Syntheses and Application of All-lithium Salts of Heteropolyacid as Electrolyte of Lithium-ion Battery

The all-lithium salts of heteropoly acid LixXM 12O 40（HPA-Li）（X=P, Si; M=Mo, W） were obtained via ion exchange and characterized by means of IR and UV spectroscopies, TG and elemental analyses. The conductivity of the electrolytic solution consisting of Li3PW 12O 40 and PC/DME mixing solvent（1/2.5, volume ratio） is up to 7.2×10 -2 S/cm, being higher than that of LiClO4 as the electrolyte. The all-lithium salts were used as electrolytes in secondary lithium-ion batteries. The discharge capacity of the PAS/Li batteries with Li3PW 12O 40 electrolyte solutions reaches to 148 （mA·h）/g and the cyclic life is up to 380 times, much better than those of commercialized products with LiClO4 and LiAsF6 as electrolytes.