The present disclosure relates to a lithium ion battery. The lithium ion battery cathode includes a cathode, a separator, an anode, and a nonaqueous electrolyte solution. The cathode includes a cathode current collector and a cathode material layer disposed on a surface of the cathode current collector. The cathode material layer comprises cathode active material, conductive agent, and adhesive uniformly mixed together. The cathode active material comprises cathode active material particles and AlPO4 layers coated on surfaces of the cathode active material particles. The separator includes a porous membrane and a protective layer coated on a surface of the porous membrane. The protective layer prevents the separator from being melted during charging or discharging of the lithium ion battery.