Coordination polymer-derived hierarchically structured MnO/NC composites as anode materials for high-performance lithium-ion batteries

Coordination polymer-derived metal oxides/carbon composites have advantages of uniform carbon coating, strong bonding ability with active materials, and in-situ introduction of heteroatom-doped carbon, which make them suitable for lithium-ion battery anode materials, and they have been extensively studied. However, it is still a challenging task to design and synthesize metal oxide/heteroatom-doped carbon composites with special morphology. In this work, flower-like Mn-based coordination polymers con-structed by nanosheets, which were designed and synthesized by adjusting the coordination mode of li-gands. The hierarchical structured MnO/NC composites were successfully synthesized by calcination in reducing atmosphere. The composite exhibits a unique yolk-shell structure, the yolk-shell structure composed of micro-flowers assembled from nitrogen-doped carbon nanosheets uniformly loaded with MnO nanoparticles as the outer shell and MnO/NC nanoparticle aggregates as the inner core. It exhibits high specific capacity (1108.9 mAh g-1 after 300 cycles at 0.5 A g-1), and excellent long cycle stability (768 mAh g-1 after 1000 cycles at 1 A g-1). The outstanding Li-storage performance is owing to the sy-nergistic effect of unique yolk-shell structure and continuous nitrogen-doped carbon coating, which makes the spread of electrolyte and the transport of Li+ faster, alleviates the volume change of the electrode material during cycling, and increases the pseudo-capacitance behavior.(c) 2023 Elsevier B.V. All rights reserved.