Elton J. Cairns: Recent Research

Elton J. Cairns: Recent Research

Advanced Electrode Research

We have been studying the behavior of electrodes used in advanced secondary batteries and fuel cells currently under development for energy storage applications such as electric vehicles. We have also continued to investigate practical means for improving the performance and lifetimes of these batteries and fuel cells. Systems of current interest include nonaqueous-electrolyte cells with Li electrodes (Li/polymer, Li-ion); and fuel cells that utilize the direct electrooxidation of methanol. We study life-limiting and performance-limiting phenomena under realistic cell operating conditions.

Novel Lithium/Polymer-Electrolyte/Sulfur Cells 

An electrochemical cell based on the lithium/sulfur couple is attractive as an electric vehicle (EV) power source because of its very high theoretical specific energy (2600 Wh/kg). A primary obstacle in producing a functional Li/S cell is the poor conductivity of sulfur. This difficulty led other researchers to utilize sulfur compounds instead of elemental sulfur, a choice which results in significantly lower theoretical specific energies. We are developing ambient-temperature solid-state Li/S cells using solid polymer electrolytes. The use of a solid polymer electrolyte which is ionically conductive below the melting point of sulfur alleviates some problems encountered by researchers studying high-temperature lithium-sulfur cells (e.g. Li/FeS2 cells). It also mitigates problems associated with the use of solid lithium metal in liquid electrolytes.

Sulfur electrodes were initially prepared from suspensions of elemental sulfur powder, carbon (graphite), polyethylene oxide (PEO), lithium trifluoromethanesulfonate (LiTf), and Brij 35 surfactant in acetonitrile. These suspensions were cast onto Teflon-coated plates to produce 100-200 mm thick films. Galvanostatic cycling of cells fabricated from these electrodes and PEO-LiTf electrolyte films showed good charge-discharge behavior at low currents (~10 microA/cm2), but resulted in poor utilization of the active material (of order 1-2%). Scanning electron microscopy (SEM) in conjunction with electron spectroscopy for chemical analysis (ESCA) revealed the presence of 10-micron sulfur islands in the as-prepared sulfur electrodes. Based on our electrochemical and morphological studies, we have formulated a preliminary phenomenological model of the sulfur electrode. The model postulates the creation of a Li2S reaction zone which is characterized by slightly higher ionic conductivity but equally poor electronic conductivity, compared to elemental sulfur. In addition, the volume changes thataccompany the electrochemical reaction are incorporated into the model, which predicts a loss of available active material. This model makes apparent the need for the use of smaller sulfur particles in the electrode, and various fabrication methods were used to achieve this.

Further work on this system has resulted in the achievement of sulfur utilizations of nearly 100% at temperatures near 80C, and long cycle lives in excess of 600 charge-discahrge cycles at 25C. 

XAS Studies of Electrode Materials for Lithium Cells

We seek to establish how Li+ intercalation affects the atomic and electronic structure of Li-Mn-O spinels used in Li secondary batteries. We use a variety of XAS and electrochemical techniques with the intent of developing a solid-state reaction mechanism based upon the aforementioned types of structural change. This information will be used to identify beneficial material parameters providing increased capacity, improved cyclability, and/or higher rate capacities.

MnO2 spinel-based electrodes are the most promising for Li+-intercalation batteries when considering a combination of specific energy, cost, availability, toxicity, and electrode potential. However, batteries derived from these materials display reaction-rate limitations (which affect the battery specific power) and capacity fading that circumvent their present usefulness and commercial viability.

Upon Li+ intercalation, the Mn sites in MnO2-spinel based host materials are reduced from Mn(IV) to Mn(III), and the structure changes to accommodate the Li intercalate at empty tetrahedral or octahedral sites. Therefore, changes in the atomic structure as well as the Mn 3d states occur during the reaction. Previous research on MnO2-spinel based electrodes materials combined electrochemical characterization with structural information obtained from X-ray and/or neutron diffraction studies. Investigators found that, upon discharging, when the average Mn-oxidation state is reduced below 3.5 (x > 1.0 in LixMn2O4), a cooperative Jahn-Teller distortion takes place, and lowers the spinel's symmetry from cubic to tetragonal symmetry and expands the unit cell volume by 5-6%. Measruements of the open-circuit voltage as a function of Li+ content in LixMn2O4 for 0

We use electrochemical characterization techniques to help interpret XAS spectra. The electrochemical techniques are cyclic voltammetry, repetitive galvanostatic cycling, and potential-step voltammetry. The XAS techniques employed in collaboration with Prof. S. Cramer of UC Davis can be grouped into three main categories: 1) X-ray Absorption Near Edge Spectroscopy (XANES), 2) Extended X-ray Absorption Fine Structure (EXAFS), and 3) Kb Emission Spectroscopy. K-edge XANES and EXAFS give information on the local atomic structure about the absorbing atom, which can also be used to interpret the electronic configuration of the absorber. The absorbing atom's electronic structure is directly determinable by Kb Emission Spectroscopy and L2,3-edge XANES as these techniques detect transitions involving the absorbing element's valence states.

