| abstract |
The present invention provides a lithium ion battery, which includes a positive pole piece, a negative pole piece, a separator and a non-aqueous electrolyte. The positive pole piece includes Li 1+x Ni a Co b Me (1‑a‑b) O 2‑c Y c , ‑0.1≤x≤0.2, 0.8≤a<1, 0<b<1, 0<(1‑a‑b)<1,0≤c<1, Me is selected from one or more of Mn, Al, Mg, Zn, Ga, Ba, Fe, Cr, Sn, V, Sc, Ti, Zr species, and Y is selected from one or more of F, Cl, and Br. The non-aqueous electrolyte includes a non-aqueous solvent and a lithium salt, the non-aqueous solvent includes a carbonate-based solvent and a high oxidation potential type solvent, and the high oxidation potential type solvent is selected from the compounds shown in formula I and formula II one or more of them. The invention can not only improve the electrochemical performance of the lithium ion battery under high temperature and high voltage, and improve the safety performance of the lithium ion battery such as overcharge safety, hot box safety, etc., while ensuring that the lithium ion battery has high energy density, but also Ion batteries have certain kinetic properties. |