Efficient Polysulfides Adsorption and Catalytic Conversion on Germanium Dioxide for High‐Performance Lithium‐Sulfur Batteries

The practical application of lithium‐sulfur (Li‐S) batteries has been hindered by intrinsic limitations, including the sluggish sulfur redox kinetics and the notorious polysulfide shuttle effect. To address these issues, germanium dioxide (GeO 2 ) as a cathode additive is selected, and the fundamental mechanism for performance improvement in Li‐S batteries is systematically investigated. The spherical GeO 2 @S/C composite efficiently enables high sulfur loading via abundant active sites and provides enough space to relieve the volumetric expansion of sulfur during cycling. More importantly, a range of experimental results and theoretical calculations reveal that GeO 2 could enhance electron transfer and optimize the lithium sulfide (Li 2 S) deposition rate, thus accelerating lithium polysulfides (LiPSs) conversion kinetics and suppressing the shuttle effect. Electrochemical tests demonstrate that the 5% GeO 2 @S/C cathode achieves the optimal electrochemical performance when the doping ratio of GeO 2 is set at 5 wt%. Specifically, the 5% GeO 2 @S/C cathode delivers high initial capacity (1116.2 mAh g −1 at 0.2 C), superior rate capability (1046.0 mAh g −1 at 2 C), and excellent long‐term cycling stability with a capacity retention of 68.6% at 1 C after 500 cycles.