CoMn₂O₄ Spinel Hierarchical Microspheres Assembled with Porous Nanosheets as Stable Anodes for Lithium-ion Batteries

摘要

Herein, we report the feasibility to enhance the capacity and stability of CoMn₂O₄ anode materials by fabricating hierarchical mesoporous structure. The open space between neighboring nanosheets allows for easy diffusion of the electrolyte. The hierarchical microspheres assembled with nanosheets can ensure that every nanosheet participates in the electrochemical reaction, because every nanosheet is contacted with the electrolyte solution. The hierarchical structure and well interconnected pores on the surface of nanosheets will enhance the CoMn₂O₄/electrolyte contact area, shorten the Li+ ion diffusion length in the nanosheets, and accommodate the strain induced by the volume change during the electrochemical reaction. The last, hierarchical architecture with spherical morphology possesses relatively low surface energy, which results in less extent of self-aggregation during charge/discharge process. As a result, CoMn₂O₄ hierarchical microspheres can achieve a good cycle ability and high rate capability.. ? 2012 Macmillan Publishers Limited. All rights reserved