LAUSR

Abstract Lithium polysulfides shuttling and limited conductive pathways of the host matrix impose limits on the level of sulfur utilization and long cycle life performance of lithium sulfur batteries. However, precisely designed core shell structures of conductive elements can offer a viable solution. Herein, a facile and scalable approach is presented to synthesize polyaniline (PANi) wrapped ketjenblack carbon-sulfur composites as cathode active materials of the lithium-sulfur battery. PANi synthesized in formic acid displays higher electrical conductivity than that in hydrochloric acid as well as greater doping degree. Formic acid PANi doping avoids any chloride ions that promote pitting corrosion of Al current collectors enabling direct casting of active material slurries. The as-prepared cathode material delivers discharge capacities of 1435 mA h g-1, 850 mA h g-1 and 485 mA h g-1 at C/20, C/5 and 1C with nominal capacity fading for 500 cycles of galvanostatic charge-discharge.