Patent ID: 9741985
Date: 2017-08-22
CPC Classifications: B21K,H01M,Y02E

Claim:
1. A prismatic secondary battery comprising: a prismatic hollow outer body having a mouth and a bottom; a flat electrode assembly including a positive electrode sheet and a negative electrode sheet; a positive electrode collector electrically connected to the positive electrode sheet; a negative electrode collector electrically connected to the negative electrode sheet; an electrolyte; a positive electrode terminal electrically connected to the positive electrode collector; a negative electrode terminal electrically connected to the negative electrode collector; a sealing plate sealing up the mouth of the prismatic outer body, the sealing plate including a first coining area formed around the first mouth on the front face; a gas release valve and an electrolyte pour hole formed between the pair of mouths; a first long side edge; a first groove formed on the front face from a position between the first coining area and the first long side edge to a position near the gas release valve along the first long side edge of the sealing plate; a second groove formed on the front face, the second groove is formed between the second long side edge and the first coining area; a first insulating member attached to the first coining area, wherein one of the positive electrode terminal and the negative terminal electrode terminal is inserted into the first mouth; a region of the sealing plate where the first groove is formed has a thickness thinner than that of a region of the sealing plate which is located around the first groove, a region of the sealing plate where the second groove is formed has a thickness thinner than that of a region of the sealing plate which is located around the second groove, a length of the first groove in the longitudinal direction of the sealing plate is greater than a length of the first coining area in the longitudinal direction of the sealing plate; an end of the first groove which is located near to the gas release valve is arranged between the gas release valve and the electrolyte pour hole in the longitudinal direction of the sealing plate; and the first groove has a depth near the gas release valve smaller than a depth of a part of the first groove which is located between the first long side edge and the first coining area, an end of the second groove which is located near to the gas release valve is arranged between the gas release valve and the electrolyte pour hole in the longitudinal direction of the sealing plate, and the second groove has a depth near the gas release valve smaller than a depth of a part of the second groove which is located between the first long side edge and the first coining area.