Electrochemical and Thermal
Investigation of Li4/3Ti5/3O4 spinel
W. Lu, I. Belharouak, J. Liu, and K. Amine
Chemical Sciences and Engineering Division, Argonne National Laboratory
Abstract
We have studied the electrochemical and thermal properties of Li4/3Ti5/3O4
spinel as a promising anode material for lithium ion batteries. The
spinel/rock-salt two-phase transition process was interpreted using a core-shell
model, which provided a good explanation of the different area-specific
impedance behaviors during the charge and discharge processes. The constant
dE/dT during the spinel/rock-salt phase transition was calculated from the
heat-flow profile by isothermal microcalorimeter results and found to be around
-0.04 mV/K. This very low and constant entropy change indicates that
Li4/3Ti5/3O4 is a good anode material in terms of thermal stability. Also, we
propose that there is a new phase generation when more than one lithium atom is
inserted into Li4/3Ti5/3O4. According to the discontinuity of dE/dT results, the
order/disorder transition at the low-voltage region (around 0.6 V vs Li) occurs
during further lithium insertion.
Journal of the Electrochemical Society, 154(2), A114-A118 (2007)
©The Electrochemical Society 2007 |
