Carbon Coated MoS2 Hierarchical Microspheres Enabling Fast and Durable Potassium Ion Storage

Potassium ion batteries (PIBs) is becoming a capable battery technology that can be used for coming generation low-cost energy storage. Although conversion-type transition metal dichalcogenides have shown major application prospects as high-capacity anode in PIBs, the dramatic structural degradation of materials during the potassium ions (de)intercalation process leads to unsatisfied cycling performance and poor rate ability. Herein, we carry out an interfacial engineering strategy to design and synthesize carbon-coated MoS2 hierarchical microspheres (MoS2@C) for PIBs. The uniform carbon coating layer maintains the structural integrity and the heterointerfaces in MoS2@C provide an electron transport highway. As a consequence, at 100 mA g-1, for the MoS2@C hierarchical microspheres, a remarkable capacity of 332 mAh g-1 can be obtained, with a remarkable cycling ability. Moreover, at 1000 mA g-1, MoS2@C can still provide the capacity of 124 mAh g-1 over 700 cycles. The kinetics analysis and ex-situ characterization demonstrated the fast and reversible K ions storage behavior of MoS2@C. This work is helpful to design other conversion-type electrode materials for metal ion storage systems.