We have characterized the base material LiMn2O4. Physical & chemical characterization of this material included atomic absorption, B.E.T. surface area, XRD, and SEM. Electrochemical characterization was carried out in swagelok-type cells within a He glove box and included galvanostatic cycling, cyclic voltammetry, and potential step voltammetry. Additionally, a series of XAS measurements was performed on electrochemically intercalated compositions LixMn2O4, 0

Doped spinels and related structures of the Li-Mn-O system have been synthesized, Li+ intercalated within electrochemical cells, and analyzed by the above described XAS techniques. Atomic and electronic structural changes can then be correlated with electrochemical performance via the techniques described above to identify how the modified spinels behave compared to LiMn2O4. Based on this information, spinels with alternate dopant concentration or type can be synthesized to obtain the parameters for optimum cell performance.

We expect to obtain an atomic-level understanding of how the Mn 3d orbitals adapt to Li+ intercalation in various MnO2-spinel materials, and to establish relationships between the electrochemical information, the L2,3-edge, and K-edge XAS results. This information should allow us to deduce the important compositional and structural properties necessary for the most complete and reversible reactions of lithium with MnO2-spinel and related materials and point the way towards synthesizing improved battery materials.

NMR Studies of Electrode Materials for Li Cells

In collaboration with Prof. J. A. Reimer, we have studied the electronic and atomic structures of a variety of electrode materials for use in rechargeable Li cells. This work has focussed on the understanding of the relationships among structure, performance and stability. 7Li magic angle spinning NMR has proven itself to be an extremely useful tool in understanding the basic structure of electrode materials, and the changes in structure that accompany changes in state of charge and cycling history. This technique has proven itself to be a sensitive indicator of long-term instabilities and incipient failure. Some of the materials studied include LiMn2O4, doped compositions of this material, tunnel, and layered structures on LiMnO2, and doped compositions of this material, and LiFePO4, and variants of this material

Electrocatalysts for Direct-Methanol Fuel Cells

Fuel cells are energy conversion devices that offer the promise of higher efficiencies and greatly reduced emissions, compared to internal combustion engines. Consequently, an application of major interest for these devices is the electric vehicle (EV). However, present-day fuel cells typically operate on H2, so either a H2-storage device or a fuel reformer must be carried onboard the vehicle. Each of these H2-delivery options results in a heavy, bulky, and costly power plant. Therefore there exists a strong need for a fuel cell that can electrochemically oxidize liquid fuels, and the successful development of a direct-methanol fuel cell (DMFC) would represent a major advance.

For vehicle applications, only the polymer and alkaline electrolyte fuel cells are considered to be practical because of their low operating temperatures, i.e. they are capable of rapid start-up because they operate below 150C. The polymer electrolyte fuel cell is an attractive candidate for EV applications, however permeation of CH3OH through the electrolyte significantly degrades its fuel efficiency and performance. The formation of undesirable reaction products and cathode deactivation also reduce the overall performance of fuel cells with acidic electrolytes. The desired reaction products from the electrochemical oxidation of CH3OH are H2O and CO2. Our recent results demonstrated that the direct electrochemical oxidation of CH3OH on supported Pt/Ru alloy electrocatalyst occurs with a polarization comparable to Pt supported on carbon, but at a lower temperature.

We plan to improve DMFC performance by optimizing the overall design and varying the composition of the electrodes and the electrolyte. Recently, we have developed a new electrocatalyst synthesis procedure that allows us to prepare Pt alloy compositions not accessible by other methods in high-area form suitable for use in fuel cell electrodes. New electrocatalyst compositions are being prepared for study in direct methanol fuel cells, and in our NMR cell as described below. 

References

Rauhe BR Jr, McLarnon FR, Cairns EJ. Direct anodic oxidation of methanol on supported platinum/ ruthenium catalyst in aqueous cesium carbonate. J. Electrochem. Soc. 1995; 142:1073.

Striebel KA, McLarnon FR, Cairns EJ. Steady-state model for an oxygen fuel cell electrode with an aqueous carbonate electrolyte. Ind. & Engin.Chem. Res.  1995; 34: 3632.

In Situ Study of Species on Fuel Cell Electrocatalyst Surfaces: NMR Spectroscopic Studies

Platinum is the most active single-component catalyst for methanol electrooxidation in DMFCs, however poisoning reactions on the surface in acidic electrolytes render the anode ineffective under target operating conditions. As an approach to designing better catalysts for this system, a number of in situ, ex situ and on-line techniques have been utilized to obtain information on the nature of the poisoning intermediate(s). While significant advances have been made, no current in situ technique can yield detailed quantitative information on practical (i.e. supported, dispersed) electrocatalysts. Nuclear magnetic resonance (NMR) spectroscopy is a quantitative, non-destructive method of probing the chemical environment of a specific nucleus. During the last two decades the technique has been used successfully in the field of gas-phase catalysis as a tool for identifying and characterizing chemisorbed species on practical catalysts. Our research in collaboration with Prof. Jeffrey A. Reimer has successfully extended the application of NMR spectroscopy to studies of surface poisoning of carbon-supported platinum and platinum-alloy DMFC anodes in operating electrochemical cells. 

