LAUSR

Phase transition engineering, with the ability to alter the electronic structure and physicochemical properties of materials, has been widely used to achieve the thermodynamically unstable metallic phase MoS2 (1T-MoS2), although the complex operating conditions and low yield of previous strategies make the large-scale fabrication of 1T-MoS2 a big challenge. Herein, we report a facile electron injection strategy for phase transition engineering and fabricate a composite of conductive TiO chemically bonded to 1T-MoS2 nanoflowers (TiO-1T-MoS2 NFs) on a large scale. The underlying mechanism analysis reveals that electron-injection-engineering triggers a reorganization of the Mo 4d orbitals and results in a 100% phase transition of MoS2 from 2H to 1T. In the TiO-1T-MoS2 NFs composite, the 1T-MoS2 demonstrates a higher electronic conductivity, a lower Na+ diffusion barrier, and a more restricted S release than 2H-MoS2. In addition, conductive TiO bonding successfully resolves the stability challenge of the 1T phase. These merits endow TiO-1T-MoS2 NFs electrodes with an excellent rate capability (650/288 mAh g-1 at 50/20 000 mA g-1, respectively) and an outstanding cyclability (501 mAh g-1 at 1000 mA g-1 after 700 cycles) in sodium ion batteries. Such an improvement signifies that this facile and scalable phase-transition engineering combined with a deep mechanism analysis offers an important reference for designing advanced materials for various applications.