Octahedral MoS2/CuS heterostructure confined in P-doped carbon with enhanced kinetics and stability for efficient sodium-ion storage

The unique two-dimensional layered structure and notable theoretical specific capacity of molybdenum disulfide (MoS 2 ) make it highly competitive anode materials for sodium-ion batteries (SIBs). However, its practical utility is hampered by sluggish Na + /electron transport kinetics and substantial volume changes. Herein, the successful synthesis of an ultrafine MoS 2 /CuS heterostructure embedded in a P-doped carbon framework (MoS 2 /CuS@C) is achieved via sulfurization of an octahedral bimetallic Mo/Cu-metal-organic frameworks (MOFs) precursor. The rationale for achieving superior electrochemical performance hinges on an ingenious design: the leverage of p-n heterojunctions within the carbon framework. The p-n heterojunction of ultrafine MoS 2 /CuS can powerfully drive Na + /electron transfer, thus enhancing the reaction kinetics. Concurrently, the uniform confinement of this heterostructure within the MOFs-derived carbon framework not only supplies the mechanical robustness to withstand volume variation but also creates a highly conductive network to boost overall conductivity. Hence, the MoS 2 /CuS@C anode for SIBs exhibits exceptional cycling stability, demonstrating a capacity of 528 mAh g −1 through 3000 prolonged cycles at 10 A g −1 . Furthermore, the MoS 2 /CuS@C//Na 3 V 2 (PO 4 ) 3 full cell achieves a well-maintained capacity of 44.6 mAh g −1 over 500 cycles. This work establishes a design blueprint aimed at developing efficient anodes.