with R. W. Helliwell & R. A. Huggins, U.S.
Govt. Res. Develop. Report 69 (1969), 158
A. Huggins, Transport properties of silver beta alumina, Journal
of the Electrochemical Society, 118 (1971), 1-6
The total electrical conductivity and the electronic
conductivity in silver beta alumina have been determined between 230
and 8000C over a wide range of oxygen partial pressure using
a-c and d-c techniques. The ionic transference number was found to be
very close to unity under all conditions. Comparison of these measurements
with tracer diffusion studies shows that the diffusion of silver ions
takes place by an interstitialcy mechanism. [Submitted 27.4.1970, revised
ms. received ca. 27.8.1970, published Jan 1971]
A. Huggins, Measurement of sodium ion transport in beta alumina
using reversible solid electrodes', Journal of Chemical Physics,
54 (1971), 414-416
Previously reported measurements of
the diffusion of sodium ions in beta alumina indicated that this material
might be a very good ionic conductor at relatively low temperatures.
However, the lack of a suitable nonpolarizing electrode material has
prevented the accurate determination of the magnitude of the conductivity
to date. It is the purpose of this paper to report a series of measurements
using sodium tungsten bronzes as a new type of solid electrolyte that
is reversible to sodium ions and applicable over a wide range of temperature
at low oxygen partial pressures. The transport of sodium ions takes
place by an interstitialcy mechanism. [Received 31.7.1970, published
1 January 1971]
with Robert A. Huggins, Electrochemical preparation
and characterization of alkali metal tungsten bronzes, MxWO3', in Solid
State Chemistry Proceedings of the 5th Materials Research
Symposium sponsored by the Institute for Materials Research, National
Bureau of Standards, October 18-21, 1971 held at Gaithersburg, Maryland,
edited by Robert S. Roth & Samuel J. Schneider Jr., NBS Special
Publication 364, Washington DC: U.S. Department of Commerce and National
Bureau of Standards, 1972, 51-62
The tungsten bronzes are nonstoichiometric
compounds of general formula MxWO3 where M is usually a monovalent cation
and x is in the range 0 to 1. They are of much interest particularly
because of their exceptionally wide stoichiometry ranges. Although discovered
originally by Wöhler in 1824, there is still today no published thermodynamic
data on any tungsten bronze system. It is the purpose of this paper
to discuss the thermodynamic aspects of the processes occurring during
the electrolytic decomposition of tungsten melts to form sodium and
potassium tungsten bronzes. [Issued July 1972]
Interest in beta alumina was sparked
off by pioneering work at the Ford Motor Company with a revolutionary
approach to the battery problem: using liquid electrodes and a solid
By use of a group of novel non-polarizing solid electrodes,
which are fully reversible to the monovalent cation, it has been possible
to study the ionic conductivity of a series of beta aluminas containing
alkali metals as well as thallium over a wide temperature range. The
electronic conductivity of silver beta alumina has also been determined
by use of the Wagner asymmetric polarization technique over wide ranges
of temperature and oxygen partial pressure.
in Conf. Layered Mater., Monterey, California,
August 1972? [not found in MIT library catalogue]
with Robert A. Huggins, in Reactivity of Solids,
edited by J. S. Anderson et al, London: Chapman & Hall, 1972, 125
[bestilt fra RSC, ankommer 3. januar 2001]
with P. S. Connell & R. A. Huggins, Jn. Solid
State Chemistry, 5 (1972), 321
Determination of Fast Ion Transport in Solids', in Fast Ion
Transport in Solids Proceedings of the NATO sponsored Advanced
Study Institute on Fast Ion Transport in Solids, Solid State Batteries
and Devices, Belgirate, Italy 5-15 September 1972, edited by W.
van Gool, Amsterdam & London: North-Holland, New York: American
Elsevier, 1973, 429-438
In a search for materials exhibiting
fast ion transport for use as the electrolyte or eledctrode component
of solid state battery systems, one needs both a rapid search tool to
give an indication of whether ions move and a subsequent technique to
accurately determine the diffusivities of the mobile species.
Two methods that are particularly applicable to a rapid
survey are ion exchange and nuclear magnetic resonance line-narrowing.
