Capacity fading of LiMn2O4 electrode synthesized by the emulsion drying method

We adapted the emulsion drying method to obtain highly crystalline spinel LiMn2O4 phase using LiNO3 and Mn(NO3)(2) . 6H(2)O as starting materials. The emulsion-dried powders were calcined at various temperatures for 24 h in air, and their crystalline phases were identified as a cubic spinel structure with the space group Fd3m by X-ray diffraction study. The initial discharge capacity of the samples calcined at 650 degrees C, 750 degrees C and 850 degrees C were approximately 120 mA h/g, irrespective of calcination temperature. However, their capacity fadings were significantly dependent on the calcination temperature. To investigate the structural changes in the oxide cathode, XRD experiment was carried out as functions of lithium content and charge-discharge cycling number. Through the SEM observation, it was found that particles were disrupted, and the degree of disruption increased with lithium content and cycling. (C) 2000 Elsevier Science S.A. All rights reserved.