In this research, LiMn2O4 nanopowders were synthesized via sol-gel method using gelatin as a novel chelating agent. The effect of temperature and pH on the structure, morphology and particle size of synthesized powders has been investigated by the differential thermal analysis -DTA-, the X-ray diffraction -XRD-, the Fourier transform infrared -FTIR-, and the field-emission scanning electron microscope -FESEM-. The crystal structure of LiMn2O4 has completely formed without any impurity phase at a calcination temperature of 750 ˚C. The peak intensity ratio of I400/I311, which presents the stability of LiMn2O4 structure, is bigger for the sample with pH= 4 than that of the samples with pH= 7 and 8. The sample with pH= 4 has smaller particles about 70 nm with more homogeneity and less agglomeration than that of the other samples. At calcination temperature to 850 ˚C, the size of particles, has become bigger and the particle surfaces show more clarity in all samples. The effect of pH value on electrochemical properties was studied by galvanostatic charge/discharge tests. The results show more capacity lost for the sample with pH=8 regards to the other samples.

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