Europhys. Lett.
Volume 67, Number 1, July 2004
Page(s) 28 - 34
Section Atomic and molecular physics
Published online 01 June 2004
Europhys. Lett., 67 (1) , pp. 28-34 (2004)
DOI: 10.1209/epl/i2004-10049-1

Ab initio molecular-dynamics studies on $\chem{Li}$ x $\chem{Mn_2O_4}$ as cathode material for lithium secondary batteries

C. Y. Ouyang1, 2, S. Q. Shi1, Z. X. Wang1, H. Li1, X. J. Huang1 and L. Q. Chen1

1  Laboratory for Solid State Ionics, Institute of Physics Chinese Academy of Science - P.O. Box 603, Beijing 100080, PRC
2  Physics Department, Jiangxi Normal University - Nanchang 330027, PRC

(Received 2 February 2004; accepted in final form 3 May 2004)

Structural and dynamic properties of spinel $\chem{LiMn_2O_4}$ are investigated firstly from ab initio molecular-dynamics (MD) calculations. This method included all the interactions among the ions so that more reliable results have been obtained comparing with the conventional classical MD simulations. Full MD simulations are performed to study the structural and diffusive properties while selective MD simulations are performed to study the migration energy barrier of $\chem{Li}$ ions. Results indicate that $\chem{Li}$ ions tend to take one fcc sub-lattice in the $\chem{Li_{0.5}Mn_2O_4}$ crystal. The migration energy barriers of $\chem{Li}$ ions from one 8a site to another nearest-neighbor 8a site are about 0.23 and 0.61 $\un{eV}$ for $\chem{LiMn_2O_4}$ and $\chem{Li_{0.5}Mn_2O_4}$, respectively.

31.15.Ar - Ab initio calculations.
71.15.Pd - Molecular dynamics calculations (Car-Parrinello) and other numerical simulations.
82.47.Aa - Lithium-ion batteries.

© EDP Sciences 2004