Patent ID: 9564614
Date: 2017-02-07
CPC Classifications: B32B,H01M,Y02E

Claim:
1. A secondary battery comprising: an electrode assembly; a case receiving the electrode assembly and including a plurality of stepped sections at an inner side of the case in contact with the electrode assembly; and at least one electrode tab electrically connected with the electrode assembly and withdrawn toward an outside of the case in a first direction, wherein the case includes a receiving section receiving the electrode assembly, and a cover section covering the electrode assembly, wherein the receiving section includes a bottom section, a side wall section extending from the bottom section, and a junction section extending from upper end section of the side wall section, wherein the junction section and the cover section are coupled to each other, wherein the electrode assembly comprises a pair of first sides extending in the first direction, being spaced apart in a second direction, and facing the bottom section and the cover section, respectively, and a pair of second sides extending in the first direction and facing opposite sides of the side wall section, respectively, the first sides being larger than the second sides, wherein the bottom section comprises at least a first layer contacting the electrode assembly, and stepped sections of the plurality of stepped sections are at a surface of the first layer facing the cover section and being in direct contact with a first side of the pair of first sides of the electrode assembly, and wherein the stepped sections are defined by a plurality of openings in the first layer such that a thickness in the second direction of the first layer at a stepped section of the stepped sections is less than a thickness in the second direction of the first layer at a region of the bottom section adjacent the stepped section.