High-voltage lithium ion battery

The invention discloses a high-voltage lithium ion battery, which comprises a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode slurry material coating the surface of the positive electrode current collector; the positive electrode slurry material comprises a positive electrode active substance, a conducting agent A and a bonding agent A; the negative electrode plate comprises a negative electrode current collector and a negative electrode slurry material coating the surface of the negative electrode current collector; the negative electrode slurry material is prepared from a negative electrode active substance, a conducting agent B, a dispersing agent and a bonding agent B; the electrolyte is prepared from lithium salt, non-aqueous organic solvents and additives of lithium difluorophosphate. The LiDFP is used as an electrolyte additive; the HOMO energy stage is higher than that of the electrolyte solvent molecules; the oxidization reaction can preferentially occur on the surface of the positive electrode; the stable SEI film is formed; the decomposition reaction of the electrolyte is inhibited; the loss of the nonreversible energy is reduced; the normal temperature circulation performance of the high-voltage lithium ion battery can be obviously improved.