Lithium secondary battery

A lithium secondary battery provided with a positive electrode capable of intercalating and eliminating lithium ions, a negative electrode capable of intercalating and eliminating lithium ions, and an electrolyte, wherein

• at least one of an imide group lithium salt represented by LiN(CmF2m+1SO2)(CnF2n+1SO2) (wherein m and n each denote an integer of 1 to 4 and may be the same or different from each other) and amethide group lithium salt represented by LiC(CpF2p+1SO2)(CqF2q+1SO2)(CrF2r+1SO2) (wherein p, q, and r each denote an integer of 1 to 4 and may be the same or different from each other) is contained as a component of a solute in said electrolyte, and a phosphorus compound is added to said electrolyte, wherein
• said phosphorus compound added to the electrolyte is at least one phosphorus compound selected from the group consisting of LiPO3 and Li3PO4 and wherein
• said phosphorus compound is added to the electrolyte in the range of 0.001 to 10.0 wt % based on the total weight of the electrolyte.

The lithium secondary battery provided with a positive electrode capable of intercalating and eliminating lithium ions, a negative electrode capable of intercalating and eliminating lithium ions, and an electrolyte, wherein

• at least one of an imide group lithium salt represented by LiN(CmF2m+1SO2)(CnF2n+1SO2) (wherein m and n each denote an integer of 1 to 4 and may be the same or different from each other) and a methide group lithium salt represented by LiC(CpF2p+1SO2)(CqF2q+1SO2)(CrF2r+1SO2) (wherein p, q, and r each denote an integer of 1 to 4 and may be the same or different from each other) is contained as a component in a solute in said electrolyte, and both of a fluoride and a phosphorus compound are added to said electrolyte, wherein
• said fluoride added to the electrolyte is at least one fluoride selected from the group consisting of AgF, CoF2, CoF3, CuF, CuF2, FeF2, FeF3, LiF, MnF2, MnF3, SnF2, SnF4, TiF3, TiF4, and ZrF4.

A lithium secondary battery provided with a positive electrode capable of intercalating and eliminating lithium ions, a negative electrode capable of intercalating and eliminating lithium ions. and an electrolyte, wherein

• at least one of an imide group lithium salt represented by LiN(CmF2m+1SO2)(CnF2n+1SO2) (wherein m and n each denote an integer of 1 to 4 and may be the same or different from each other) and a methide group lithium salt represented by LiC(CpF2p+1SO2)(CqF2q+1SO2)(CrF2r+1SO2) (wherein p, q, and r each denote an integer of 1 to 4 and may be the same or different from each other) is contained as a component of a solute in said electrolyte, and a phosphorus compound consisting of LiPO3 is added to said electrolyte.

A lithium secondary battery provided with a positive electrode capable of intercalating and eliminating lithium ions, a negative electrode capable of intercalating and eliminating lithium ions, and an electrolyte, wherein

• at least one of an imide group lithium salt represented by LiN(CmF2m+1SO2)(CnF2n+1SO2) (wherein m and n each denote an integer of 1 to 4 and may be the same or different from each other) and a methide group lithium salt represented by LiC(CpF2p+1SO2)(CqF2q+1SO2)(CrF2r+1SO2) (wherein p, q, and r each denote an integer of 1 to 4 and may be the same or different from each other) is contained as a component in a solute in said electrolyte, and both of a fluoride and at least one phosphorus compound selected from the group consisting of LiPO3, and Li3PO4 are added to said electrolyte, wherein
• a total amount of said fluoride and phosphorus compound added to the electrolyte is in the range of 0.001 to 10.0 wt % based on the total weight of the electrolyte.