We have constructed a glass three-electrode electrochemical cell for use in a narrow-bore (5 cm) spectrometer operating at a proton frequency of 270 MHz. The working electrode material is commercially prepared 20% Pt/Vulcan XC-72 supported on thin carbon cloth. This cloth is rolled tightly to form a cylindrical porous plug, filling the volume of the NMR coil with an active catalyst surface area on the order of 3m2. The electromagnetic coupling of the conductive electrode material with the coil presents a special problem for these experiments. To minimize this effect, a porous separator is wound with the cloth to electronically insulate adjacent layers of the plug.

We have carried out studies of the model system of CO adsorbed on Pt. CO is an important electrocatalyst poison present in reformed methanol and hydrocarbon fuels used in fuel cells. We used a circulation system for adsorption of 13C-enriched CO from saturated aqueous H2SO4. As an indirect monitor we used voltammetry to observe the displacement of adsorbed H2 from the Pt surface by the irreversibly adsorbed CO. We have studied the 13C NMR signal arising from 13CO adsorbed on the electrodes described above open-circuit conditions, and at a variety of controlled potentials. We have been successful in identifying three different surface species resulting from the adsorption of CO on Pt/C, Pt-Ru/C, and Pt-Sn/C at 25C. We are extending these studies to higher temperatures and other electrocatalysts, using CO and CH3OH as the adsorbates.

Application of Pulsed Laser Deposition to the Study of Rechargeable Battery Materials

The aim of this project is to study performance-limiting phenomena in complex metal oxides, present in a wide variety of rechargeable batteries, and to suggest practical means for improving their performance and lifetime in secondary consumer batteries. We prepare thin dense films from these oxides on electronically conductive substrates utilizing the pulsed laser deposition technique. This method is superior to other film-formation techniques, such as sputtering and vapor evaporation, based on both speed and simplicity. Films are characterized with x-ray diffraction, x-ray absorbance, XPS, optical and scanning electron microscopy and profilometry. In addition the groundwork has been laid for the characterization of films with Fourier Transform Infrared Spectroscopy (FTIR).

Transmission-mode FTIR spectra were obtained from LixMn2O4 cathodes, where x was varied electrochemically from "zero" to 2.4. The observed infrared absorption peaks can be assigned to the various Mn-O and Li-O environments within the spinel framework. The results correlate well with XRD and neutron diffraction analyses in the literature as well as with the phase behavior indicated by electrochemical measurements. The technique gives both qualitative and quantitative information and is shown to be an effective companion technique to x-ray diffraction. The mechanisms responsible for capacity fading during normal cycling of LiMn2O4 cells in both the 3 V and 4 V regions were determined by examination of spectra obtained from electrodes following 25 cycles at charge and discharge rates of C/6. In the 3 V region, electroactive material becomes electronically disconnected from the rest of the electrode possibly due to fracture of the oxide particles during the cubic-to-tetragonal phase transformation. In the 4 V region, the active electrode material is gradually converted to a lower-voltage defect spinel phase via dissolution of manganese in the electrolyte.

Electrochemical properties of the metal oxide films, such as electrocatalyst kinetics, film corrosion behavior and active species diffusivity, can be measured by employing standard techniques for geometries with well-defined electrode-electrolyte interfaces. The pulsed laser deposition technique has been used to prepare smooth dense films La0.6Ca0.4CoO3 , La0.6Ca0.4MnO3, La0.5Sr0.5FeO3, Bi2Ru2O7, LixMn2O4 and LixCoO2 on substrates of stainless steel, quartz and silicon. High-quality crystalline films of all of the oxides except Bi2Ru2O7 were obtained by deposition onto stainless steel at 600°C in the presence of 100 mtorr of O2. The correct structure for the Bi2Ru2O7 films was obtained by lowering the O2 pressure while maintaining the total pressure with Ar.

The rates of O2 reduction and evolution on thin films of La0.6Ca0.4CoO3, La0.6Ca0.4MnO3 and La0.5Sr0.5FeO3, were measured with the RRDE technique in 0.1M KOH. The order of activity was La0.6Ca0.4MnO3 > La0.5Sr0.5FeO3 > La0.6Ca0.4CoO3 with Tafel slopes of ~90 mV/decade. The order of activity for O2 evolution was La0.6Ca0.4MnO3 > La0.6Ca0.4CoO3 > La0.5Sr0.5FeO3 with Tafel slopes of ~60 mV/decade. A partially carbon-coated La0.6Ca0.4CoO3 film showed higher currents for O2 reduction than the bare film, due to O2 reduction on the carbon and further reaction on the neighboring La0.6Ca0.4CoO3. We believe that this is the first direct measurement of the synergism between O2 reduction of the oxide and the carbon.

