NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

The invention intends to provide a high-capacity type non-aqueous electrolyte secondary battery that includes a nickel-containing lithium composite oxide as a positive electrode active material and exhibits good charge/discharge cycle characteristics even under a high temperature environment. The invention is a non-aqueous electrolyte secondary battery including: a positive electrode including a nickel-containing lithium composite oxide as a positive electrode active material; a negative electrode capable of absorbing and desorbing lithium; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte including a non-aqueous solvent and a solute dissolved in the non-aqueous solvent. In the nickel-containing lithium composite compound after a discharge to a predetermined cut-off voltage of discharge, the molar ratio r of lithium to the other metal elements than lithium is 0.85 or more and 0.92 or less. The non-aqueous electrolyte includes a fluorine-containing sulfonate compound.