Skip to main content Accessibility help
×
Home

Solid State Synthesis and Properties of Doped LiMnO2 Cathode Materials

  • B. Ammundsen (a1), J. Desilvestro (a1), T. Groutso (a2), D. Hassell (a1), J. B. Metson (a2), E. Regan (a2), R. Steiner (a1) and P. J. Pickering (a1)...

Abstract

The crystal structures, microstructures and electrochemical properties of Al-doped lithium manganese oxide materials LiAl x Mn1−x O2 (0 ≤ x ≤ 0.1) prepared by solid state reactions have been investigated. A1 doping results in increased cation disorder in the orthorhombic polymorph of LiMnO2, and produces layered monoclinic LiMnO2 with an α-NaFeO2 type crystal structure. The formation of monoclinic LiAl x Mn1-x O2 confirms earlier observations by Chiang et al. [1,2]. A mechanism is proposed for the orthorhombic-monoclinic transformation, based on Li-Mn inversion in the orthorhombic structure. Al ions substitute in Mn sites in the monoclinic phase and give rise to microstrain in the [2 0 -l] planes. Microstructural analysis by scanning electron microscopy has revealed Al-deficient striations which may represent residual zones of orthorhombic phase. In cycling tests in Li button cells, increasing the amount of Al dopant extends the number of cycles required for the capacity to evolve to its maximum value, but results in increased stability of the capacity at 55 °C. The layered structure of the monoclinic materials is retained on the first cycle, but transforms to a spinel-type structure on extended cycling.

Copyright

References

Hide All
1. Jang, Y.-I., Huang, B., Chiang, Y.-M. and Sadoway, D.R., Electrochem. Solid State Lett. 1, 13(1998).
2. Chiang, Y.-M., Sadoway, D.R., Jang, Y.-I., Huang, B. and Wang, H., Electrochem. Solid State Lett. 2, 107(1999).
3. Blyr, A., Sigala, C., Amatucci, G., Guyomard, D., Chabre, Y. and Tarascon, J.-M., J. Electrochem. Soc. 145, 194(1998).
4. Gummow, R.J., Liles, D.C. and Thackeray, M.M., Mater. Res. Bull. 28, 1249(1993).
5. Ohzuku, T., Ueda, A. and Hirai, T., Chem. Express 7, 193(1992).
6. Reimers, J.N., Fuller, E.W., Rossen, E. and Dahn, J.R., J. Electrochem. Soc. 140, 3396(1993).
7. Koetschau, I., Richard, M.N., Dahn, J.R., Soupart, J.B. and Rousche, J.C., J. Electrochem. Soc. 142, 2906(1995).
8. Davidson, I.J., McMillan, R.S., Murray, J.J. and Greedan, J.E., J. Power Sources 54, 232(1995).
9. Armstrong, A.R. and Bruce, P.G., jNature 381, 499(1996).
10. Capitaine, F., Gravereau, P. and Delmas, C., Solid State Ionics 89, 197(1996).
11. Tabuchi, M., Ado, K., Kobayashi, H., Kageyama, H., Masquelier, C., Kondo, A. and Kanno, R., J. Electrochem. Soc. 145, L49 (1998).
12. Vitins, G. and West, K., J. Electrochem. Soc. 144, 2587(1997).
13. Rodriguez-Carjaval, J., Fullprof Manual. Institut Laue-Langevin, Grenoble, 1992.
14. In trivalent manganese compounds, a tetragonal distortion occurs in the octahedral coordination of the Mn3+ d4 ions due to the Jahn-Teller stabilisation of the electronic structure, which produces two axial Mn-O bonds of ca. 2.3 Å and four equatorial bonds of ca. 1.9 Å. In LiMnO2 materials, the crystal structures adapt to this localised distortion through a cooperative effect where all the long bonds are orientated along the same crystal direction.
15. Croguennec, L., Deniard, P., Brec, R. and Lecerf, A., J. Mater. Chem. 7, 511(1997).
16. Carver, J.C., Schweitzer, G.K. and Carlson, T.A., J. Chem. Phys. 57 973(1972).
17. Benson, R. and Metson, J.B., in European Conference on Applications of Surface and Interface Analysis, edited by Mathieu, H.J., Reihl, B. and Briggs, D. (John Wiley & Sons, Chichester, 1996), pp. 373376.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed