Construction of 1T-MoSe₂ /TiC@C Branch-Core Arrays as Advanced Anodes for Enhanced Sodium Ion Storage

The use of active sites and reaction kinetics of MoSe₂ anodes for sodium ion batteries (SIBs) are highly related to the phase components (1T and 2H phases) and electrode architecture. This study concerns the design and fabrication of wrinkled 1T-MoSe₂ nanoflakes anchored on highly conductive TiC@C nanorods to form 1T-MoSe₂ /TiC@C branch-core arrays by a powerful chemical vapor deposition (CVD)-solvothermal method. The 1T-MoSe₂ branch can be easily transformed into its 2H-MoSe₂ counterpart after a facile annealing process. In comparison to 2H-MoSe₂ , 1T-MoSe₂ has larger interlayer spacing and higher electronic conductivity, which are beneficial for the acceleration of reaction kinetics and capacity improvement. In addition, direct growth of 1T-MoSe₂ nanoflakes on the TiC@C skeleton not only enhance the electrical conductivity, but also contribute to reinforced structural stability. Accordingly, 1T-MoSe₂ /TiC@C branch-core arrays are demonstrated with higher capacity and better rate performance (184 mAh g^-1 at 10 A g^-1 ) and impressive durability over 500 cycles with a capacity retention of approximately 91.8 %. This phase modulation plus branch-core design provides a general method for the synthesis of other high-performance electrode materials for application in electrochemical energy storage.