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

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 Ti₃C₂ 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.