Harnessing Plasma‐Assisted Doping Engineering to Stabilize Metallic Phase MoSe<sub>2</sub> for Fast and Durable Sodium‐Ion Storage
Hanna He, Zhang Hehe, Dan Huang, Wei Kuang, Xiaolong Li, Junnan Hao, Zaiping Guo, Chuhong Zhang
Abstract
Abstract Metallic‐phase selenide molybdenum (1T‐MoSe 2 ) has become a rising star for sodium storage in comparison with its semiconductor phase (2H‐MoSe 2 ) owing to the intrinsic metallic electronic conductivity and unimpeded Na + diffusion structure. However, the thermodynamically unstable nature of 1T phase renders it an unprecedented challenge to realize its phase control and stabilization. Herein, a plasma‐assisted P‐doping‐triggered phase‐transition engineering is proposed to synthesize stabilized P‐doped 1T phase MoSe 2 nanoflower composites (P‐1T‐MoSe 2 NFs). Mechanism analysis reveals significantly decreased phase‐transition energy barriers of the plasma‐induced Se‐vacancy‐rich MoSe 2 from 2H to 1T owing to its low crystallinity and reduced structure stability. The vacancy‐rich structure promotes highly concentrated P doping, which manipulates the electronic structure of the MoSe 2 and urges its phase transition, acquiring a high transition efficiency of 91% accompanied with ultrahigh phase stability. As a result, the P‐1T‐MoSe 2 NFs deliver an exceptional high reversible capacity of 510.8 mAh g −1 at 50 mA g −1 with no capacity fading over 1000 cycles at 5000 mA g −1 for sodium storage. The underlying mechanism of this phase‐transition engineering verified by profound analysis provides informative guide for designing advanced materials for next‐generation energy‐storage systems.