High energy density Li-S and Li-air batteries
In addition to cutting-edge research in Si anodes for advanced Li-ion batteries, our group has also explored future batteries. The challenges facing the commercialization of Li-S batteries are poor cycling stability and low coulombic efficiency, which are induced by the dissolution of polysulfides into the electrolyte, and the shuttle reaction. The current technique is to physically restrain the polysulfide dissolution by using barrier materials; however, this only lessens these challenges. Our group solved this problem by breaking S8 into S4 and S2 at temperatures above 500oC and bonding them onto carbon so that soluble high order polysulfides could not be formed. The DCNTs, impregnated with sulfur at temperatures of 500oC, demonstrated great cycling stability and 96% coulombic efficiency.