Rechargeable battery

Disclosed is a rechargeable battery for preventing a short circuit of a cell by inducing bending of a case under compression. The rechargeable battery comprises a case comprising a bottom portion and front and rear portions connected to the bottom portion by joint portions including internal curved surfaces, an electrode assembly in the case and a cap assembly closing the case, wherein the curved surfaces define a first portion A1 in a centre portion of the case and second portions A2 on either side of the first portion, wherein the second portions have a higher mechanical strength than the first portion with respect to a compression force applied to the sides of the case.