Electrochimica Acta, Vol.152, 274-279, 2015
Preparation and Characterization of Ultralong Spinel Lithium Manganese Oxide Nanofiber Cathode via Electrospinning Method
Aim: ng at improving the high rate capability of spinel lithium manganese oxide (LiMn2O4) cathode, ultralong LiMn2O4 nanofibers are prepared by combination of electrospinning and sol-gel techniques. The effect of processing parameters, including the weight ratio of polyvinylpyrrolidone (PVP) to Li and Mn precursor, calcination temperature and time, on the morphology and the resultant cathode performance of spinel LiMn2O4 nanofiber cathodes have been systematically investigated. Thermal behavior of LiMn2O4 precursor nanofibers is performed on a differential scanning calorimetry-differential thermal analysis (DSC-DTA), indicating the spinel LiMn2O4 began forming at 513 degrees C. The cathode materials appear porous "network-like" morphology with nanosize in diameter (similar to 170 nm), microsize in length (similar to 20 mu m) and pure spinel structure, confirmed by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The ultralong LiMn2O4 nanofiber cathode calcined at 700 degrees C for 8 h shows highest capacity and best rate capability. Its discharge capacity is 146 mAhg(-1) at 0.1 C; more importantly, the discharge capacities are 112 mAhg(-1), 103 mAhg(-1) and 92 mAhg(-1) at high discharge rates of 10 C, 20 C and 30 C, respectively. (C) 2014 Elsevier Ltd. All rights reserved.