RECHARGEABLE LITHIUM BATTERY

摘要

Provided is a lithium secondary battery whose cycle lifetime characteristic is improved from 67 % to 86 % in the case of the test of 300 cycles. The lithium secondary battery comprises a positive electrode which comprises a positive electrode active material capable of reversibly intercalating or deintercalating a lithium ion; a negative electrode which comprises a negative electrode active material; and an electrolyte solution, wherein the positive electrode has a surface roughness arithmetic average Ra of 155-410 nm after charge/discharge process and/or the negative electrode has a surface roughness arithmetic average Ra of 183-1,159 nm after charge/discharge process. Preferably the positive electrode has a surface roughness average square root Rq of 219-591 nm and/or the negative electrode has a surface roughness average square root Rq of 238-1,518 nm after charge/discharge process.