A novel self-assembled-derived 1D MnO₂@Co₃O₄ composite as a high-performance Li-ion storage anode material

Manganese dioxide (MnO₂) is a high-performance anodic material and applied widely in lithium-ion batteries (LIBs). However, some intrinsic limitations originate from the low ionic conductivity, high polarization, and severe volume expansion of this type of material. In this work, we generated a one-dimensional porous MnO₂@Co₃O₄ composite from a MnOOH@ZIF-67 precursor, which is synthesized via a self-assembly strategy. The one-dimensional porous structure provided more active sites and shorter-ion/electron-diffusion distance, thereby enabling higher Li⁺ storage capacity and better rate capability than a transition metal oxide alone. The Co₃O₄ coating buffered the volume change during Li⁺ insertion/extraction, leading to increased cycling stability of the electrode. When evaluated as the anode of LIBs, MnO₂@Co₃O₄ exhibited a reversible capacity of 647 mA h g^-1 at 2000 mA g^-1 after 400 cycles. This excellent performance indicated that the MnO₂@Co₃O₄ material could be an attractive potential candidate for Li⁺ storage.