Synthesis of spinel LiMn2O4 microspheres with durable high rate capability
(1. School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China;
2. The Key Laboratory of Fuel Cell Technology of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China;
3. Centre for Green Products and Processing Technologies,
Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou 511458, Chi, na)
2. The Key Laboratory of Fuel Cell Technology of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China;
3. Centre for Green Products and Processing Technologies,
Guangzhou HKUST Fok Ying Tung Research Institute, Guangzhou 511458, Chi, na)
Abstract: Spinel LiMn2O4 microspheres with durable high rate capability were synthesized by a facile route using spherical MnCO3 precursors as the self-supported templates, combined with the calcinations of LiNO3 at 700 °C for 8 h. The spherical MnCO3 precursors were obtained from the control of the crystallizing process of Mn2+ ions and NH4HCO3 in aqueous solution. The effects of the mole ratio of the raw materials, reaction time, and reaction temperature on the morphology and yield of the MnCO3 were investigated. The as-synthesized MnCO3 and LiMn2O4 microspheres were characterized by powder X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Galvanostatic charge/discharge tests indicate that the spinel LiMn2O4 microspheres deliver a discharge capacity of 90 mA∙h/g at 10C rate show good capacity retention capability (75% of their initial capacity after 800 cycles at 10C rate). The durable high rate capability suggests that the as-synthesized LiMn2O4 microspheres are promising cathode materials for high power lithium ion batteries.
Key words: MnCO3 microspheres; self-supported template; LiMn2O4 microspheres; rate capability