NONAQUEOUS ELECTROLYTE AND NONAQUEOUS-ELECTROLYTE SECONDARY BATTERY

A nonaqueous electrolyte which contains an ionic liquid having general formula (1) below and a melting point not higher than 50 DEG C, a compound which reductively decomposes at a more noble potential than the ionic liquid, and a lithium salt. In formula (1), R to R are each independently an alkyl group of 1 to 5 carbons or an alkoxyalkyl group of the formula R'-O-(CH2)n- (R' being methyl or ethyl, and the letter n being an integer from 1 to 4), and any two from among R, R, R and R may together form a ring, with the proviso that at least one of R to R is an alkoxyalkyl group of the above formula. X is a nitrogen atom or a phosphorus atom, and Y is a monovalent anion.