Films of LixMn2O4 and LixCoO2 from 0.125 to 1.5 mm thick have been subjected to a wide range of electrochemical studies. Film capacity densities as high 56 and 62 mAh/cm2-mm were measured for LixMn2O4 and LixCoO2, respectively. LixMn2O4 films have been subjected to >350 cycles at 10 mA/cm2 with insignificant fading of capacity. Capacity losses on increasing charge and discharge current density to 100 mA/cm2 were ~54%. These studies are not yet complete but they illustrate the promise of pulsed laser deposition for the production of cathode films for rechargeable lithium microbatteries.

The chemical diffusivities of lithium in LixMn2O4 were measured with the current step/relaxation technique with both thin-film and porous PTFE-bonded electrodes of LixMn2O4. Diffusion coefficients of 1-3 x10-11 cm2/sec were measured in both electrodes if the critical distance in the porous electrode is assumed to be the grain size of the oxide as determined with X-ray diffraction, as opposed to the thickness of the electrode.

Future work will involve preparation and characterization of doped LixMn2O4 films and films of anode materials for Li cells. Extension of the FTIR techniques developed so far to investigations of thin-film electrodes should yield further insight into capacity-fade mechanisms.

References

Striebel KA, Deng CZ and Cairns EJ. Pulsed laser deposition of transition-metal oxides for secondary batteries. Materials Research Society Symposium Proceedings Series, Vol. 393, Spring Meeting, 1995. 

Striebel KA, Deng CZ and Cairns EJ. Oxygen reduction on La0.6Ca0.4CoO3 and La0.6Ca0.4MnO3 thin films in alkaline electrolytes.Electrochemical  Society Symposium Proceedings, March 1996.

Striebel KA, Deng CZ and Cairns EJ. Electrochemical behavior of LiMn2O4 and LiCoO2 thin films produced with pulsed laser deposition. Submitted to J. Electrochem. Soc., August 1995.

Wen SJ, Richardson TJ, Ma L, Striebel KA, Ross PN and Cairns EJ. FTIR spectroscopy of metal oxide insertion electrodes: capacity fading in secondary Li/LiMn2O4 cells. Submitted to J. Electrochem. Soc., Nov. 1995.

Wen SJ, Richardson TJ, Ma L, Ghantous DI, Striebel, KA, Ross PN and Cairns EJ. Application of FTIR spectroscopy to the study of LixMn2O4 for rechargeable lithium batteries. Submitted to J. Electrochem. Soc., December 1995.

Anion Adsorption at Electrocatalyst Surfaces: Probe Beam Deflection Study

The rate and extent of anion adsorption on electrocatalyst surfaces can have a major effect on the electrochemical kinetics of important fuel cell reactions such as hydrogen oxidation, methanol oxidation and oxygen reduction. Anion adsorption isotherms are generally difficult to measure, and little reliable data have been reported in the literature. The purpose of this work is to use the in situ Probe Beam Deflection (PBD) technique to study the rate and extent of anion adsorption at polycrystalline Pt electrode surfaces as a function of electrode potential. We have carried out a series of PBD experiments to detect the proton and anion fluxes that accompany the oxidation and reduction processes that proceed on Pt electrode surfaces in 0.1 M solutions of H3PO4, H2SO4 and HClO4. The measured beam-deflection signals exhibited a strong dependence on electrode potential and anion identity. We found that in all three electrolytes the onset of anion adsorption began at ~200 mV (vs the dynamic hydrogen reference electrode), i.e. within the potential range wherein adsorbed H2 is oxidized. We also confirmed that the presence of PO43- anions shifts the Pt oxidation reaction towards more positive potentials.

References

Brisard GM, Rudnicki JD, McLarnon FR, Cairns EJ. Application of probe beam deflection to study the electrooxidation of copper in alkaline media. Electrochim. Acta 1995; 40:859.

Deng Z, Spear JD, Rudnicki JD, McLarnon FR, Cairns EJ. Infrared-photothermal deflection spectroscopy: a new probe for the investigation of electrochemical interfaces. Paper no. 669 presented at the 187th Meeting of the Electrochemical Society, Reno, NV, May 1995.

Selected Recent Publications

Kentaro Nakahara, Shigeyuki Iwasa, Jiro Iriyama, Yukiko Morioka, Masahiro Suguro, Masaharu Satoh, and Elton J. Cairns,  “Electrochemical and spectroscopic measurements for stable nitroxyl radicals”, Electrochimica Acta 52, 921–927 (2006)

Kentaro Nakahara, Jiro Iriyama, Shigeyuki Iwasa, Masahiro Suguro, Masaharu Satoh, Elton J. Cairns, Al-laminated film packaged organic radical battery for high-power applications, Journal of Power Sources 163, 1110–1113 (2007)

Aniruddha Deb and Elton J. Cairns, "In situ X-ray absorption spectroscopy—A probe of cathode materials for Li-ion cells" Fluid Phase Equilibria 241, 4–19 (2006)

