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.