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.

Sophisticated efficient electrocatalysts are essential to rectifying the shuttle effect and realizing the high performance of flexible lithium-sulfur batteries (LSBs). Phase transformation of MoSe 2 from the 2H phase to the 1T phase has been proven to be a significant method to improve the catalytic activity. However, precisely controllable phase engineering of MoSe 2 has rarely been reported. Herein, by in situ Li ions intercalation in MoSe 2 , a precisely controllable phase evolution from 2H-MoSe 2 to 1T-MoSe 2 was realized. More importantly, the definite functional relationship between cut-off voltage and phase structure was first identified for phase engineering through in situ observation and modulation methods. The sulfur host (CNFs/1T-MoSe 2 ) presents high charge density, strong polysulfides adsorption, and catalytic kinetics. Moreover, Li-S cells based on it display capacity retention of 875.3 mAh g −1 after 500 cycles at 1 C and an areal capacity of 8.71 mAh cm −2 even at a high sulfur loading of 8.47 mg cm −2 . Furthermore, the flexible pouch cell exhibiting decent performance will endow a promising potential in the wearable energy storage field. This study proposes an effective strategy to precisely control the phase structure of MoSe 2 , which may provide the reference to fabricate the highly efficient electrocatalysts for LSBs and other energy systems.