Spatially confined synthesis of TiNb2O7quantum dots onto mesoporous carbon and Ti3C2TXMXene for boosting lithium storage

TiNb2O7has been emerged as one of the most promising electrode materials for high-energy lithium-ion batteries. However, limited by the slow electron/ion transport kinetics, and insufficient active sites in the bulk structure, the TiNb2O7electrode still suffers from unsatisfactory lithium storage performance. Herein, we demonstrate a spatially confined strategy toward a novel TiNb2O7-NMC/MXene composite through a triblock copolymer-directed one-pot solvothermal route, where TiNb2O7quantum dots with a particle size of 2–3 nm are evenly embedded into N-doped mesoporous carbon (NMC) and Ti3C2TXMXene. Impressively, the as-prepared TiNb2O7-NMC/MXene anode exhibits a high reversible capacity (486.2 mAh g−1at 0.1 A g−1after 100 cycles) and long cycle lifespan (363.4 mAh g−1at ss1 A g−1after 500 cycles). Both experimental and theorical results further demonstrate that such a superior lithium storage performance is mainly ascribed to the synergistic effect among 0D TiNb2O7quantum dots, 2D Ti3C2TXMXene nanosheets, and N-doped mesoporous carbon. The strategy presented also opens up new horizon for space-confined preparation of high-performance electrode materials.