ELECTRODE STRUCTURE AND LITHIUM SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To further suppress the increase in internal resistance of a lithium secondary battery.SOLUTION: A lithium secondary battery of the present invention comprises: a positive electrode sheet 15 including a collector 13C and a positive electrode mixture layer 14 formed on the collector; a negative electrode sheet 18 including a collector 16C and a negative electrode mixture layer 17 formed on a surface of the collector; a separator 26 provided between the positive electrode sheet 15 and the negative electrode sheet 18; and a nonaqueous electrolyte 20 filled in between the positive electrode sheet 15 and the negative electrode sheet 18. In the lithium secondary battery, the negative electrode sheet 18 enwrapped by the separator 26, and the positive electrode sheet 15 is put on the negative electrode sheet thus enwrapped; in this state, the positive and negative electrode sheets and separator are wound and encased in a cylindrical case 21. The negative electrode sheet 18 has a structure arranged so that the separator 26 includes a negative electrode active material, and the separator 26 is sealed to make more difficult for the nonaqueous electrolyte 20 to escape.