Fast ion/electron transport enabled by MXene confined bimetallic sulfides with heterostructure toward highly effective lithium/sodium storage

Designing and constructing electrochemically reversible and stable anode materials is crucial in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Presently, the unsatisfactory transport kinetics still limits its further commercial applications. Therefore, scientific structural optimization and surface modification are urgently needed to solve this puzzle. Herein, bimetallic sulfides with heterostructure confined in MXene nanosheets (VS4/SnS2@MXene) are successfully synthesized. The distinguished electrochemical properties combined with the theory calculation confirm that the establishment of the heterogeneous interface effectively speeds up the transit of ions and electrons, enhancing the reaction kinetics of the electrode. In addition, the flexible MXene boosts the conductivity of the electrodes while mitigating volume expansion. Surprisingly, LIBs can attain an acceptable capacity of 898 mA h g−1 at 5 A/g. Additionally, a full cell with the VS4/SnS2@MXene anode has a thrilling reversible capacity of 125 mA h g−1 at 0.5 C. Furthermore, it performs better in SIBs (187 mA h g−1 at 5 A/g) as well. An innovative idea for producing metal sulfide anode materials is presented in this paper.