Highly efficient and stable cryo-ground sulphur cathode for Li-S batteries

Abstract

Here we report on a Li-S battery with cathode, based on a S powder obtained from bulk amorphous S, by cryogenic grinding. The cathode was prepared from a slurry, wherein the content of cryo-ground S powder was equal to 80 wt % (corresponds to approximate to 2.26 mg cm(-2)). Other slurry components included carbon Super P, and polyvinylidene fluoride, dispersed in N-methylpyrrolidone. The electrochemical performance of the as-prepared battery was compared to a battery based on an identically prepared paste, but containing reference S powder (with the orthorhombic structure). A longer life cycle, and enhanced capacity per gram, as well as per cm(2) of electrode was revealed for the cryo-ground S-based cathode. The electrochemical results show that the loss in capacity of the cryo-ground S powder cathode was just 3% after 50 cycles, which suggests on a higher stability of S inside the cathode during cycling.