To provide a nonaqueous electrolyte composition capable of preventing bulging deformation of an outer packaging of a battery in the storage at high temperatures, and to provide a nonaqueous electrolyte secondary battery using the nonaqueous electrolyte composition.

The nonaqueous electrolyte composition is prepared in such a way that an electrolyte salt, a chain carbonate having at least a 13-20C hydrocarbon group or halogenated hydrocarbon group, a cyclic sulfonate and/or sulfone having multiple bond, and if necessary, other carbonate having double bond between carbons or a polymer compound are contained in a nonaqueous solvent, and the nonaqueous electrolyte secondary battery is manufactured by using the nonaqueous electrolyte composite.

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