Nanocrystalline spinel LiMn2O4 powder (LMO) was synthesized by a modified resorcinol-formaldehyde route. The effect of the calcination temperature on the physicochemical properties of the LiMn2O4 was investigated by using XRD, FESEM, BET and electrochemical measurements. Nanocrystalline spinel LiMn2O4 cathode material was shown to enhance rate capability of the cell. For optimum synthesis, the spinel LiMn2O4 showed that the optimal heat treatment protocol was 10 h calcination at 650 degrees C, which had 50-120 nm nano-sized particles with an average crystallite size of 47 nm and exhibited the best electrochemical performance (136.9 mAh g(-1) at 0.2 C and 100.9 mAh g(-1) at 60 C). Compared with the samples calcined at lower temperature (550 and 650 degrees C), the samples calcined at higher temperature (750 and 850 degrees C) had submicron-sized particles and poorer electrochemical performance. The investigations concluded that the LiMn2O4 with nano-sized particles were good for better electrochemical performance, especially for high rate capacity. Thus, it was very effective to synthesize the nanocrystalline LiMn2O4 with high rate capacity using a modified resorcinol-formaldehyde route by choosing the proper calcination temperature. (C) 2010 Elsevier B.V. All rights reserved.