We have prepared a 4.8 V voltage cathode. Li(Ni0.5Mn1.5)O-4 using the polymer polyvinylpyrrolidone (PVP) as precursor at temperatures ranging from 700 to 750 degrees C for 6 h in air. The Rietveld refined X-ray diffraction pat terns of Li(Ni0.5Mn1.5)O-4 showed a spinet type structure with a lattice parameter value of similar to 8.174(2) angstrom. The Scanning Electron Microscope (SEM) images showed particle size in the range, similar to 100-3000 nm. The surface area of the prepared powders was characterized by the Brunauer-Emmett-Teller (BET) technique. Cathodic electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic cycling (GC) in the range 3.5-5.0 V vs. Li/Li+ at ambient temperature. CV studies showed a minor peak at similar to 4.0 V due to the Mn3+/4+ redox couple, and main anodic/cathodic peaks at 4.75/4.6V and 4.8/4.7 V corresponding to the Ni2+/4+ redox couples. The GC studies were carried out at the current rates (C/4.5) 30 mAg(-1) and (C/1.2)120 mA g(-1), at room temperature. The reversible capacities of all samples prepared at 700-750 degrees C are in the range, 92-130 (+/- 3) mAh g(-1) at the end of 15th cycle. Impedance studies were carried out on a selected cell. (C) 2012 Elsevier Ltd. All rights reserved.