Structure and electrochemical properties of Nd-doped LiMn2O4 spinel

LiMn2-xNdxO4 spinels doped with a wide range (x=0.005similar to0.1) of rare earth element (Nd) were synthesized. The result of the specific capacity dependence on x value shows that the sample with x=0.01 has the highest capacity among the samples. The structural change during cycles of LiMn2-xNdxO4(x=0.01) spinel, was studied by X-ray powder diffraction which shows that the samples maintain spinel structure and after 100 cycles the symmetry of the unit cell increases. The charge-discharge curves of, the obtained spinel show that, after 100 cycles the capacity loss is only 14.9% which shows that the structure of LiMn2-xNdxO4(x=0.01) is stable. The FTIR spectra of LiMn1.99Nd0.01O4 samples indicate that there is no intense reaction between positive material and the electrolyte, but the trace of the H+/Li+ exchange may be the cause of the little capacity loss.