Electrolyte for non-aqueous batteries and secondary battery using the same

The non-aqueous electrolyte-containing secondary battery of the present invention uses a non-aqueous electrolyte including at least one phosphoric ester derivative expressed by Formula (1): (RO)(RO)P(O)X and by Formula (2): R(O)P(O)X2, wherein R, R, and R independently denote aliphatic hydrocarbon groups having 1 to 12 carbon atoms and X denotes a halogen atom. This arrangement improves the high-temperature storage characteristics after charging and the charge-discharge cycle characteristics of the secondary battery.