Kenneth W. Lux and Elton J. Cairns, "Lanthanide-Platinum Intermetallic Compounds as Anode Electrocatalysts for Direct Ethanol PEM Fuel Cells II. Performance of LnPt2 (Ln = Ce, Pr) Nanopowders in an Operating PEM Fuel Cell", Journal of The Electrochemical Society, 153, 6, A1139-A1147  (2006)

Kenneth W. Lux and Elton J. Cairns, "Lanthanide-Platinum Intermetallic Compounds as Anode Electrocatalysts for Direct Ethanol PEM FuelCells I. Synthesis and Characterization of LnPt2 (Ln = Ce, Pr) Nanopowders", Journal of The Electrochemical Society, 153, 6, A1132-A1138  (2006)

Aniruddha Deb, Uwe Bergmann, James M. Ralph, and Elton J. Cairns, "Combined temperature-dependent XANES and EXAFS studies of La0.8Sr0.2FeO3 and La0.7Sr0.2FeO3-d " Physical Review B 73 115114 (2006)

Aniruddha Deb. Uwe Bergmann, Stephen P. Cramer, and Elton J. Cairns, "Local structure of LiNi0.5Mn0.5O2 cathode material probed by in-situ X-ray Absorption Spectroscopy" J. Appl Phys, 99, 063701 (2006)

J.T. Son and E.J. Cairns "Preparation and Characterization of Li1.05Ni0.35Co0.25Mn0.4O2 As a New Cathode Material for Lithium Cells" Electrochemical and Solid-State Letters9, 1, A27-A30  (2006). 

Sam L. Wilcke, Elton J. Cairns, Jeffrey A. Reimer "An effective stochastic excitation strategy for finding elusive NMR signals from solids" Solid State Nuclear Magnetic Resonance 29, 199–203  (2006) 

Marie Kerlau, Jeffrey A. Reimer, and Elton J. Cairns, "Investigation of Particle Isolation in Li-ion Battery Electrodes by using  7Li NMR Spectroscopy" Electrochemistry Communications 7, 1249–1251 (2005)

Aniruddha Deb, Uwe Bergmann, S. P. Cramer, Elton J. Cairns "Structural Investigations of LiFePO4 electrodes and in-situ Studies by Fe X-ray Absorption Spectroscopy", Electrochimica Acta 50, 5200–5207 (2005)

Marie Kerlau, Jeffrey A. Reimer, and Elton J. Cairns, "Layered Nickel Oxide-Based Cathodes for Lithium Cells: Analysis of Performance Loss Mechanisms" JECS, 152, A1629 (2005)

Aniruddha Deb, Uwe Bergmann, Stephen P. Cramer, and Elton J. Cairns  "In situ X-ray Absorption Spectroscopic Study of the Li[Ni1/3Co1/3Mn1/3]O2 Cathode Material", J. Appl. Phys., 97, 113523 (2005)

H. S. Ryu, H. J. Ahn, K.W. Kim, J. H. Ahn, J.Y. Lee, E.J. Cairns, "The self-discharge of lithium/sulfur cells using stainless steel current collectors", Journal of Power Sources 140, 365–369  (2005)

O. Haas, A. Deb, E.J. Cairns,  A. Wokaun, "Synchrotron X-ray Absorption Study of LiFePO4 Electrodes", J. Electrochem Soc. 152, A191 (2005)

Committee on Soldier Power/Energy Sources (E.J. Cairns, co-author) “Meeting the Energy Needs of Future Warriors. Board on Army Science and Technology”, Division on Engineering and Physical Sciences, 136 pp.  National Academies Press, Wash. DC, 2004. ISBN 0-309-092620

AniruddhaDeb,UweBergmann,Elton J. Cairns and S. P. Cramer, "X-ray absorption spectroscopy study of the LixFePO4 cathode during cycling using a novel electrochemical in-situ reaction cell", J. Synch. Rad., 11, 1-8 (2004)

Aniruddha Deb, Uwe Bergmann, Marca M. Doeff, Elton J. Cairns, and Stephen P. Cramer “Structural Investigations of LiFePO4 Electrodes by Fe X-ray Absorption Spectroscopy”, J. Phys Chem B, 108(22); 7046-7051. (2004).

Seung-Wan Song, Ronald P. Reade, Elton J. Cairns, Jack T. Vaughey, Michael M. Thackeray and Kathryn A. Striebel “Cu2Sb Thin Film Electrodes Prepared by Pulsed Laser Deposition” J. Electrochem. Soc., 151, A1012-A1019 (2004)

K. A. Striebel, J. Shim, E. J. Cairns, R. Kostecki, Y.-J. Lee, J. Reimer, T. J. Richardson, P. N. Ross, X. Song, and G. V. Zhuang, "Diagnostic Analysis of Electrodes from High-Power Lithium-Ion Cells Cycled under Different Conditions", J. Electrochem. Soc. 151, A857 (2004)

215. Elton J. Cairns, “Batteries Overview” in Encyclopedia of Energy, Cutler J. Cleveland, ed., Elsevier, Oxford, 2004. 

G.A. Roberts, E.J. Cairns, J.A. Reimer, and K.J. Gross, “ The Mechanism of Lithium Insertion into Magnesium Silicide”, J. Electrochem. Soc., 151, A493 (2004)

