Spinel lithium manganese oxide, LiMn2O4, prepared by the sol–gel method using citric acid as a chelating agent under different (i) pH conditions, (ii) molar ratio of citric acid to total metal ion, (iii) amount of water, (iv) calcination temperature, and (vi) starting materials. The effects of various synthetic parameters on the purity of this oxide are analysed by means of X-ray diffraction measurements. The results show that pure LiMn2O4 can be prepared from nitrate salts as starting materials at a low temperature of 600°C. The optimum pH and molar ratio of chelating agent to total metal ions are 6.0 and 1.0, respectively.