For accurate determination of fast ion transport in solids the most
satisfactory technique is the direct measurement of the ionic conductivity.
However, this is very difficult to accomplish when the ions move rapidly
because of interfacial polarisation; a new technique involves the use
of solid non-stoichiometric compounds reversible to both the mobile
specie and to electrons is discussed.
The advantages and disadvantages of each method will
be compared and contrasted relative to its use as a screening or quantitative
tool and the properties of the materials under test.
A. Huggins, Transport properties of inorganic bronzes', ibid.,
The structure of a number of
materials are built up by corner or edge sharing of BO6 octahedra. The
perovskite structure represents the simplest arrangement of these octahedra.
These building units are often arranged so that there are large channels
running through the structure, such as found in the hexagonal tungsten
bronzes and in the hollandites; the low valence M ions which reside
in these channels are expected to show a high diffusivity. Results obtained
on the diffusivity of monovalent and divalent atoms in this type of
structure are discussed and suggestions are made concerning other materials
of this type that might be expected to exhibit high ionic diffusivity.
Belgium 819,672 issued 1975; US 4,040,917 and 4,007,055 both issued
Chem. Soc. Chem. Commun., 1974, 328
hydrated intercalation complexes of the layered disulfides', Materials
Research Bulletin, 9 (1974), 1681-1690
The layered disulfides of the group IVB, VB and VIB
transition metals are able to intercalate a wide range of metals and
other electron donors into the Van der Waals gap of their structures.
Gamble et al reported that aqueous solutions of the alkali metal and
ammonium hydroxides would react with TaS2 resulting in a considerable
expansion of the crystal lattice and an enhanced superconducting transition
temperature. Very little is known of the chemical nature of these compounds;
this paper presents a study of the role of hydration in intercalation.
The ammonia and alkali metal
intercalation compounds of the transition metal disulfides form hydration
complexes in which the intercalated species are separated by a ring
of water. This reaction is readily reversed on heating indicative of
the salt-like nature, Mx+TaS2x-, of the intercalates. The crystal structures
are a function of the ionic size of the intercalated atoms or molecule
and the transition metal.
of reduction of the fluorographite cathode', Journal of the
Electrochemical Society, 122 (1975), 5
Hessenbruch's abstract: The object of this paper is to suggest an alternative
hypothesis for the reaction of graphite with fluorine in which the open
circuit voltage is determined not by the formation of lithium fluoride
and graphite but rather by an intermediate product of the reaction:
Li + 1/nx (CF)n → 1/x (CLixF), an intermediate ternary nonstoichiometric phase.
Such phases are probably more common than has heretofore been realized.
[Published April 1975]
energy of formation of sodium tungsten bronzes, NaxWO3', Journal of the Electrochemical
Society, 122 (1975), 713-714
Arne Hessenbruch's abstract:
The sodium tungsten bronzes are highly nonstoichiometric compounds and
metallic conductors. They have therefore been used as electrodes for
both fuel cells and conductivity cells; yet until recently nothing quantitative
was known about their thermodynamic properties. This paper reports some
electrochemical studies of the sodium activity in these materials for
0.3 < x < 0.8 at ambient temperatures.
Emf is higher for V2O5 than for either MoO3 or WO3,
which may be expected from the increase in stability of the highest
oxidation states in going down the periodic table. In these cases, alkali
metal ions, in particular lithium, can be readily intercalated without
any appreciable change in their structures forming a ternary phase,
LixV2O5, or LixMoO3. [Published May 1975]
Acta, 20 (1975), 575
Fred R. Gamble, The lithium intercalated of the transition metal
dichalcogenides, Materials Research Bulletin, 10 (1975),
The lithium intercalation compounds
of the layered transition metal dichalcogenides, prepared by reaction
with n-butyl lithium, have been characterized by x-ray analysis. The
group IVB and VB compounds (prepared this way) are stoichiometric and
stable; the intercalation proceeds by simple expansion of the lattice
at the Van der Waals gap. The group VIB chalcogenides, SnS2 and ReSe2
do not form lithium intercalation compounds with the exception of MoS2
and that appears to be metastable.
(Much of the recent effort on these
materials has been aimed at understanding their superconducting properties.
