3D V₂CT_<i>x</i>–rGO Architectures with Optimized Ion Transport Channels toward Fast Lithium-Ion Storage

Abstract

Two-dimensional (2D) MXene materials show great potential in energy storage devices. However, the self-restacking of MXene nanosheets and the sluggish lithium-ion (Li⁺) kinetics greatly hinder their rate capability and cycling stability. Herein, we interlink 2D V₂CT_<i>x</i> MXene nanosheets with rGO to construct a 3D porous V₂CT_<i>x</i>-rGO composite. X-ray spectroscopy study reveals the close interfacial contact between V₂CT_<i>x</i> and rGO via electron transfer from V to C atoms. Benefiting from the close combination and optimized ion transport channel, V₂CT_<i>x</i>-rGO offers a high-rate Li⁺ storage performance and excellent cycling stability over 2000 cycles with negligible capacity attenuation. Moreover, it exhibits a dominant mechanism of intercalation pseudocapacitance and efficient Li⁺ transport proved by density functional theory calculation. This rationally designed 3D V₂CT_<i>x</i>-rGO has implications for the study of the MXene composite's structure and energy storage devices with high rate and stability.