The present application relates to the technical field of secondary batteries and, specifically, relates to an electrolyte and lithium-related secondary batteries containing the electrolyte. The electrolyte of the present application comprises a lithium salt, organic solvent A and organic solvent B. The solvent A is hydrofluorocarbon (HFC) compounds and the chemical formula is CxHyFz, where x is from 4 to 10, Z:Y ratio is from 2:1 to 10:1. The solvent B is the common component used in state-of-art electrolyte in lithium-related battery technologies, like carbonates, esters or ethers. The molar ratio of the solvent A in the electrolyte ranges from 8 mol% to 80 mol%. The battery of the present application has high flash point, non-flammable and high capacity retention rate.