Phase Reconstruction‐Assisted Electron‐Li+ Reservoirs Enable High‐Performance Li‐S Battery Operation Across Wide Temperature Range

Abstract

AbstractLithium‐sulfur batteries (LSBs) are known as high energy density, but their performance deteriorates sharply under high/low‐temperature surroundings, due to the sluggish kinetics of sulfur redox conversion and Li+ transport. Herein, a catalytic strategy of phase reconstruction with abundant “electron‐Li+” reservoirs has been proposed to simultaneously regulate electron and Li+ exchange. As a demo, the 1T‐phase lithiation molybdenum disulfide grown on hollow carbon nitride (1T‐LixMoS2/HC3N4) is achieved via in situ electrochemical modulation, where the 1T‐LixMoS2 serves as an auxiliary “Li+ source” for facilitating Li+ transport and the HC3N4 acts as an electron donor for electronic supplier. From the theoretical calculations, experimental and post‐modern analyses, the relationship between the catalytic behaviors and mechanism of “electron‐Li+” reservoirs in accelerating the rate‐determining kinetics of sulfur species are deeply understood. Consequently, the cells with 1T‐LixMoS2/HC3N4/PP functional separator demonstrate excellent long‐term electrochemical performance and stabilize the areal capacity of 6 mAh cm−2 under 5.0 mg cm−2. Even exposed to robust surroundings from high (60 °C) to low (0 °C) temperatures, the optimized cells exhibit high‐capacity retention of 76.2% and 90.4% after 100 cycles, respectively, pointing out the potential application of catalysts with phase reconstruction‐assisted “electron‐Li+” reservoirs in LSBs.