Characterization and Electrochemical Properties of LiMn_2O_4 Thin Films Prepared by Solution Deposition

摘要

LiMn_2O_4 thin films were prepared by solution deposition using lithium acetate and, manganese acetate as raw materials The phase constitution and surface morphology were observed by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were studied by cyclic vollamrnetry, charge-discharge experiments and impedance spectroscopy in 1 mol centre dot L~(-1) LiPF_6/EC-DMC solution using lithium metal as both the counter and reference electrodes. The films prepared by this method are of spinel phase The lattice parameter increases with the annealing temperature and annealing time. The film annealed at 750 deg C for 30 minutes has the highest capacity of 34.5 mu Ah centre dot cm~(-1) centre dot mu m~(-1), and its capacity loss per cycle is 0.05 percent after being cycled 100 times.