Spatially confined synthesis of TiNb2O7 quantum dots onto mesoporous carbon and Ti3C2TX MXene for boosting lithium storage

• Published in: Green energy & environment
• Main Authors: Sun, Daoguang, Tang, Cheng, Li, Haitao, Zhang, Xinlin, Zhu, Guanjia, Huang, Zhen-Dong, Du, Aijun, Zhang, Haijiao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2024
• Subjects: Confined synthesis; Lithium-ion batteries; Mesoporous carbon; Ti3C2TX MXene; TiNb2O7 quantum dots; Lithium-ion batteries; TiNb2O7 quantum dots; Ti3C2TX MXene; Mesoporous carbon; Confined synthesis
• ISSN: 2468-0257; 2468-0257
• DOI: 10.1016/j.gee.2024.03.004

TiNb2O7 has 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 TiNb2O7 electrode 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 TiNb2O7 quantum dots with a particle size of 2–3 nm are evenly embedded into N-doped mesoporous carbon (NMC) and Ti3C2TX MXene. Impressively, the as-prepared TiNb2O7-NMC/MXene anode exhibits a high reversible capacity (486.2 mAh g−1 at 0.1 A g−1 after 100 cycles) and long cycle lifespan (363.4 mAh g−1 at ss1 A g−1 after 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 TiNb2O7 quantum dots, 2D Ti3C2TX MXene nanosheets, and N-doped mesoporous carbon. The strategy presented also opens up new horizon for space-confined preparation of high-performance electrode materials. A ternary TiNb2O7-NMC/MXene composite has been developed by a triblock copolymer-directed solvothermal assembly route, where ultrasmall TiNb2O7 quantum dots are spatially confined into N-doped mesoporous carbon and Ti3C2Tx MXene nanosheets. The resulting TiNb2O7-NMC/MXene anode shows an excellent electrochemical lithium storage capability. [Display omitted] •A spatially confined strategy was used to prepare a ternary TiNb2O7-NMC/MXene composite.•Ultrasmall TiNb2O7 quantum dots were evenly embedded into N-doped mesoporous carbon and Ti3C2TX MXene.•The obtained TiNb2O7-NMC/MXene anode exhibited the improved lithium storage capability.