Morphology-controllable synthesis of spinel zinc manganate with highly reversible capability for lithium ion battery

Abstract A micro-emulsion method has been introduced to synthesize spinel ZnMn 2 O 4 . By means of a simple adjustment of the reaction solvent or added surfactant, we successfully gain distinct micro-shapes as porous hexahedron, porous microsphere and porous core-shell microsphere. XRD test results validate the phase purity of resulting ZnMn 2 O 4 materials. Interestingly, the different structural characteristics result in significant disparate electrochemical performances. The porous core-shell microsphere (PCMZ) exerts surprisingly remarkable specific capacity and excellent rate performance. The observed enormous discharge capacity of synthesized PCMZ (∼1600 mAh g −1 for the 100th cycle) is the highest among the ever reported ZnMn 2 O 4 -based material. The long cycle performance at high current rate (1208 mAh g −1 after 250 cycles at 500 mA g −1 ) is also the best. Large amount of experimental results demonstrate that the resulted high specific capacity is mainly assigned to the generation of higher valence Mn during cycling and extra interfacial Li storage caused by its unique architecture.