ELECTROLYTE FOR LITHIUM SECONDARY BATTERY OF IMPROVED LOW-TEMPERATURE PROPERTY AND SECONDARY BATTERY CONTAINING THE SAME

摘要

A lithium nonaqueous electrolyte, and a lithium secondary battery containing the electrolyte, a lithium manganese-based metal oxide as a positive electrode active material and a graphite-free carbon material as a negative electrode active material are provided to improve the low temperature characteristics of a battery by improving the reactivity of a lithium ion and an electrode. A lithium nonaqueous electrolyte comprises 0.1-20 wt% of an inorganic salt represented by R4 X^+ Y Z_n^-, wherein R is a C3-C10 alkyl group; X is N or P; Y is B or P; Z is a C3-C10 alkyl group, a C4-C10 cyclic or aromatic group or a halogen atom; and n is 4 or 6 and is determined by the oxidation number of Y according to the kind of X and Y. Preferably the inorganic salt is a lithium manganese oxide, lithium manganese composite oxide, or LiMn2O4 whose some Li is substituted with an alkaline earth metal ion.