Electrostatic Self-assembly of 0D–2D SnO(2) Quantum Dots/Ti(3)C(2)T(x) MXene Hybrids as Anode for Lithium-Ion Batteries

MXenes, a new family of two-dimensional (2D) materials with excellent electronic conductivity and hydrophilicity, have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes. Herein, a facile electrostatic self-assembly of SnO(2) quantum dots (QDs) on Ti(3)C(2)T(x) MXene sheets is proposed. The as-prepared SnO(2)/MXene hybrids have a unique 0D–2D structure, in which the 0D SnO(2) QDs (~ 4.7 nm) are uniformly distributed over 2D Ti(3)C(2)T(x) MXene sheets with controllable loading amount. The SnO(2) QDs serve as a high capacity provider and the “spacer” to prevent the MXene sheets from restacking; the highly conductive Ti(3)C(2)T(x) MXene can not only provide efficient pathways for fast transport of electrons and Li ions, but also buffer the volume change of SnO(2) during lithiation/delithiation by confining SnO(2) QDs between the MXene nanosheets. Therefore, the 0D–2D SnO(2) QDs/MXene hybrids deliver superior lithium storage properties with high capacity (887.4 mAh g(−1) at 50 mA g(−1)), stable cycle performance (659.8 mAh g(−1) at 100 mA g(−1) after 100 cycles with a capacity retention of 91%) and excellent rate performance (364 mAh g(−1) at 3 A g(−1)), making it a promising anode material for lithium-ion batteries. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-019-0296-7) contains supplementary material, which is available to authorized users.