Cubic spinel nano-crystalline LiSr x Mn2− x O4 (x =0.10, 0.15, 0.20, 0.25) powders are prepared at low temperature by means of a facile gel-polymer thermolysis process by calcining the prepared precursor samples at 340°C to obtain the products. X-ray diffraction and scanning electron microscopic analyses confirm that the products consists of nano-crystalline particles with uniform distribution. The effect of calcinations on the crystallinity of the cubic spinel LiSr x Mn2− x O4 powder is examined by differential scanning colorimetric analysis. In order to asses the electrochemical reversibility of the cathode material, cyclic voltametry studies are performed by fabricating button cells with the configuration of carbon/MPPE/LiSr x Mn2− x O4.