Cu 1.81 S/CoS 2 heterostructure confined by MXenes for high capacity sodium-ion battery anodes

Cu 1.81 S/CoS 2 heterojunctions optimize the interface states and accelerate Na + migration. The MXene-confined Cu 1.81 S/CoS 2 mitigates volume expansion during charging cycles; thus, MXene/Cu 1.81 S/CoS 2 @C delivers outstanding electrochemical performance.