Tom A. Eriksson, Young Joo Lee, Joel Hollingsworth, Jeffrey A. Reimer, Elton J. Cairns, Xiao-feng Zhang, and Marca M. Doeff, ”Influence of Substitution on the Structure and Electrochemistry of Layered Manganese Oxides”, Chem. Mat., 15 (23); 4456-4463 (2003)

Marca M. Doeff, Joel Hollingsworth, Joongpyo Shim, Young Joo Lee, Kathryn Striebel, Jeffrey A. Reimer, and Elton J. Cairns, “Sulfur-Doped Aluminum-Substituted Manganese Oxide Spinels for Lithium-Ion Battery Applications” J Electrochem. Soc., 150, A1060 (2003).

Gerd Sandstede, Elton J. Cairns, Vladimir S. Bagotsky and Klaus Wiesener, “General scientific background before and during the beginning of fuel cell research” in Handbook of Fuel Cells – Fundamentals, Technology and Applications Volume 1, Part 4, pp 143-219, Edited by Wolf Vielstich Arnold Lamm and Hubert A. Gasteiger, John Wiley & Sons, Ltd, Chichester, 2003

Seung-Wan Song, Kathryn A. Striebel, Xiangyun Song and Elton J. Cairns “Amorphous and Nanocrystalline Mg2Si Thin Film Electrodes”, J. Power Sources (IMLB-11) 119-121, 110 (2003)

G. A. Roberts, E. J. Cairns, and J. A. Reimer “An Electrochemical and XRD Study of Lithium Insertion into Mechanically Alloyed Magnesium Stannide” Journal of The Electrochemical Society, 150, A912 (2003)

A. Braun, S. Shrout, A. C. Fowlks, B. A. Osaisai, S. Seifert, E. Granlund and E. J. Cairns, “Electrochemical in-situ reaction cell for X-ray scattering, diffraction and spectroscopy”. J. Synchrotron Rad10, 320-325, (2003).

E. J. Cairns “Aqueous carbonate electrolyte fuel cells” in Handbook of Fuel Cells – Fundamentals, Technology and Applications Volume 1, Part 4, pp 301–304, Edited by Wolf Vielstich Arnold Lamm and Hubert A. Gasteiger, John Wiley & Sons, Ltd, Chichester, 2003

Seung-Wan Song, Kathryn A. Striebel, Ronald P. Reade, Gregory A. Roberts, and Elton J. Cairns, “Electrochemical Studies of Nanocrystalline Mg2Si Thin Film Electrodes Prepared by Pulsed Laser Deposition”, J. Electrochem. Soc., 150, A121 (2003)

A. Braun, U. Bergmann, Wang, Gu, S.P. Cramer, M.C. Tucker, and E.J. Cairns, "Origin of chemical shift of manganese in lithium battery electrode materials - A comparison of hard and soft - x-ray techniques" Journal of Power Sources 112, 231-235 (2003)

Kyoo-Seung Han, Seung-Wan Song, Hirofumi Fujita, and Masahiro Yoshimura, Elton J. Cairns, and Soon-Ho Chang, "Direct Electroplating of Lithium Cobalt Oxide Film on Platinum Substrate in 100°&endash;200°C Aqueous Solution" J. Am. Ceram. Soc., 85 [10] 2444&endash;48 (2002).

M.C. Tucker, L. Kroeck, J.A. Reimer, and E.J. Cairns, "The Influence of Covalence on Capacity Retention in Metal-Substituted Spinels: 7Li NMR, SQUID, and Electrochemical Studies", Journal of the Electrochemical Society, 149, A1409 (2002)

G. A. Roberts, E. J. Cairns, and J. A. Reimer, "Magnesium Silicide as a negative Electrode Material for Lithium-Ion Batteries", J Power Sources, 110, (2), 424-429, (2002).

Joongpyo Shim, Kathryn A. Striebel, and Elton J. Cairns, "The Lithium/Sulfur Rechargeable Cell: Effects of Electrode Composition and Solvent on Cell Performance", J. Electrochem. Soc., 149, A1321 (2002)

Michael C. Tucker, Jeffrey A. Reimer, Elton J. Cairns, S. Choi and A. Manthiram, "7Li NMR Studies of Chemically-Delithiated Li1-xCoO2" , J. Phys Chem.B, 106, 3842 (2002)

M. C. Tucker, M. M. Doeff, T. J. Richardson, R. Fiñones, E. J. Cairns, and J. A. Reimer, "Hyperfine Fields at the Li Site in LiFePO4-Type Olivine Materials for Lithium Rechargeable Batteries: A 7Li MAS NMR and SQUID Study" Journal of the American Chemical Society, 124, 3832 (2002).

M. C. Tucker, J. A. Reimer, E. J. Cairns, "A 7Li NMR Study of Capacity Fade in Metal-Substituted Lithium Manganese Oxide Spinels", Journal of the Electrochemical Society, 149,A574 (2002).

