A modifier of a lithium ion battery includes a clear solution fabricated from a phosphorous source having a phosphate radical, a trivalent aluminum source, and a metallic oxide provided in a liquid phase solvent. A molar ratio of the trivalent aluminum source, the metallic oxide, and the phosphorous source is set by (MolAl+MolMetal):Molp=about 1:2.5 to about 1:4. MolAl is the amount of substance of an aluminum element in the trivalent aluminum source, MolMetal is the amount of substance of a metallic element in the metallic oxide, and Molp is the amount of substance of a phosphorous element in the phosphorous source.