Breaking the Limitations of Sulfur Redox Kinetics by Accelerated Li+-Desolvation in Lithium–Sulfur Batteries
摘要
The practical deployment of lithium–sulfur batteries (LSBs) is fundamentally limited by the sluggish stepwise sulfur redox kinetics. However, current design philosophies remain heavily constrained by the conventional “adsorption-catalysis” strategy, often overlooking the crucial rate-limiting kinetic obstacle of the high Li+ desolvation energy barrier. This sluggish Li+ desolvation process imposes a severe kinetic penalty on polysulfide conversion, thereby depressing electrochemical stability. Herein, we propose a catalyst desolvation strategy utilizing a Ce single-atom catalyst to promote the Li+ desolvation process, thereby enhancing the redox conversion of polysulfides. Results indicate that the catalyst desolvation strategy increases the proportion of contact ion pairs and aggregates, reduces the Li+ desolvation energy barrier, and stabilizes the lithium anode/electrolyte interface. Consequently, the accelerated Li+ desolvation facilitates rapid sulfur redox kinetics, thereby realizing stable cycling in LSBs with a low decay rate of 0.036% per cycle over 1700 cycles at 1 C. This work confirms the significant impact of Li+ desolvation and provides a new solution for achieving efficient conversion of polysulfides in LSBs.