Stearic acid in tetramethylammonium hydroxide is used to co-precipitate lithium and manganese in stoichiometric proportions from aqueous solutions of manganese and lithium salts. Calcination of the precipitate in air produces uniformly sized, fine particles of spinel LiMn2O4 as the end product. The effect of heat treatment on the spinel formation reaction is followed by thermogravimetry and powder X-ray diffraction measurements. The electrochemical performance of the spinel is evaluated in test cells using the spinel as the positive electrode material, and lithium metal as the negative electrode. The charge–discharge data indicate that the spinel has a specific capacity of about 119 mAh g−1. The material shows good rate capability in the range of 0.5–3 mA cm−2.