MXene‐Induced 2D Hard Carbon with In Situ Embedding of TiC Scaffolds Enabling Fast Na+ Diffusion and Interfacial Stabilization

Abstract In situHard carbon (HC) is considered to be the most promising anode material for sodium‐ion batteries (SIBs) due to the structural diversity, and low cost. However, limited Na + transfer kinetics and structural defects lead to low initial Coulombic efficiency (ICE) and poor rate performance (typically <5 A g −1 ) of HC anodes. In this work, an interesting morphology‐induced strategy is reported to synthesize 2D HC material. MXene is introduced into sugar‐derived HC during hydrothermal process. After the subsequent carbonization, the as‐obtained composite (TC5‐1300) inherits the lamellar structure of MXene, and TiC nanoparticles by Ti 3 C 2 MXene reacting with carbon are embedded into carbon layer. This concentrated architecture not only provides a robust scaffold for sodium storage, but also greatly reduces the defects of HC. Therefore, TC5‐1300 maintains a high reversible capacity of 267.28 mA h g −1 after 500 cycles at 2 A g −1 with a high ICE of 86.27%. Attributed to the excellent Na + diffusion ability and interfacial stabilization, TC5‐1300 exhibit a reversible capacity of 194 mA h g −1 even at 8 A g −1 . Furthermore, this morphology tailoring strategy can be generalized to other sugar sources derived carbon materials, which provides a valuable solution to commercial development of HC anodes.