Acceleration of Cathode Interfacial Kinetics by Liquid Organosulfides in Lithium Metal Batteries.

Abstract

Great efforts have been made to tackle the issues of the shuttle effect and kinetics hysteresis in lithium-sulfur (Li-S) battery, but few on tuning the reaction path of sulfur cathode. Herein, we report a strategy to replace inorganic sulfur with liquid organosulfide and construct a novel liquid-liquid interface between cathode and electrolyte, which effectively inhibits the shuttle effect and simplifies the solid-liquid-solid conversion reaction to only liquid-solid process, thus greatly improving the reaction kinetics. The Li|PTS half-cell exhibits excellent cycling stability at 0.5 C, with a capacity retention of 64.9 % after 750 cycles. The Li|PTS pouch cell with a high PTS loading of 3.1 g delivers a maximum capacity of 997 mAh and maintains 82.1 % of initial capacity after 50 cycles at the current of 100 mA. This work enriches the reaction mechanism of Li-S batteries and provides new insights for the development of interphase chemistry in the design of cathodes.