A comprehensive study on influence of Nd3 + substitution on properties of LiMn2O4

LiNdxMn2 − xO4 samples are synthesized via co-precipitation technique. The activation energies computed from thermogravimetric analyses on the basis of Ozawa method have been observed to linearly increase with increase in dopant concentration. X-ray diffraction analyses indicate the cubic–spinel structure for all the samples. The lattice parameter has been observed to decrease with increasing concentration of Nd3 + doping. The octahedral site preference of neodymium dopant in the LiMn2O4 structure has been elucidated using XRD and FT–IR studies. The porosity and surface roughness obtained from SEM analysis have been observed to decrease with increase in Nd3 + dopant concentration in LiMn2O4 lattice. The electrochemical performances of the electrodes were analysed through cyclic voltammetry, chronopotentiometry and electrochemical impedance techniques. The specific capacity has been observed to decrease initially with increase in Nd3 + dopant concentration, whereas the capacity retention has increased with increase in dopant concentration. The observed percentage capacity retention after 50 cycles of the electrodes LiNd0·05Mn1·95O4, LiNd0·10Mn1·90O4 and LiNd0·15Mn1·85O4 were 88·4%, 97·1% and 96·8%, respectively. The Li ion diffusion coefficient ascertained using electrochemical impedance spectroscopy was found to be higher for LiNd0·10Mn1·90O4 around 3·74 × 10 − 12 cm2 s − 1.