These properties are markedly changed on intercalation, thus the superconducting
transition temperature is raised from 0.8K of 2H-TaS2 to 4.2 and 5.3
on intercalation of ammonia and hydrated potassium. To date the highest
transition temperatures have been observed in the alkali metal complexes
for both TaS2 and MoS2.)
[Received 14.3.1975, published 1975]
and MSW, The physical properties of the NaxTiS2 intercalation compounds: A synthetic
and NMR study, Materials Research Bulletin, 11 (1976),
Considerable recent attention has been directed to
several classes of nonstoichiometric compounds containing alkali metal
atoms, most notably the tungsten bronzes and the beta aluminas, because
of their potential utility in electrical energy storage systems. A third
group of such materials are the layered transition metal dichalcogenides
in which alkali metal atoms can be incorporated.
This paper describes an NMR study of these sodium intercalates,
and these properties are related to structural and synthetic studies
and compared with the LixTiS2 compounds, as well as with the bronzes
and beta alumina.
The process of intercalation in the NaxTiS2 system
involves the donation of electrons from the Na atoms to the TiS2 layers,
as for the LiTX2 compounds and the sodium tungsten bronzes. Differing signs of the Knight shifts in the bronzes suggest a difference
of Fermi surface character in the two cases. Variations of Fermi surface
properties with sodium concentration and site symmetry suggests a significant
influence of the Na atoms on the conduction band of the TiS2 layers.
[Received 5.11.1975, published 1976]
energy storage and intercalation chemistry', Science, 192 (1976),
reaction of layered titanium disulfide with lithium giving the intercalation
compound lithium titanium disulfide is the basis of a new battery system.
This reaction occurs very rapidly and in a highly reversible manner
at ambient temperatures as a result of structural retention. Titanium
disulfide is one of a new generation of solid cathode materials.
role of ternary phases in cathode reactions', Journal of the
Electrochemical Society, 123 (1976), 315-320
The cell reactions between lithium and several transition
metal oxides and sulfides have been found to produce ternary phases
and not the formation of lithium oxide or sulfide as previously proposed.
These reactions, at 25 degrees C, take place with essential retention
of the crystalline lattice, thus facilitating secondary cathodic behavior.
It is found that cell reversibility is optimized when no chemical bonds
are broken during discharge, that is, where ternary phases are formed
by an intercalation reaction and where a broad range of nonstoichiometry
exists as in the system Li/TiS2. Where some chemical bonds are broken,
as for V2O5 and TiS3, partial or difficult reversibility is found, but
when all the bonds are broken as for example in CuS, the cell only exhibits
primary characteristics. [Ms. submitted 7.7.1975, revised 10.10.1975,
published March 1976]
B. Dines, n-Butyllithium An effective general cathode screening
agent', Journal of the Electrochemical Society, 124 (1977),
Currently, high energy density lithium
storage systems are the focus of intense interest and expectation. In
order to scan and characterize oxidants as potential cathodes, it would
be very useful to have a reliable chemical agent which could, in effect,
mimic the half-cell reaction under consideration. Although reagents
formed by dissolving alkali metals in ammonia, polyamines, polynuclear
aromatic solutions in ethers, or hexamethyl phosphoramide might be used,
they have a number of shortcomings. Their reactions are difficult to
run, since they involve extremely reactive materials, very dark opaque
media, their polar solvents can also partake in the reaction, and it
is difficult to separate the product from residual reagent. It would
be preferable to have instead an agent whose lithium activity is more
on the order of a volt or so below the alkali itself. We report that
n-buytl lithium serves as such an agent. [Ms. submitted 21.3.1977, revised
11.4.1977, published September 1977]
MSW, in McIntyre, Srinivasan, Will (eds.), Proc.
