Neutron and X-Ray Diffraction Studies of LiMn2O4 Nano Material and its Electrochemical Performance

Nano materials are rather difficult to study due to their tiny particle size. This work presents a simple way of preparing LiMn2O4 nano powders using the high energy ball milling method. The preparation uses highly crystalline LiMn2O4 which has been earlier synthesized and optimized using the sol-gel method. The milling method is carefully controlled to avoid unwanted chemical reactions that may change the stoichiometry of the material. Nano powders of between 30 to 50 nm are obtained. Structural studies of the nano powders as well as the more conventional micron sized LiMn2O4 are made using X-ray, neutron and selected area electron diffraction methods. Electrochemical characterization of the materials are done using a three probe cyclic voltammetry technique and galvanostatic charge-discharge measurements. It is found that the performance characteristics of the nano material show an improvement over that of the micron sized material by about 17% in the first cycle and 70.6% in the fifth cycle. (author)