The invention relates to the field of electrochemistry, in particular to a lithium ion battery. The invention provides a lithium ion battery, comprising a positive pole piece, a negative pole piece, a separator and an electrolyte, the positive pole piece comprises a positive current collector and a positive active material layer, and the positive active material layer comprises a positive active material and Positive electrode additive, the positive electrode additive is selected from lithium phosphate compounds, the electrolyte includes electrolyte and solvent, the electrolyte also includes acid scavenger and film-forming additive, and the acid scavenger is selected from cyclic acid anhydride compounds , the film-forming additive is selected from boroxine compounds. The inventors of the present invention can stabilize the lithium salt by introducing positive electrode additives into the positive electrode sheet, and further introduce acid scavenger and film-forming additives into the electrolyte of the battery, thereby avoiding the decomposition of lithium salts to generate HF and accelerating the dissolution of positive manganese , and can remove HF in the electrolyte, effectively improving the cycle performance and / or storage performance of the battery.