Facile microemulsion synthesis of mesoporous ZnMn2O4 submicrocubes as high-rate and long-life anodes for lithium ion batteries

In this work, monodispersed mesoporous ZnMn2O4 submicrocubes constructed of interconnected nanoparticles have been fabricated by pyrolysis of the Zn1/3Mn2/3CO3 precursor obtained through a precipitation reaction in the water-n-pentanol-CTAB-n-hexane microemulsion. The effects of microemulsion composition on the morphology and size of Zn1/3Mn2/3CO3 are investigated. The uniform ZnMn2O4 cubes obtained in the optimized microemulsion system have an average edge length of ca. 250 nm, consisting of primary nanoparticles approximately 20-40 nm in size. When served as anode for lithium ion batteries, the mesoporous ZnMn2O4 maintains a large discharge capacity of 1138 mA h g(-1) at 0.5 A g(-1 )after 600 cycles as well as a stable discharge capacity of 597 mA h g(-1) at 6 A g(-1) after 1000 cycles. The remarkable high-rate and long-cycle performances could be attributed to the small size of secondary/primary particles and robust 3D mesoporous structure, which are favorable for the improvement of electrochemical kinetics and the structural integrity of electrode during cycling. Additionally, this facile synthetic technique may be explored to prepare other submicron-sized metal oxides materials.