Secondary battery having a planarizing member

A secondary battery comprising:

• an electrode assembly comprising a first electrode plate and a second electrode plate that each have planar surfaces whereon first and second electrode active materials are formed on the planar surfaces of first and second electrode plates respectively, and first and second electrode tabs are formed, respectively, and comprising a separator having an outer end disposed between and overlapping with the first and second electrode plates, and the second electrode plate while overlapping with the first electrode plate and the second electrode plate wherein the an outer end of the separator defines a first step with and one of the first or second electrodes plate define a step, and a second step with the second electrode plate;
• and
• at least one a planarizing member disposed on a first end of the at least one of first and second ends of the electrode assembly to support the first end of the electrode assembly, that are opposite each other on the first and second electrode plates electrode assembly, wherein the planarizing member comprises a stepped form that is complementary with a stepped surface exposed on the at least one of the first and second ends between the two electrode plates comprising at least the first and second steps, wherein the at least one planarizing member has:
• an inner surface that receives the stepped surface exposed on the at least one of the first and second ends between the two electrode plates comprising at least the first and second steps, so as to cover and planarize the stepped surface, wherein the inner surface comprises accepting parts for accepting one or more stepped forms among stepped forms of edges of the first and second electrode active materials, the first and second electrode tabs, edges of the first and second electrode plates, and an edge of the separator, and
• an outer surface of the at least one planarizing member member opposite the inner surface that receives the stepped surface of the first and second ends that is substantially planar and extends over substantially the entire at least one of first and second ends between the two electrode plates wherein the substantially planar outer surface extends parallel to the planar surfaces of the at least one of the first and second electrode plates,
• wherein the at least one planarizing member extends beyond the first and second steps formed by the outer end of the separator and one of the first or and second electrodes plates, and wherein the planarizing member consists of an insulating resin-based material that is coated and cured on the first end of the electrode assembly.