Tailoring ceramics for specific applications: A case study of the development of all-solid-state lithium batteries
- 563 Downloads
Metal oxides with the nominal chemical compositions Li5La3M2O12 (M=Nb, Ta), possessing a garnet-like structure, exhibit ionic bulk conductivities of the order of magnitude of ∼10−6 S/cm at 25 °C. Partial substitution of La by alkaline earth elements (Ca, Sr, Ba) in Li5La3M2O12 yields new members of compounds with garnet-like structure with the composition Li6ALa2M2O12 (A=Ca, Sr, Ba). Among the investigated compounds, so far, the Ba-compound Li6BaLa2Ta2O12 exhibits the highest bulk conductivity of 4.0×10−5 S/cm at 22 °C with an activation energy of 0.40 eV. All Ta-members were found to be stable against chemical reaction with molten elemental lithium. Li6ALa2Ta2O12 (A=Sr, Ba) exhibit also high electrochemical stability of ∼6 V vs. lithium and chemical stability against reaction with LiCoO2 cathode material.
A novel high voltage thin-film battery was constructed using spinel-type Li2MMn3O8 (M=Co, Fe) as positive electrode, LiPON as electrolyte and Al as negative electrode material. Li2MMn3O8 (M=Fe, Co) electrodes show two reversible plateaus during the charging and discharging cycle at ∼4 and ∼5 V vs. Li. The former plateau is due to the valence change of Mn3+ to Mn4+ and the latter one is due to the oxidation of M3+ to M4+. The chemical diffusion coefficient (\(\tilde D\)) was found to be in the range 10−13–10−12 cm2/sec for any composition x of Li2−xMMn3O8 (M=Fe, Co) in the range from 0.1 to 1.6 by employing the galvanostatic intermittent titration technique (GITT). AC impedance studies revealed an electrolyte-electrode charge transfer resistance of 260–290 Θ and an electrode double layer capacity of ∼45–70 µF for an electrode area of 6.7 cm2 at room temperature. The chemical diffusion coefficient of the Al,LiAl negative electrode is about three orders of magnitude higher than that of the positive electrode materials. Accordingly, we believe that the diffusion of Li into and out of the cathode material is the rate determining process.
KeywordsCathode Material Negative Electrode Positive Electrode Bulk Conductivity Alkaline Earth Element
Unable to display preview. Download preview PDF.
- Solid Electrolytes General Principles, Characterization, Materials, Applications (P. Hagenmuller and W. Van Gool, Eds), Academic Press, New York, 1978.Google Scholar
- C. Julien and G.A. Nazri, Solid State Batteries: Materials Design and Optimization, Kluwer Academic Publishers, Boston, 1994.Google Scholar
- Solid State Electrochemistry, (P.G. Bruce, Ed), Cambridge University Press, Cambridge, 1995.Google Scholar
- Lithium Ion Batteries Fundamentals and Performace, (M. Wakihara and O. Yamamoto, Eds.), Wiley-VCH, Berlin, 1998.Google Scholar
- Handbook of Battery Materials, (J.O. Besenhard, Ed.), Wiley-VCH, Berlin, 1999.Google Scholar
- V. Thangadurai and W. Weppner, J. Power Sources, in press.Google Scholar
- X. Yu, J.B. Bates, G.E. Jellison and F.X. Hart, J. Electrochem. Soc.144, 524 (1997).Google Scholar
- A.F. Wells, Structural Inorganic Chemistry, 5th Edition, Clarendon Press, Oxford, 1984.Google Scholar
- R.W.G. Wyckoff, Crystal Structures: Inorganic Compounds Rx(MX4)y, Rx(MnXp)y, Hydrates and Ammoniates, vol. 3, 2nd Edition, Interscience Publishers, New York, 1960.Google Scholar
- R.D. Armstrong and M. Todd in ref. 2.. pp 264–291.Google Scholar
- R.D. Shannon, Acta, Cryst.A32, 751 (1976).Google Scholar
- B.J. Neudecker and W. Weppner, J. Electrochem. Soc.143, 2198 (1996).Google Scholar
- W. Weppner in Solid State Microbatteries, (J.R. Akridge and M. Balkanski, Eds), Plenum Press, New York 1990, p. 381.Google Scholar
- Y-W. Hu, I.D. Raistrick and R.A. Huggins, J. Electrochem. Soc.124, 1240 (1977).Google Scholar
- C. Wagner, in: Proceedings of the 7th meeting of the International Committee on Thermodynamic and Kinetic Electrochemistry (CITCE), Lindau, Germany, Butterworths Publication, London, 1957, p. 361.Google Scholar
- V. Thangadurai and W. Weppner, unpublished results.Google Scholar
- J. Schwenzel, V. Thangadurai and W. Weppner, J. Powder Sources, submitted.Google Scholar
- J. Schwenzel, V. Thangadurai and W. Weppner, in: New Trends in Intercalation Compounds for Energy Storage and Conversion (K. Zaghib, C.M. Julien and J. Prakash, Eds.), ECS proceedings, PV2003-20, 2003, pp. 573–583.Google Scholar