Dynamic Li ⁺ Respiration Effect Enables Cascade Conversion of Lithium Polysulfides for Li–S Batteries

Abstract

Abstract High‐energy‐density lithium–sulfur batteries exhibit obvious kinetics differences involving multistep reactions, making it hard to realize constantly high‐efficient polysulfide conversion during the full charging/discharging Herein, we propose a concept of Li + ‐respiration‐effect‐induced cascade catalysis through taking full advantage of dynamic active sites from in situ potential‐modulated TiNb 2 O 7 . The Li + respiration effect activates the lattice O atom and regulates the antibonding orbitals filling, triggering an electrochemical‐dominated switchable catalytic for sequential conversion of intermediates. As a result, the Li–S cell displays a good cycling stability and wide‐temperature ability from −30 to +60 °C. A flexible pouch cell maintains a capacity retention of 94.6% after 120 cycles. Our discovery provides a fire‐new perspective in electrochemically reconstructed catalysis for wide‐temperature‐tolerant Li − S batteries.