Carbon Interlayers: A Universal and Effective Approach for Suppress the Shuttle Effect for Lithium-Sulfur Batteries

Abstract

Due to the advantages of high theoretical capacity, high security, and low cost, lithium-sulfur batteries (LSBs) have been recognized as one of the research hotspots of the next generation energy storage technology in contemporary years. However, the inevitable lithium polysulfide intermediates dissolution and migration severely hamper its energy density and calendar life. To overcome the shuttle effect in lithium sulfur batteries, the design of a carbon interlayer between the separator and the cathode is a promising technique. Herein, activated carbon (AC) and acetylene black (AB) respectively as carbon interlayer of LSBs between the separator and the cathode was reported. Therein, AC possesses a rich pore structure that enables rapid physical adsorption of lithium polysulfide (LiPS). And AB has better conductivity and provides higher capacity. Thus, Li-S cells using AC carbon interlayer exhibited favorable cycling stability over long-term cycling, with a decay rate of 0.097% per cycle of 0.2 C for 500 cycles. As a contrast, the cells employing the AB carbon interlayer displayed a high initial capacity of 2048 mAh g-1.

Keywords: lithium-sulfur batteries, activated carbon, acetylene black, polysulfide