Hierarchical heterostructure of interconnected ultrafine MnO2 nanosheets grown on carbon-coated MnO nanorods toward high-performance lithiumion batteries

A new hierarchical MnOx-based nanorods consisting of interconnected MnO2 nanosheets grown on carbon-coated MnO nanorod, resembling a unique triple-co-axial heterostructure of MnO2@C@MnO, is successfully designed and prepared by a simple and controllable approach involving subsequent hydrothermal reaction, polydopamine-derived carbon coating and chemical deposition processes. Owing to its unique well-designed architecture with the structural characteristics including interconnected MnO2 nanosheets external wall, self-supported MnO nanorod core, and a high conductivity carbon interlayer sandwiched between them, each component play a critical role for the stable application of this MnOx-based nanocomposite anode toward high-performance lithium-ion batteries. The triple-co-axial MnO2@C@MnO nanocomposite shows excellent lithium-storage capabilities with the high reversible specific capacity of 919.2 mA h g(-1) at 200 mA g(-1) after 100 cycles, good rate performance (387.9 mA h g(-1) at 2 A g(-1)) and an outstanding specific capacity (1243.2 mA h g(-1)) at the rate of 1 A g(-1) after long-term cycles (900 cycles), making it a promising anode material for high-performance lithium-ion batteries.