Positive electrode material for lithium ion battery, method for preparing the same and lithium ion battery
The present invention provides a positive electrode material for a lithium ion battery including a nickel-containing positive electrode material and a coating layer coated on the nickel-containing positive electrode material, wherein the nickel-containing positive electrode material has a chemical formula of LiNi x M 1-x O 2 , 0.5≤x≤1, M is at least one of Co, Mn and Al, and the coating layer contains lithium vanadium phosphate and silica. Compared with the prior art, the coating layer containing lithium vanadium phosphate and silica coated on the nickel-containing positive electrode material of the present invention can remarkably improve the dynamic performances and the cycle performances at high voltage of the lithium ion battery. In addition, the present invention also provides a method for preparing the positive electrode material a lithium ion battery containing the positive electrode material.
1. A positive electrode material for a lithium ion battery, comprising a nickel-containing positive electrode material and a coating layer coated on the nickel-containing positive electrode material, wherein the nickel-containing positive electrode material has a chemical formula of LiNi x M 1-x O 2 , 0.5≤x≤1, M is at least one of Co, Mn and Al, and the coating layer contains lithium vanadium phosphate and silica, wherein a weight ratio of the lithium vanadium phosphate to the nickel-containing positive electrode material is 0.2% to 1% and a weight ratio of the silica to the nickel-containing positive electrode material is 0.05% to 0.2%.
2. The positive electrode material for a lithium ion battery according to claim 1 , wherein the silica has a particle diameter of 15 nm to 60 nm.
3. The positive electrode material for a lithium ion battery according to claim 1 , wherein the coating layer containing lithium vanadium phosphate and silica has a thickness of 60 nm to 200 nm.
4. A lithium ion battery, comprising a positive electrode plate, a negative electrode plate, a separator interposed between the positive electrode plate and the negative electrode plate, and electrolyte, the positive electrode plate comprises a positive electrode current collector and a positive electrode material on the positive electrode current collector, the negative electrode plate comprises a negative electrode current collector and a negative electrode material on the negative electrode current collector, wherein the positive electrode material comprise a nickel-containing positive electrode material and a coating layer coated on the nickel-containing positive electrode material, the nickel-containing positive electrode material has a chemical formula of LiNi x M 1-x O 2 , 0.5≤x≤1, M is at least one of Co, Mn and Al, and the coating layer contains lithium vanadium phosphate and silica, wherein a weight ratio of the lithium vanadium phosphate to the nickel-containing positive electrode material is 0.2% to 1% and a weight ratio of the silica to the nickel-containing positive electrode material is 0.05% to 0.2%.
5. The lithium ion battery according to claim 4 , wherein the silica has a particle diameter of 15 nm to 60 nm.
6. The lithium ion battery according to claim 4 , wherein the coating layer containing lithium vanadium phosphate and silica has a thickness of 60 nm to 200 nm.