Prof.
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 < x
< 2 show two voltage plateaus when the Li+ content is varied over the full
range, the 4 volt plateau for 0 < x< 1, and the 3 volt plateau for 1 <
x < 1.8. Introduction of dopants and cation vacancies into LiMn2O4 has yielded improved Li+
intercalation properties. Dopants were shown to be
superior to cation vacancies for improving cell cycling stability. Due to the
nature of XRD and neutron diffraction techniques, these studies have provided a
long-range atomic structural picture as well as an indirect approach to
interpreting electronic structure information.
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 < x < 2.2. The electrochemical intercalation was performed
slowly and the electrodes were allowed to reach open-circuit potentials after
the calculated charge was passed to achieve the desired lithiated
state, x. The XAS measurements included K-edge XANES & EXAFS, Kb emission,
and L2,3-edge absorption. We measured the Mn K-edge
XANES data set. Along the 4 volt plateau, the spectra all correspond to
octahedral symmetry of the oxygen ligands about the Mn. Small distortions of
the Mn local environment occur due to Li+ intercalation and are reflected by
the inflection seen in the edge spectra. The observations are consistent with a
cubic spinel structure. However, along the 3V plateau a step develops in the
absorption edge which is indicative of octahedral distortion caused by the
Jahn-Teller effect and the resultant tetragonal symmetry of the highly lithiated phase. The Mn K-edge main peak result primarily
from 1s ` 4p transitions. As the Jahn-Teller distortion occurs, the oxygen octahedra surrounding the Mn elongate along the z-axis. The
larger Mn-O distance along the z-axis splits the degeneracy of the Mn 4p states
by lowering the energy of the 4pz orbital relative to the 4px and 4py giving
the observed step in the XANES.
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,
Striebel KA, McLarnon FR,
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
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
Striebel KA, Deng CZ and
Striebel KA, Deng CZ and
Wen SJ,
Wen SJ,
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,
Deng Z, Spear JD, Rudnicki JD, McLarnon FR,
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
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.
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.
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.
G.A. Roberts, E.J.
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 Rad. 10, 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.
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.
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.
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.
A. Rougier, K.A. Striebel, S.J. Wen, T.J. Richardson, R.P. Reade, and E.J.
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.
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,
E.J
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.
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.
M.S. Yahnke, B.M. Rush,
J.A. Reimer, and E.J.
Z. Deng, J.D. Spear, J.D. Rudnicki, F.R.
McLarnon and E.J.
B.R. Rauhe,
Jr., F.R. McLarnon and E.J.
G.M. Brisard, J.D.
Rudnicki, F. McLarnon and E.J.
K.A. Striebel, F.R.
McLarnon and E.J.
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.
H.A. Gasteiger, N.
Markovic, P.N. Ross Jr. and E.J.