3D d-Ti3C2 xerogel framework decorated with core-shell SnO2@C for high-performance lithium-ion batteries

Three-dimensional (3D) delaminated-Ti3C2 (d-Ti3C2) xerogel framework decorated with core-shell SnO2@C nanoparticles is constructed via PVA-assisted sol-gel process, in which SnO2@C nanoparticles are synthesized by one-step hydrothermal route and then encapsulated into d-Ti3C2 framework. Remarkable improvement in the electrochemical performances as the lithium-ion batteries (LIBs) anode is achieved. Typically, the SnO2@C/d-Ti3C2 xerogel framework delivers a high initial capacity (1314 mA h g−1) and a reversible specific capacity up to 520 mA h g−1 after 1000 charge-discharge cycles at 1.0 A g−1. Furthermore, even at 10 A g−1, it still achieves a reversible specific capacity of 205.6 mA h g−1, with a discharge capacity of 169 mA h g−1 and a coulombic efficiency of 99.5% after 1000 cycles. Such excellent electrochemical performances are attributed to the synergistic effect between core-shell SnO2@C and 3D d-Ti3C2 conductive network: (i) the core-shell structure suppresses the pulverization of SnO2 during the Li insertion/extraction process, and (ii) the interconnected 3D MXene framework establishes a good conductive pathway for fast lithium ions diffusion and quick charge transfer.