RECTANGULAR BATTERY

摘要

Provided is a rectangular battery in which an electrode group (3) is housed inside a battery case (1) together with an electrolyte, wherein the electrode group (3) is configured such that a first polarity electrode plate and a second polarity electrode plate are wound with a porous insulator interposed therebetween and the battery case has a rectangular cross-sectional shape. In the rectangular battery, a lead (9L) connected to the first polarity electrode plate is connected to the battery case which is a first polarity external terminal, and another lead (11L) connected to the second polarity electrode plate is connected, through a connection plate (31) provided between the electrode group and a sealing plate (15) for sealing the opening of the battery case, to a second polarity external terminal (25) provided on the sealing plate. The rectangular battery conventionally has a problem of being deformed and generating heat when a certain load is externally applied in the long-side direction of the battery case. Especially, since a lithium secondary battery has a high energy density, there has been the problem of overheating. According to the invention, a solution for the above problem is that in the rectangular battery, the space between the battery case (1) and the connection plate (31) at at least one end in the long-side direction of the battery case is set to a half or less of the width of the battery case in the short-side direction of the battery case.