Hostname: page-component-7479d7b7d-68ccn Total loading time: 0 Render date: 2024-07-10T23:19:43.393Z Has data issue: false hasContentIssue false
  • English
  • Français

Molecular Dynamics Study of Lithium Diffusion in Lithium-Manganese Spinel Cathode Materials

Published online by Cambridge University Press:  10 February 2011

Randall T. Cygan ,
Henry R. Westrich  and
Daniel H. Doughty
Randall T. Cygan
Affiliation:
Sandia National Laboratories, Geochemistry Department, Albuquerque, NM 87185–0750
Henry R. Westrich
Affiliation:
Sandia National Laboratories, Geochemistry Department, Albuquerque, NM 87185–0750
Daniel H. Doughty
Affiliation:
Sandia National Laboratories, Lithium Battery Research and Development Department, Albuquerque, NM 87185–0613
Get access

Abstract

A series of molecular dynamics computer simulations of the self-diffusion of lithium in pure and several doped lithium-manganese spinel materials has been completed. The theoretical approach is part of an effort to understand the mechanisms and rates of lithium diffusion, and to evaluate the structural control of the cathode materials upon lithium intercalation (charge-discharge) process. The molecular dynamics approach employs a fully ionic forcefield that accounts for electrostatic, repulsive, and dispersion interactions among all ions. A reference unit cell comprised of 56 ions (Li8Mn3+8Mn4+8O32) is used to perform the simulations under constant volume and constant pressure constraints. All atomic positions are allowed to vary during the simulation. Simulations were completed for the undoped and doped LiMn2O4 at various levels of lithium content (based on the number of lithium ions per unit cell and manganese oxidation state). The molecular dynamics results indicate an activation energy of approximately 97 kJ/mole for self-diffusion of lithium in the undoped material. Lithium ion trajectories from the simulations provide diffusion coefficients that decrease by a factor of ten as the cathode accumulates lithium ions during discharge. Molecular dynamics results for the doped spinel suggest a decrease in the diffusion rate with increasing dopant ion.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 496: Symposium Y – Materials For Electrochemical Energy Storage & Conversion II… , 1997 , 109
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Cygan, R.T., Westrich, H.R., Doughty, D.H., in Materials for Electrochemical Energy Storage and Conversion-Batteries, Capacitors and Fuel Cells, edited by Doughty, D.H., Vyas, B., Takamura, T., and Huff, J.R., (Mater. Res. Soc. Proc. 393, Pittsburgh, PA, 1995) pp. 113–118.Google Scholar
2. Miura, K., Yamada, A., and Tanaka, M., Electrochim. Acta. 41, 249 (1996).10.1016/0013-4686(95)00304-WGoogle Scholar
3. Voigt, J.A., Boyle, T.J., Doughty, D.H., Hernandez, B.A., Johnson, B.J., Levy, S.C., Tafoya, C.J., and Rosay, M., in Materials for Electrochemical Energy Storage and Conversion-Batteries, Capacitors and Fuel Cells, edited by Doughty, D.H., Vyas, B., Takamura, T., and Huff, J.R., (Mater. Res. Soc. Proc. 393, Pittsburgh, PA, 1995) pp. 101–106.Google Scholar
4. Xie, L., Fouchard, D., D., , and Megahed, S., in Materials for Electrochemical Energy Storage and Conversion-Batteries, Capacitors and Fuel Cells, edited by Doughty, D.H., Vyas, B., Takamura, T., and Huff, J.R., (Mater. Res. Soc. Proc. 393, Pittsburgh, PA, 1995) pp. 285–304.Google Scholar
5. Gale, J. D., J. Chem. Soc, Faraday Trans., 93, 629 (1997).Google Scholar
6. Mosbah, A., Verbaere, A., and Tournoux, M., Mater. Res. Bull. 18, 1375 (1983).Google Scholar