NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

The main purpose of the present invention is to provide a high-capacity, nonaqueous electrolyte secondary battery that has no precipitation of metal such as lithium and that has excellent cycle characteristics. In this nonaqueous electrolyte secondary battery, a wound electrode group (30) comprises a positive electrode (10) having a positive electrode active substance layer formed on both surfaces of a belt-form positive electrode current collector body, and a negative electrode (20) having a negative electrode active substance layer formed on both surfaces of a belt-form negative electrode current collector body. The charge capacity of the negative electrode (20) when the nonaqueous electrolyte secondary battery is at full charge is set to within the range of 83-99% of the theoretical capacity of said negative electrode (20), and, if R1 is the diameter of the innermost side of the electrode group (30) and t is the thickness of the negative electrode, then the mass M1 of the active substance per unit surface of a negative electrode active substance layer (22a) formed on the outer circumference side of the negative electrode current collector body, and the mass M2 of the active substance per unit surface of a negative electrode active substance layer (22b) formed on the inner circumference side fulfill the relation M1/M2 < (R1+r/2)/(R1-t/2).