Reduced graphene oxide anchored with MnO₂ nanorods as anode for high rate and long cycle Lithium ion batteries

Graphical abstract: A process involves two steps: modification of the surface of the MnO₂ nanorods with APTES and hydrothermal reaction of the MnO₂ nanorods/GO composites to fabricate of the MnO₂/graphene composites. Due to the intimate contact with graphene, the MnO₂/graphene composites exhibit a superior cycling performance and lithium-storage capacity. Under the current density of 0.5 A g⁻¹, the MnO₂/rGO composites electrode could deliver reversible capacities as high as 600.3 mAh g⁻¹ after more than 650 cycles. - Highlights: • MnO₂/rGO has been synthesized by modifying MnO₂ nanorods and subsequent hydrothermal. • The MnO₂/rGO can deliver excellent electrochemical performance when used in LIBs. • The intimate contact between MnO₂ and rGO leads to the high performance of MnO₂/rGO. - Abstract: The utilization of MnO₂ based anode materials is limited by poor cycling performance and low rate capacity due to chemical and mechanical degradations upon cycling. In this work, an effective strategy is implemented to mitigate the capacity fading of MnO₂ at high rates by anchoring MnO₂ nanorods on the surface of graphene. The intimate contact with graphene significantly improves the electrical conductivity of the MnO₂ composites materials. Moreover, graphene can buffer the volume changes of MnO₂ during the lithium insertion/extraction process. The MnO₂/rGO composites exhibit a superior cycling performance and lithium-storage capacity. Under the current density of 0.5 A g⁻¹, the MnO₂/rGO composites electrode could deliver reversible capacity as high as 600.3 mAh g⁻¹ after more than 650 cycles. Furthermore, at a high rate of 5 A g⁻¹, the MnO₂/rGO composites electrode can still deliver reversible specific capacity of 168.2 mAh g⁻¹.