Formation of quasi-mesocrystal ZnMn2O4 twin microspheres via an oriented attachment for lithium-ion batteries†
Abstract
At present, transition metal oxides (TMOs) have generally been fabricated via annealing carbonates pre-obtained by a precipitation/solvothermal route. We noted that researchers mainly focused on how to get the expected TMOs through calcination. However, study about the formation process of the corresponding precursors is rarely investigated. Instead, it is of much importance for the development of materials chemistry. Herein, as an example, for the first time, we devise a facile polyol-based method to synthesize the quasi-mesocrystal ZnMn2O4 porous twin-microspheres. Formation chemistry and electrochemical properties of the twin spheres have been investigated in detail. A distinctive oriented attachment accompanied by Ostwald ripening is proposed to understand the formation of the 3D carbonate twin microspheres, providing a new research opportunity for investigating the formation of novel micro/nanostructures. Benefitting from the many unique structural advantages, including quasi-mesocrystal architecture, 3D hierarchical porous microstructure, and lithium alloying reaction, the as-prepared ZnMn2O4 twin spheres represent remarkable lithium storage properties when evaluated as anode materials for lithium-ion batteries (LIBs), with high capacity, long cycle life and remarkable rate capability. The 3D porous hierarchical structures demonstrate great potential as anode materials for high-performance LIBs.