3D V 2 CT x -rGO Architectures with Optimized Ion Transport Channels toward Fast Lithium-Ion Storage.

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 V 2 CT x MXene nanosheets with rGO to construct a 3D porous V 2 CT x -rGO composite. X-ray spectroscopy study reveals the close interfacial contact between V 2 CT x and rGO via electron transfer from V to C atoms. Benefiting from the close combination and optimized ion transport channel, V 2 CT x -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 V 2 CT x -rGO has implications for the study of the MXene composite's structure and energy storage devices with high rate and stability.