Stable Conversion Mn₃O₄ Li-Ion Battery Anode Material with Integrated Hierarchical and Core–Shell Structure

Anodes composed of Mn3O4 deliver a much higher specific capacity in Li-ion batteries (LIBs) than that of commercial graphite but suffer from poor cycling stability, a poor rate characteristic, and a high overpotential stemming from volumetric changes during cycling, low electroconductibility, and insufficient ion diffusivity. To make Mn3O4 more applicable, we developed a convenient one-pot synthesis route to fabricate porous hierarchical spherical Mn3O4 with in situ coated conductive carbon (C-Mn3O4). The C-Mn3O4 shows a large capacity and good cycling stability. When assembled into anodes, this material delivered a capacity of 703 mA h g–1 in a 1000 mA g–1 cycling test after 700 cycles with only a 3% capacity decay. Meanwhile, the system provided superior rate performance with capacities of 860, 823, 760, 674, and 570 mA h g–1 at 100, 200, 500, 1000, and 2000 mA g–1, respectively. On the basis of our systematic investigations, we attribute this high electrochemical performance to the carbon reinforced porous hierarchical sphere structure.