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

[Display omitted] • Carbon coated MoS 2 hierarchical microspheres are synthesized with PVP assistance. • MoS 2 @C display the capacity of 124 mAh/g over 700 cycles at 1000 mA g−1 for K ion batteries. • The capacitive contribution promises the rate ability and cycling performance of MoS 2 @C. • The K ions storage mechanism in MoS 2 @C is investigated via ex-situ XRD and TEM. 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 MoS 2 hierarchical microspheres (MoS 2 @C) for PIBs. The uniform carbon coating layer maintains the structural integrity and the heterointerfaces in MoS 2 @C provide an electron transport highway. As a consequence, at 100 mA g-1, for the MoS 2 @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, MoS 2 @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 MoS 2 @C. This work is helpful to design other conversion-type electrode materials for metal ion storage systems. [ABSTRACT FROM AUTHOR]