it is difficult to determine the positions of the terminals and the connection member when connecting each other.

[0003] When connecting the prismatic batteries to each other, the positional relationship between the connecting parts and the cap-shaped terminals of the prismatic batteries is adjusted by holding the connecting parts with jigs or fingertips, but there is the following problem: since the connecting parts are small, it is difficult to ensure their exact position. As a result, the workability of spot welding is significantly deteriorated, and welding failure due to positional deviation of the connecting piece, or short circuit between prismatic batteries due to the falling of the connecting part from the fingertips, etc.

[0008] However, in the above-mentioned battery pack, when two adjacent rectangular batteries Ba1 are arranged so that the positive and negative electrodes cross each other and overlap each other in the thickness direction, the relative positions in the height direction of the two rectangular batteries Ba1 must be determined by Since the position offset x corresponding to the height of the cap-shaped electrode terminal 31 is set and combined, when the heights of the cap-shaped electrode terminal 31 and the plate-shaped electrode terminal 32 of the rectangular battery Ba1 vary, the connecting member 30 and the terminal 31, 32 contact becomes insufficient, so there is a possibility that the connection member 30 and the terminals 31, 32 are detached due to vibration or other poor welding.

[0009] In addition, in the case of a rectangular battery Ba2 having a shape in which the negative terminal 3 protrudes from the sealing plate 2 that seals the opening at one end of the rectangular battery case 1 as shown in FIG.

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