Hierarchical porous ZnMn₂O₄ microspheres assembled by nanosheets for high performance anodes of lithium ion batteries

Hierarchical porous ZnMn₂O₄ microspheres assembled by nanosheets with an average thickness of several nanometers are successfully synthesized by a facile hydrothermal method and subsequent calcination at 500 °C in air. When used as an anode electrode of lithium ion batteries (LIBs), the ZnMn₂O₄ microspheres exhibit a high discharge capacity of 1132 mA h g^-1 after 500 cycles at a current density of 500 mA g^-1 and excellent rate capability. It is believed that the outstanding electrochemical performance benefits from the hierarchical porous structure that can not only increase the contact area between the electrode and the electrolyte to facilitate the transfer of Li⁺ ions, but also provide sufficient space for volume expansion of the electrode during the cycling process.