In Situ Electrochemical Intercalation-Induced Phase Transition to Enhance Catalytic Performance for Lithium-Sulfur Battery

Accelerating the conversion of polysulfide to inhibit shutting effect is a promising approach to improve the performance of lithium-sulfur batteries. Herein, the hollow titanium nitride (TiN)/1T-MoS2 heterostructure nanospheres are designed with efficient electrocatalysis properties serving as a sulfur host, which is formed by in situ electrochemical intercalation from TiN/2H-MoS2. Metallic, few-layered 1T-MoS2 nanosheets with abundant active sites decorated on TiN nanospheres enable fast electron transfer, high adsorption ability toward polysulfides, and favorable catalytic activity contributing to the conversion kinetics of polysulfides. Benefiting from the synergistic effects of these favorable features, the as-developed hollow TiN/1T-MoS2 nanospheres with advanced architecture design can achieve a high discharge capacity of 1273 mAh g(-1) at 0.1 C, good rate performance with a capacity retention of 689 mAh g(-1) at 2 C, and long cycling stability with a low-capacity fading rate of 0.051% per cycle at 1 C for 800 cycles. Notably, the TiN/1T-MoS2/S cathode with a high sulfur loading of up to 7 mg cm(-2) can also deliver a high capacity of 875 mAh g(-1) for 50 cycles at 0.1 C. This work promotes the prospect application for TiN/1T-MoS2 in lithium-sulfur batteries.

Automated summary

The hollow TiN/1T-MoS2 nanospheres designed in this study demonstrate efficient conversion of polysulfides to enhance the performance of lithium-sulfur batteries, achieving high discharge capacity, good rate performance, and long cycling stability.