Michael C. Tucker, Marca M. Doeff, Thomas J. Richardson, Rita Fiñones, Jeffrey A. Reimer, and Elton J. Cairns, "7Li and 31P MAS NMR of LiFePO4-Type Materials", Electrochem. Soc. Letters, 5, A95 (2002)

K.A. Striebel, E. Sakai, and E.J. Cairns, "Impedance Studies of the Thin Film LiMn2O4 / Electrolyte Interface", J. Electrochem Soc., 149, A61 (2002)

Joongpyo Shim, Chang-Rae Lee, Hong-Ki Lee, Ju-Seong Lee and Elton J. Cairns, "Electrochemical characteristics of Pt-WO3/C and Pt-TiO2/C electrocatalysis in a polymer electrolyte fuel cell", J. Power Sources, 102, 172 (2001)

Michael C. Tucker, Jeffrey A. Reimer, and Elton J. Cairns, "A 7Li NMR Study of Metal-Substituted Lithium Manganese Oxide Spinels", J. Electrochem Soc., 148, A951 (2001)

X. Zhanga, P. N. Ross, Jr. a, R. Kostecki, F. Kong, S. Sloop, J. B. Kerr,K. Striebel, E. Cairns, F. McLarnonz , "Diagnostic Characterization of High-Power Lithium-Ion Batteries for Use in Hybrid Electric Vehicles", Journal of the Electrochemical Society, 148, A463 (2001)

A. Braun, S. Seifert, P. Thiyagarajan, S.P. Cramer, E.J. Cairns, "In-situ anomalous small angle X-ray scattering and absorption on an operating rechargeable lithium ion battery" Electrochemistry Communications, 3, 136 (2001) 

Benjamin M. Rush, Jeffrey A. Reimer, and Elton J. Cairns, "Nuclear Magnetic Resonance and Voltammetry Studies of Carbon Monoxide Adsorption and Oxidation on a Carbon-Supported Platinum Fuel Cell Electrocatalyst", Journal of the Electrochemical Society, 148, A137 (2001

Craig R. Horne, Uwe Bergmann, Melissa M. Grush, Rupert C. C. Perera, David L. Ederer, Thomas A. Calcott, Elton J. Cairns, and Stephen P. Cramer, "Electronic Structure of Chemically-Prepared LixMn2O4 Determined by Mn X-ray Absorption and Emission Spectroscopies", J. Phys Chem B., 104, 9587-9596 (2000).

Michael C. Tucker, Jeffrey A. Reimer, and Elton J. Cairns, "A 7Li NMR Study of Lithium Insertion into Lithium Manganese Oxide Spinel", Electrochemical and Solid State Letters, 3, (10) 463-466, 2000

D. Marmorstein, T.H. Yu, K.A. Striebel, F.R. McLarnon, J. Hou, and E. J. Cairns, "Electrochemical Performance of Lithium/Sulfur Cells with Three Different Polymer Electrolytes", J. Power Sources, 89, 219 (2000).

C.R. Horne, U. Bergmann, J. Kim, K.A. Striebel, A. Manthiram, S.P. Cramer, E.J. Cairns, "Structural investigations of Li1.5+xNa0.5MnO2.85I0.12 Electrodes by Mn X-ray Absorption Near Edge Spectroscopy", Journal of the Electrochemical Society, 147, 395 (2000)., LBNL-42811

Ederio D. Bidoia, Frank R. McLarnon, and Elton J. Cairns, "Investigation of Anion Adsorption on Platinum Electrodes in Aqueous Media by Probe Beam Deflection", J. Electroanal. Chem., 482, 75 (2000)

M. M. Grush, C.R. Horne, R.C.C. Perera, D. L. Ederer, S.P. Cramer, E. J. Cairns, and T.A. Talcott, "Correlating Electronic Structure with Cycling Performance of Substituted LiMn2O4 Electrode Materials - A Study Using the Techniques of Soft X-ray Absorption and Emission, Chem. Mat., 12, 659 (2000).

K.A.Striebel, A. Rougier, C. R. Horne, R. P. Reade, and E. J. Cairns, "Electrochemical Studies of Substituted Spinel Thin Films", J. Electrochem. Soc., 146,4339 (1999).

A. Rougier, K.A. Striebel, S.J. Wen, and E.J. Cairns, "Cyclic Voltammetry of Pulsed Laser Deposited LixMn2O4 Thin Films", J. Electrochem. Soc., 145, 2975 (1998).

A. Rougier, K.A. Striebel, S.J. Wen, T.J. Richardson, R.P. Reade, and E.J. Cairns, "Characterization of Pulsed Laser Deposited LiMn2O4 Thin Films for Rechargeable Lithium Batteries", Applied Surface Science, 134, 107-115 (1998).

T. C. Adler, F. R. McLarnon, and E. J. Cairns, "Investigations of a New Family of Alkaline-Fluoride-Carbonate Electrolytes for Zinc/Nickel Oxide Cells", Ind. Eng. Chem., 37, 3237-3241 (1998).

