Surfactant-assisted synthesis of LiMn2O4 particles as high-rate and long-life cathode materials for lithium-ion batteries

摘要

Herein, we reported the synthesis of uniform LiMn2O4 submicroparticles by surfactant-assisted preparation of spherical MnCO3 precursor followed by solid-state reaction. Polyethylene glycol (Mw = 1000) was used as surfactant to control the morphology and size of the MnCO3 precursor as well as the MnO2 intermediate and LiMn2O4 product. The influence of particle size, homogeneity, and crystallinity on the electrochemical performance of LiMn2O4 was intensively investigated. The test results indicate that the LiMn2O4 sample using polyethylene glycol with weight as 10% of reactants shows the best rate capability and long-term cyclability. Due to the homogeneous particles with the average size of ca. 250 nm and high crystallinity, the discharge capacities are as high as 125, 118, 114, and 100 mAh g(-1) at 1, 10, 20, and 50 C rates, respectively, along with high capacity retention of 74% after 1000 cycles at 20 C.