LiMn2O4nanopowders synthesized via gelatin-assisted sol–gel method: Optimization of pH and calcination temperature

In this research, LiMn 2 O 4 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 LiMn 2 O 4 was completely formed without any impurity phase at a calcination temperature of 750[Formula: see text]C. The peak intensity ratio of I[Formula: see text]/I[Formula: see text], which presents the stability of LiMn 2 O 4 structure, is bigger for the sample with pH[Formula: see text]=[Formula: see text]4 than that of the samples with pH[Formula: see text]=[Formula: see text]7 and 8. The sample with pH[Formula: see text]=[Formula: see text]4 has smaller particles of about 70 nm, with more homogeneity and less agglomeration than that of the other samples. At calcination temperature to 850[Formula: see text]C, the size of the particles has become bigger and the particle surfaces show more clarity in all samples. The effect of the pH value on electrochemical properties was studied by galvanostatic charge/discharge tests. The results show more capacity lost for the sample with pH[Formula: see text]=[Formula: see text]8 with regards to the other samples.