Jeff Dahn Professor New Materials for Advanced Batteries   B.Sc., Dalhousie University (1978)  M.Sc., University of British Columbia (1980)  Ph.D., University of British Columbia (1982)  Office Phone: (902) 494-2312 e-mail: jeff.dahn@dal.ca See Also: http://fizz.phys.dal.ca/people/jdahn.html

    Rechargeable batteries play a critical role in today's world of mobile communications and portable electronics. Furthermore, the age of electric vehicles is about to begin, and advanced batteries are necessary. The lithium-ion battery is the state-of-the-art rechargeable power source. It stores about twice the energy per unit mass or volume of conventional technologies and is hence very attractive. Sales of small lithium-ion batteries will be $4 billion dollars in 2000. The fundamental physics and chemistry of the Li-ion battery is based on a process known as "intercalation"; the reversible insertion of guest atoms (like lithium) into host solids (the battery electrode materials).
     Our research focuses on the synthesis and characterization of new intercalation compounds, which can store more guest atoms per formula weight of host. This leads to batteries with even higher energy densities and allows reduction of the size of battery packs.
     Students involved in these studies learn to synthesize new materials using a variety of techniques, including Chemical Vapor Deposition, Sol-Gel methods and direct solid-state reactions. Materials are characterized using X-ray, neutron scattering, electron spectroscopy at synchrotron sources, thermal analysis, gas adsorption porosimetry, and by electrochemical methods in lithium batteries. In addition, in situ methods using electrochemical cells with appropriate "windows" are used to monitor changes to the host compounds as a function of intercalant composition. An Accelerating Rate Calorimeter has just been aquired to study the reactions which occur in lithium-ion cells at high temperatures. Theoretical studies to explain the behaviour of these materials are also routinely made.
     The group has strong collaborations with a variety of groups, including the Lithium Battery group at 3M in Minneapolis. Typically, graduates of this laboratory have found immediate employment in the battery and battery materials industries.

Selected Publications

• Yuan Gao and J.R. Dahn "The high temperature phase diagram of Li_(1+x)Mn_(2-x)O₄ and its implications" J. Electrochem. Soc. 143 (1996) 1783-1788.
• Tao Zheng, J.S. Xue, and J.R. Dahn "Lithium insertion in hydrogen containing carbonaceous materials" Chemistry of Materials 8 (1996) 389-393.
• J.R. Dahn, Tao Zheng, J.S. Xue, and Yinghu Liu "Three mechanisms for lithium insertion in carbonaceous materials" Science 270 (1995) 590-593.
• Tao Zheng, J.N. Reimers, and J.R. Dahn "The effect of turbostratic disorder in graphitic carbons on the intercalation of lithium" Phys. Rev. B. 51 (1995) 734-741.
• A.M. Wilson, J.N. Reimers, E.W. Fuller, and J.R. Dahn "Lithium insertion in carbons containing nano-dispersed silicon" J. Electrochem. Soc. 142 (1995) 326-332.
• W. Li, D.S. Wainwright, and J.R. Dahn "Rechargeable lithium batteries with aqueous electrolytes" Science 264 (1994) 1115-1117.
• W. Li, J.N. Reimers, and J.R. Dahn "A lattice-gas model approach to understanding the structures of lithium transition metal oxides (LiMO₂)" Phys. Rev. B 49 (1994) 826-831.
• W. Li, J.N. Reimers, and J.R. Dahn "In situ x-ray diffraction and electrochemical studies of Li_(1+x)NiO₂" Solid State Ionics 67 (1993) 123-130.
• J.R. Dahn, U. von Sacken, H. Al-Janaby, and M.W. Juzkow "Rechargeable LiNiO₂/carbon cells" J. Electrochem. Soc. 138 (1991) 2207-2212.

Updated 28 November 1997