This invention relates to non-aqueous electrolytes, in particular, a non-aqueous electrolyte for lithium-ion secondary batteries. The electrolyte comprises regular organic solvents and electrolyte saline. The special characteristics are: the electrolyte also comprises mixed additives, said mixed additives comprising at least one of those of compound group A, at least one of those of compound group B, and one of those of compound group C wherein: compound group A are selected from inorganic saline including Li.sub.2CO.sub.3, Li.sub.2SO.sub.4, Li.sub.2SO.sub.3, LiNO.sub.3; compound group B are selected from vinylene carbonate, propylene carbonate; and compound group C are selected from ES, PS, DMS, DES, DMSO. The weight ratio can be A:B:C=0.1%-3.0%:0.5%-4.0%:1.0%-5.0%.