Abstract:

LiMn_2-xNd_xO₄ spinels doped with a wide range (x=0.005～0.1) 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 LiMn_2-xNd_xO₄(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 LiMn_2-xNd_xO₄(x=0.01)
is stable. The FTIR spectra of LiMn_1.99Nd_0.01O₄ 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.

Key words: doping, lithium-ion batteries, spinel