Confining ultrafine SnS2 nanoparticles into MXene interlayer toward fast and stable lithium storage

The SnS2-based anode materials are attractive for high-energy–density lithium-ion batteries, but greatly limited by their low conductivity, large volume effects and sulfur dissolution. Here, we demonstrate the confined synthesis of ultrasmall SnS2 nanoparticles parallelly dispersed into Ti3C2 interlayer. The physical confinement effects and strong Sn-S-Ti covalent bond enable the SnS2 nanoparticles firmly anchored on Ti3C2 interlayer, which can sustain the structural integrity and refrain sulfur dissolution during de-/lithiation. Meantime, the face-to-face contact between them and the widened interlayer spacing of Ti3C2 ensure the rapid ions/electrons transfer, greatly enhancing the reaction kinetics and electrochemical reversibility. As a result, SnS2-in-Ti3C2 hybrids exhibit lithium storage capacities of 1076 and 403 mAh g−1 at 0.1 and 10 A g−1, respectively. A 88.5% capacity retention can be obtained even after 1000 cycles at 2 A g−1. This work has proposed an intriguing strategy to construct high-capacity Sn-based materials for advanced lithium-ion batteries.