The preparation of flowerlike ZnMn2O4 microspheres assembled with porous nanosheets and their lithium battery performance as anode materials

Abstract

In this paper, hierarchical ZnMn₂O₄ microspheres assembled with porous nanosheets have been synthesized by a facile solvothermal process and post annealing method. A possible formation mechanism for this unique structure is proposed based on a detailed time-dependent investigation. As a virtue of its beneficial structural features, the electrochemical tests of the as-synthesized hierarchical ZnMn₂O₄ microspheres exhibit an enhanced lithium storage capacity and an excellent cycling stability (662 mA h g⁻¹ at 100 mA g⁻¹ after 120 cycles). This may be attributed to their unique structural features of favoring the diffusion of Li⁺ ions and electrode–electrolyte contacts during the electrochemical reaction and enhanced structural integrity with sufficient void space for buffering the volume variation during the Li⁺ insertion and extraction. These results indicate that hierarchical ZnMn₂O₄ microspheres assembled with porous nanosheets are promising anode materials for highly reversible lithium-ion batteries.