PURPOSE: To provide a nonaqueous electrolyte secondary battery of high energy density.

CONSTITUTION: For a nonaqueous electrolyte secondary battery which consists of a charge and discharge allowable positive electrode 1, nonaqueous electrolyte and a charge and discharge allowable negative electrode 4, a C5N electrode is used as the positive electrode 1. By using the C5N positive electrode, the nonaqueous electrolyte secondary battery is excellent in high voltage, high capacity and reservation property.