Bahne C. Cornilsen
- Chem Sci 706A
Professor Emeritus, Chemistry
- PhD, Ceramic Science, New York State College of Ceramics, Alfred University, 1975
- MS, Chemistry, Marquette University, Milwaukee, 1971
- BS, Chemistry, Illinois Institute of Technology, Chicago, 1968
Dr. Cornilsen's research group is investigating structure in the solid state. This structure is of basic scientific and practical import. For example, the properties of semiconductors, heterogenous catalysts, and battery electrodes depend on the molecular or crystallographic structure and bonding as well as the point defect structure. The nonstoichiometry and dopant content controls the latter, which in turn controls the electrical conductivity and proton transport. A nonstoichiometric structural model for the nickel electrode has been developed to describe structural changes occurring during charge and discharge cycling. We are interested in the subtle point defect structure and the lattice structure, including how point defects are accommodated. Basic to these studies is the preparation of high purity materials and precisely doped materials, as well as their careful characterization.
Current research includes in situ laser Raman spectroscopic measurements of battery electrodes during cycling, quantitative mineral analysis, and of sol-gel process kinetics (used to prepare glasses and catalysts). We have pioneered the use of Raman spectroscopy to characterize nonstoichiometry and point defects in oxides, including Ni1-xO, BaTiO3-x, NixOOH and PrOx. Photoacoustic IR spectroscopy is being used to study powder surface properties which influence water adsorption and catalytic properties. X-ray absorption spectroscopy is also being used to study bond distances, oxidation state and coordination number of cations.
The structure of nickel electrode materials, used in Ni-Cd and Ni-H2 batteries is being correlated with electrochemical properties so that the latter can be optimized. Structural changes and phases have been found which were not discernible using other structural techniques, such as x-ray diffraction. Two phases have been identified which lead to battery failure, one of which has been traditionally thought a discharge product.
- The nickel electrode used in Ni-hydrogen and Ni-Cd batteries (the active cathode material is actually a nickel hydroxide or oxyhydroxide)
- Prediction of vibrational spectra
- Influence of point defects on vibrational spectra
- Vibrational spectra of minerals
- "A Nonstoichiometric Structural Model to Characterize Changes in the Nickel Hydroxide Electrode during Cycling," Journal of. Solid State Electrochemistry, 9, 61-76 (2005), V. Srinivasan, B. C. Cornilsen, and J. W. Weidner.
- "Quantitative Mineral Analysis by FTIR Spectroscopy," The Internet Journal of Vibrational Spectroscopy, 5, edn. 4, (2001) (Revised 13 August 2001), Z. Xu, B.C. Cornilsen, D.C. Popko, W.D. Pennington, J.R. Wood, and J-Y. Hwang.
- "Quantitative Determination of Ni(II) & Ni(IV) in Nickel Electrode Active Mass using X-ray Absorption Spectroscopy," Selected Battery Topics (W.R. Cieslak, Sr. Ed.), Proceedings Vol. 98-15, The Electrochemical Society, Pennington, NJ, 1999, p. 1, Z. Xu, B.C. Cornilsen, and G. Meitzner.
- "The Nonstoichiometric, Solid Solution Structural Model for Nickel Electrode Active Mass," Selected Battery Topics (W.R. Cieslak, Sr. Ed.), Proceedings Vol. 98-15, The Electrochemical Society, Pennington, NJ, 1999, p. 23, B.C. Cornilsen.
- "The Application of Point Defect Chemistry in Characterizing the Redox Processes in the Nickel Hydroxide Electrode," Selected Battery Topics (W.R. Cieslak, Sr. Ed.), Proceedings Vol. 98-15, The Electrochemical Society, Pennington, NJ, 1999, p. 31, V. Srinivasan, B.C. Cornilsen and J.W. Weidner.
- "Quantitative Oxidation State Determination of Nickel Oxyhydroxides by X-ray Absorption Spectroscopy," Electrochemistry of Glass and Ceramics, Ceramic Transactions, Vol. 92 (S.K. Sundaram, D.F. Bickford, and E.J. Hornyak, Eds.), American Ceramic Society, Westerville, OH, 1999, pp. 25-36, B.C. Cornilsen, Z. Xu, and G. Meitzner.
- "Microstructural Studies of Chemically and Electrochemically Lithiated Vanadium Pentoxide," Prog. Batteries Battery Mater., Vol. 16, 1997, pp. 59-70, S.A. Hackney, B.C. Cornilsen, C.R. Walk, and N. Margalit.