NONAQUEOUS-ELECTROLYTE SECONDARY BATTERY AND MANUFACTURING METHOD THEREFOR

摘要

This nonaqueous-electrolyte secondary battery has the following: a positive electrode; a negative electrode containing an active material that contains a titanium oxide that has a lithium-ion absorption potential of at least 1.2 V (relative to Li/Li+); an electrolyte containing lithium salts including lithium hexafluorophosphate and lithium tetrafluoroborate; and a nonaqueous solvent containing ethylene carbonate, a cyclic carboxylic-acid ester or a C4+ cyclic carbonate, and a chain carbonate. Ethylene carbonate constitutes between 5% and 20% of the total volume of the nonaqueous solvent, inclusive, and the concentration of lithium tetrafluoroborate with respect to the nonaqueous liquid electrolyte is between 0.05 and 0.5 mol/L, inclusive.