Symp. Electrode Materials and Processes for Energy Conversion and Storage,
& MSW, Transition metal phosphorus trisulfides as battery
cathodes, Materials Research Bulletin, 12 (1977), 741-744
Although alkali metal batteries have
been studied for many decades, it is only recently that the critical
importance of the formation of ternary compounds for cell reversibility
has been recognized. Much work was first aimed at the tungsten and vanadium
bronzes, MxWO3 and MxV2O5, as cathodes, but the diffusivity of the alkali
ions was too low. The key requirements for a useful cathode material
forming a ternary phase with alkali metal ions are:
A high free
energy of formation
A wide range
in free energy over the composition range of x
change on reaction
of the alkali ion into the structure
Be an electrical
React in a
TMD perform well as cathodes. Transition
metal trisulfides also exhibit electrochemical activity. Nickel phosphorus
trisulfide will react with more than four lithium resulting in a cell
with a theoretical energy density double that of TiS2. If this high
theoretical energy density is truly electrochemically reversible then
the low cost of the component elements, the reasonable conductivity
of the iron and nickel compounds, and the ambient temperature operation,
will make the Li-MPS3 batteries promising candidates for electric vehicle
propulsion (patent applied for). [Received 31.5.1977, published 1977]
Silbernagel, NMR Techniques for Studying Ionic Diffusion,
in Solid Electrolytes General Principles, Characterization,
Materials Applications, New York: Academic Press, 1978, 93-108
NMR is a particularly flexible tool
that can provide valuable information about the degree of ionization,
environment, and motional characteristics of the constituent nuclei.
It may be applied to single crystals or powdered samples of either insulating
or conducting materials. Both short- and long-range motion can be examined.
Inequivalent sets of atoms can often be differentiated. However, because
it is difficult in simple NMR studies to separate local and extended
motion and since they are not sensitive to interfacial affects, NMR
observations should be complemented by conductivity studies. However,
the absence of motional effects on NMR is a very strong indication of
low diffusion. The simplest screening technique is to measure the linewidth
as a function of temperature.
Chemistry of intercalation compounds: metal
guests in chalcogenide hosts', Progress in Solid State Chemistry,
12 (1978), 41-99
To date, only the dichalcogenides
have conclusively been shown to form true intercalation compounds, that
is compounds where the host may be recovered in its original form on
removal of the guest species. Much effort is likely to be spent on the
oxide compounds in the next few years both to understand their insertion
compounds and to find those that might be applicable in electrodes for
energy storage or display purposes. A few have been identified here,
and others that fulfill the following three criteria are the most likely
candidates. Structures that:
are layered or have accessible tunnel sites
have an accessible electronic band structure and high energy of formation
contain transition metal ions in their higher oxidation states.
Progress will be most rapid in this
area when the materials, whose properties are being studied are well
characterized chemically and structurally so that measurements made
in one laboratory can be compared in a meaningful manner with those
Aspects of the New Batteries, in Materials Science in Energy
Technology, edited by Libowitz and MSW, New York: Academic Press,
In the short term it is likely that
improved lead-acid cells will be used to power the second generation
road vehicles (milk floats being the first) that might reasonably be
used by postal, telephone repair and metropolitan delivery fleets. In
the long term, advanced batteries will probably utilize the alkali metals
as anodes and will operate at or around ambient temperature. Present
trends would seem to suggest that a liquid electrolyte will be used in conjunction
with a solid cathode. We are only now beginning to understand the phenomena
with A. J. Jacobson and R. R. Chianelli, Amorphous molybdenum
disulfide cathodes', Journal of the
Electrochemical Society, 126 (1979), 2277-2278
We report electrochemical data on
amorphous MoS2 prepared at ambient temperatures by the reaction of LiS2
with molybdenum chloride. This synthetic technique gives materials with
properties radically different from those commonly produced at high
temperatures, such as a substantially larger capacity for electrochemical
reaction with lithium and high reversibility
R. Chianelli, A. J. Jacobson, Amorphous cathodes for lithium batteries,
in Murphy, Broadhead, Steele (eds.), Materials for Advanced Batteries,
New York & London: Plenum Press, 1980, 291-299
The higher capacity of the amorphous
over crystalline molybdenum disulfide is presumably associated with
the disordered structure which prevents the decomposition to lithium
sulfide found for the latter. Ongoing structural studies on the di-
and tri-sulfides using EXAFS and radial distribution studies clearly
show that there are marked differences between the amorphous and crystalline
The energy storage capacities of these amorphous cathode
materials is very high. It remains to be proved whether they can cycle
as well as TiS2.
authors, ibid., 343-347
Perhaps the most important
and least understood area of electrode kinetics is the influence of
electric field gradients on rate. To date, the most studied materials
have been layered or pseudo-one dimensional compounds. Lithium has been
the preferred cation. Work on other structures such as 3d Chevrel structures
or structures containing interconnecting tunnels may lead to advances.
