A metallically conductive TiB 2 is developed to construct multifunctional separator toward improved lithium-sulfur (Li–S) battery performance. Coupled with two-dimensional graphene, the obtained TiB 2 @G separator fulfills a synergistic combination of strong physical and chemical sulfur immobilization as well as a high-efficiency sulfur reutilization, thus establishing a robust barrier against the polysulfide shuttling and enabling a fast and durable sulfur electrochemistry . As a result, cells based on TiB 2 @G separator exhibit a high sulfur utilization with 1350 mA h g −1 capacity at 0.05C, superb rate capability up to 5.0C, and excellent cyclability with a high capacity retention over 85% after 300 cycles at 0.5C. Moreover, significantly mitigated self-discharge and considerably high areal capacity of 5.8 mA h cm −2 can be also achieved, indicating the great promise of this separator design for the development of high-performance Li–S batteries.
The adsorption-catalysis synergy for accelerated conversion of polysulfides is critical toward the electrochemical stability of lithium-sulfur battery (LSB). Herein, a non-metallic polymer network with anion receptor units, trifluoromethanesulfonyl (CF 3 SO 2 -) substituted aza-ether, was in-situ integrated on PE separator, working as an efficient host for anchoring lithium thiophosphates (LPS) as redox mediators and polysulfides through Lewis acid-base interaction. The anchored LPS on the modified PE separator displayed a robust chemical adsorption ability towards polysulfides through the formation of S S bond. Meanwhile, LPS decreased the energy barrier of Li 2 S nucleation and promoted redox reaction kinetics. The battery with LPS decorated separator revealed a long cycling lifespan with a per cycle decay of 0.056 % after 600 cycles, and a competitive initial capacity of 889.1 mAh/g when the of sulfur cathode increased to 3 mg cm −2 . This work developed a new design strategy to promote the utilization of lithium phosphorus sulfide compounds in LSB.
危险品化学品经营许可证（带存储）