LITHIUM SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a lithium secondary battery improving a charging/discharging cycle life property from 67% up to 86% at a 300-time evaluation.

SOLUTION: The lithium secondary battery 1 includes a positive electrode 2 containing a positive electrode active substance capable of reversibly inserting and separating lithium ions; a negative electrode 3 containing a negative electrode active substance; and an electrolyte solution. An arithmetic average value Ra of the surface roughness of the positive electrode 2 or an arithmetic average value Ra of the surface roughness of the negative electrode 3 after conducting a charge-discharge process with the battery 1 are 155 to 419 nm and 183 to 1,159 nm, respectively. The cycle life property is improved from 67% up to 86% at a 300-time evaluation by reducing the surface roughness of an electrode plate.

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