Sodium as a cation should be studied. Systems intercalating anions (eg.
F-) should be studied. Disordered analogs of known crystalline intercalation
systems may present further opportunities. Rocking-chair batteries (Li
and Na alternately inserted in anode and cathode during charge and discharge)
are promising. New liquid electrolytes should be investigated.
John A. Panella, Formation of stoichiometric titanium disulfide,
Materials Research Bulletin, 16 (1981), 37-45
Any transition metal in the van der
Waals layer impedes intercalation by restricting the expansion of the
crystalline lattice. Thus, the disulfides must not only be stoichiometric
but also formed at sufficiently low temperatures to prevent the excitation
of Ti ions into the layer. Sulfur pressure also plays an important role.
The stoichiometric compound is best formed from titanium sponge at 450-600
degrees C in a temperature gradient that fixes the sulfur pressure.
This TiS2 has been discharged more than 600 times.
chemistry: An introduction, in MSW & Jacobsen (eds.), Intercalation
Chemistry, New York: Academic Press, 1982, 1-18
The essential feature of the intercalation
reaction, and that which makes its study so exciting and profitable,
is that guest and host experience some degree, along a spectrum from
subtle to extreme, of perturbation in their geometric, chemical, optical,
and electronic properties. There is considerable latitude available
to the worker for controlling many of the parameters in order to tailor
the behavior desired.
TiS2 cells have been manufactured as small button cells
for watches. However, before large lithium batteries can be made commercially
available, safe high-rate electrolytes have to be found.
ion conduction in single crystal vermiculite",
diffusion of sodium in single crystals of Llano vermiculite has been
studied using conductivity measurements. The crystals were maintained
in the bilayer water state by using aqueous contacts. The diffusion
coefficient at 25°C
was found to be 1.9 X 108 cm2/s, with
an enthalpy of motion of 11.7 kcals/mole. These values are in good
agreement with sodium tracer and proton NMR studies and indicate that
the sodium ions probably diffuse with their hydration spheres. The
conductivity in the range 10 to 90°C
is less than that in sodium beta alumina and much less than that of
either surface clay cations or of aqueous sodium chloride solutions.
Solid State Ionics, 63-1993,
synthesis of new metastable phases preparation and intercalation of
a new layered titanium phosphate
Yingjeng James Li and M. Stanley
of Chemistry and Materials Research Center, State University of New
York at Binghamton, Binghamton, NY 13902-6000, USA
We have investigated
the formation and reactivity of new metastable phases using mild hydrothermal
synthesis. Following the characterization of two new open structure
sodium tungsten oxides, we found that by using a small cationic template
we were able to synthesize a new layered structure titanium phosphate.
Preliminary chemical analysis of this compound indicates that its
hydrogen form has the formula TiO(OH)(H2PO4)·2H20.
31P MAS-NMR indicates that each phosphorus has two OH groups.
This solid acid is readily swelled on reaction with organic amines.
MSW, Chen R., T. Chirayil and P. Zavalij, The
intercalation and hydrothermal chemistry of solid electrodes,
Solid State Ionics, 94 (1997), 227-238
Intercalation chemistry plays a key
role in the electrochemical reduction and oxidation by lithium of many
solid electrodes, including transition metal compounds and graphite.
For 25 years, from TiS2 and graphite to LixCoO2 and LiMn2O4, the electrode
reactions of such intercalation compounds have been extensively studied.
Much emphasis has been placed on two simple classes of structures, layer
and spinel, both of which are formed by LixTiS2 and LixMnO2. More recently,
much effort has been directed at synthesizing new structures that might
show enhanced electrochemical activity. Soft chemistry approaches have
been harnessed for this purpose. Mild hydrothermal reactions are one
such approach. Several new vanadium oxides have been formed, as well
as layered forms of manganese oxide. A number of these new compounds
reversibly react with lithium and therefore may be used as the cathode
in lithium batteries.
