CYLINDRICAL NONAQUEOUS ELECTROLYTIC SECONDARY BATTERY

摘要

A cylindrical non-aqueous electrolyte secondary battery of the invention includes: an approximately columnar electrode group having a strip-shaped positive electrode including a positive electrode material mixture layer formed on a positive electrode current collector and a strip-shaped negative electrode including a negative electrode material mixture layer formed on a negative electrode current collector that are spirally wound with a strip-shaped separator interposed therebetween; a non-aqueous electrolyte; a bottomed cylindrical battery case housing the electrode group and the non-aqueous electrolyte; and a negative electrode lead electrically connecting the negative electrode and the battery case. The negative electrode includes a double-coated portion having a negative electrode material mixture layer formed on both surfaces of the negative electrode current collector, a single-coated portion having a negative electrode material mixture layer formed on one surface of the negative electrode current collector, and an uncoated portion where both surfaces of the negative electrode current collector are exposed. The single-coated and uncoated portions are disposed at an outermost layer of the electrode group. The negative electrode current collector exposed portions of the single-coated and uncoated portions are in direct contact with an inner surface of the battery case.