LiMn1.5Ni0.5O4 is synthesized by a sol–gel methodand the intercalation kinetics as positive electrode for lithiumion
batteries is investigated by EIS. LiMn1.5Ni0.5O4 particles
prepared via sol–gel process possess spinel phase with Fd-3m
space group. The charge-transfer resistance, the exchangecurrent
density and the solid-phase diffusion are found as a
function of temperature. The apparent activation energy of the
exchange current, the charge transfer, and the lithium diffusion
in solid phase are also determined, respectively. This result
indicates that the effect of the temperature on the cell capacity
and the current dependence of the capacity results mainly from
the enhancement of the lithium diffusion at elevated temperatures.
It can be concluded that LiMn1.5Ni0.5O4 cell has a bad
rate cycling performance at elevated temperatures before any
modification due to the high diffusion apparent activation
energy. The relevant theoretical elucidations thus provide us
some useful insights into the design of novel LiMn1.5Ni0.5O4-
based positive-electrode materials.