F. Zhang, P. Y. Zavalij
and MSW, Hydrothermal
synthesis of iron and zinc double vanadium oxides using the tetramethyl
ammonium ion, Materials Research Bulletin, 32 (1997), 701-707
We have studied the hydrothermal synthesis
of tetramethyl ammonium vanadium oxides that contain an additional transition
metal, such as iron or zinc, in order to stabilize the layered structure
of vanadium oxide for electrochemical redox reactions with lithium.
Addition of the lower cost iron and zinc is also beneficial for commercial
application. Several new layered structures which contain double sheets
of V2O5 have been formed and characterized. The
iron compound contains the TMA ion. Their structures and electrochemical
behavior are reported.
Fan Zhang, Peter Zavalij
and MSW, Hydrothermal synthesis and electrochemistry of a manganese
vanadium oxide, -MnV2O5,
Electrochemistry Communications, 1 (1999), 564-567
A new manganese
vanadium oxide MnV2O5 has been synthesized using a mild hydrothermal
reaction. MnV2O5 crystallizes in the orthorhombic system, space group
Pnma, a=9.7585(2) Å, b=3.5825(1) Å, c=11.2653(2) Å. It is isostructural
to -LiV2O5. It reacts readily and reversibly with lithium, with a stable
capacity but with a large polarization.
Insertion electrodes as SMART materials: the first 25 years and
future promises, Solid State Ionics, 134 (2000), 169-178
of intercalation/insertion reactions in battery electrodes was first
recognized just over 25 years ago. From the first prototypical titanium
disulfide cells, the technology has more recently been commercialized
by Sony in the Li-ion cell using a cobalt oxide insertion cathode and
a carbon insertion anode. These cells have proved themselves highly
successful in the field in small devices, such as cellular phones and
portable computers. However, their energy density is no higher than
the titanium sulfide system and they are too expensive for large-scale
application. Therefore, the search is on for lower cost cathodes that
have at least double the energy density of the present systems. The
research trends and future prospects are discussed.
MSW and Peter Y. Zavalij,
Manganese dioxides as cathodes for lithium rechargeable cells:
the stability challenge, Solid State Ionics, 131 (2000),
A wide range
of manganese oxides is under study for possible use as the cathode of
high energy density batteries. The spinel, LiMn2O4, although the most
studied has a relatively low energy density and appears unstable under
charge. This review emphasizes non-spinel oxides, in particular those
with layered or tunnel structures that offer enhanced behavior in lithium
ion and lithium polymer cells. A major focus is on stabilizing these
manganese oxide structures against conversion to the spinel phase.
Fan Zhang, Katana
Ngala and MSW, Synthesis and electrochemistry of a vanadium-pillared
manganese oxide, Electrochemistry Communications, 2 (2000),
A new manganese
dioxide pillared by vanadium oxide species has been synthesized hydrothermally
from permanganate. It has the electrochemically active MnO2
layer structure, which has been extensively studied as a battery cathode.
The vanadium oxide ions, together with the water molecules, reside in
between the oxide sheets; dehydration occurs without structural change.
The (VOy)0.1MnO2·nH2O has a rhombohedral
structure, with hexagonal parameters a=2.843(6) Å, c=22.08(2) Å. It
reacts readily with lithium with a capacity around 150 mAh g-1;
the pillar ions do not appear to impede reaction.
Fan Zhang & MSW,
Hydrothermal synthesis and electrochemistry of a -type manganese
vanadium oxide, Electrochemistry Communications, 2 (2000),
A new manganese
vanadium oxide containing double sheets of V2O5 layers has been synthesized
hydrothermally in the presence of tetramethylammonium ions. It has the
electrochemically active -V2O5 structure, variants of which are found
in V6O13 and xerogel vanadium oxides. The manganese ions, together with
the N(CH3)4 ions, reside in a disordered manner between the oxide sheets.
The -type [N(CH3)4]zMnyV2O5·nH2O has a monoclinic structure, a=11.66(2)
Å, b=3.610(9) Å, c=13.91(4) Å, =108.8(2)°. It reacts readily with lithium
with a capacity exceeding 220 mAh g-1; the organic ions do not impede
reaction as in the single sheet V2O5 materials, such as N(CH3)4V3O7.