Becky Gee, Craig R. Horne, Elton J. Cairns, and Jeffrey A Reimer, "Supertransferred Hyperfine Fields at 7Li: Variable Temperature 7Li NMR Studies of LiMn2O4-Based Spinels", J. Phys. Chem. B, 102, 10142 (1998).

T. J. Richardson, S. J. Wen, K. A. Striebel, P. N. Ross, Jr., and E. J. Cairns "FTIR Spectroscopy of Metal Oxide Insertion Materials: Analysis of LixMn2O4 Spinel Electrodes",Materials Research Bulletin, 32, 609 (1997).

K. A. Striebel, S. J. Wen, D. I. Ghantous, and E. J. Cairns, "Novel Nanodisperse Composite Cathode for Rechargeable Lithium/Polymer Batteries", J. Electrochem. Soc., 144, 1680 (1997).

E.J Cairns, C. R. Horne, B. J. R. Weiss, M. M. Grush, and S. P. Cramer, "X-Ray Absorption Spectroscopic Investigations of LixMn2O4", Proc. 2nd Internat. Symp. on New Mat'ls for Fuel Cells and Modern Battery Systems, 1997.

M. L. Perry, J. Newman, and E. J. Cairns, "Mass Transport in Gas-Diffusion Electrodes: A Diagnostic Tool for Fuel-Cell Cathodes" J. Electrochem. Soc.,145,5 (1998).

C-K Lee, K. Striebel, F. McLarnon, and E. J. Cairns, "Thermal Treatment of La0.6Ca0.4CoO3 Perovskite Oxides for Bifunctional Air Electrodes", J. Electrochem. Soc, 144, 3801, (1997).

S.J. Wen, T.J Richardson, L. Ma, K.A. Striebel, P.N. Ross, E.J. Cairns, "FTIR Spectroscopy of Metal Oxide Insertion Electrodes: Capacity Fading in Secondary Li/LiMn2O4 Cells", J. Electrochem. Soc., 143, No. 5, pp. L136-L138, (1996).

K.A. Striebel, C.Z. Deng, S.J. Wen and E.J. Cairns, "Electrochemical Behavior of LiMn2O4 and LiCoO2 Thin Films Produced with Pulsed Laser Deposition", J. Electrochem. Soc. 143, No. 6, pp. 1821-1827, (1996).

K.A. Striebel, C.Z. Deng, S.J. Wen and E.J. Cairns, "Oxygen Reduction and Evolution on Perovskite Thin Films Made with Pulsed Laser Deposition", proceedings of the Symposium on Oxygen Electrochemistry, Electrochemical Society Meeting, Vol. 95-26, p. 112, (1995).

S.J. Wen, T.J. Richardson, D.J. Ghantous, K.A. Striebel, P.N. Ross and E.J. Cairns, "FTIR Characterization of PEO/LiN(CF3SO2)2 Electrolytes", J. Electroanalytical Chemistry and Interfacial Phenomena 408, 113-118 (1996).

M.S. Yahnke, B.M. Rush, J.A. Reimer, and E.J. Cairns, "Quantitative Solid-State NMR Spectra of CO Adsorbed from Aqueous Solution onto Commercial Electrode Materials" J. Am. Chem. Soc. 118, 12250 (1996).

Z. Deng, J.D. Spear, J.D. Rudnicki, F.R. McLarnon and E.J. Cairns, "Infrared Photothermal Deflection Spectroscopy: A New Probe for the Investigation of Electrochemical Interfaces," J. Electrochem. Soc. 143, 1502 (1996).

B.R. Rauhe, Jr., F.R. McLarnon and E.J. Cairns, "Direct Anodic Oxidation of Methanol on Supported Platinum/Ruthenium Catalyst in Aqueous Cesium Carbonate," J. Electrochem. Soc. 142, 1073-1084 (1995).

G.M. Brisard, J.D. Rudnicki, F. McLarnon and E.J. Cairns, "Application of Probe Beam Deflection to Study the Electrooxidation of Copper in Alkaline Media," Electrochim. Acta 40, 859-865 (1995).

K.A. Striebel, F.R. McLarnon and E.J. Cairns, "Steady-State Model for an Oxygen Fuel Cell Electrode with an Aqueous Carbonate Electrolyte," Ind. & Engin. Chem. Res. 34, 3632-39 (1995).

H.A. Gasteiger, N. Markovic, P.N. Ross Jr. and E.J. Cairns, "CO electrooxidation on well-characterized Pt-Ru alloys," J. Phys. Chem. 98, 617 (1994).

H.A. Gasteiger, N. Markovic, P.N. Ross Jr. and E.J. Cairns, "Electrooxidation of small organic molecules on well-characterized Pt-Ru alloys," Electrochim. Acta 39, 1825 (1994).

H.A. Gasteiger, N. Markovic, P.N. Ross Jr. and E.J. Cairns, "Temperature-dependent methanol electro-oxidation on well-characterized Pt-Ru alloys," J. Electrochem. Soc. 141, 1795 (1994).