Patent ID: 8247116

Claim:
A method for making an electrode, the method comprising the steps of: providing a modifier and a current collector; applying an electrode material layer on a top surface of the current collector; coating the modifier on a top surface of the electrode material layer to form a coating layer, and heat treating the coated current collector to transform the coating layer to a protective film; wherein the modifier is a clear solution formed by the following steps: providing a solution of a phosphorous source having a phosphate radical; mixing the solution of the phosphorous source having the phosphate radical with a liquid solvent to form a first solution; putting a trivalent aluminum source into the first solution to form a suspension; and adding a metallic oxide to the suspension to react with the suspension to form the clear solution; wherein a molar ratio of the trivalent aluminum source, the metallic oxide, and the phosphorous source is set by (Mol Al +Mol Metal ):Mol p =about 1:2.5 to about 1:4, Mol Al is the amount of substance of the aluminum element in the trivalent aluminum source, Mol Metal is the amount of substance of the metallic element in the metallic oxide, and Mol p is the amount of substance of the phosphorous element in the phosphorous source.