Materials Research Activities

Whittingham publication list (incl. abstracts)
with R. W. Helliwell & R. A. Huggins, U.S. Govt. Res. Develop. Report 69 (1969), 158


with Robert 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]

with Robert 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 electrolyte.
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



‘Experimental 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.

with Robert A. Huggins, ‘Transport properties of inorganic bronzes', ibid., 645-652

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.

MSW patents: Belgium 819,672 issued 1975; US 4,040,917 and 4,007,055 both issued 1977


MSW, J. Chem. Soc. Chem. Commun., 1974, 328

MSW, ‘The 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.



‘Mechanism of reduction of the fluorographite cathode', Journal of the Electrochemical Society, 122 (1975), 5

Arne 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]

‘Free 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]

MSW, Electrochim. Acta, 20 (1975), 575

MSW and Fred R. Gamble, “The lithium intercalated of the transition metal dichalcogenides”, Materials Research Bulletin, 10 (1975), 363-372

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]


Silbernagel and MSW, “The physical properties of the NaxTiS2 intercalation compounds: A synthetic and NMR study”, Materials Research Bulletin, 11 (1976), 29-36

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]

‘Electrical energy storage and intercalation chemistry', Science, 192 (1976), 1126-1127

The electrochemical 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.

‘The 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]


with Martin B. Dines, ‘n-Butyllithium – An effective general cathode screening agent', Journal of the Electrochemical Society, 124 (1977), 1387-1388

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, 784

Thompson & 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 of x-values

·         Little change in free energy over the composition range of x

·         Little structural change on reaction

·         High diffusivity of the alkali ion into the structure

·         Be an electrical conductor

·         React in a reversible manner

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]

MSW & 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 obtained elsewhere.

MSW, “Material Aspects of the New Batteries”, in Materials Science in Energy Technology, edited by Libowitz and MSW, New York: Academic Press, 1979. 455-490

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 of intercalation.


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



MSW, R. 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 compounds.
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.

lots of 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.



MSW & 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.


MSW, “Intercalation 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.


"Sodium ion conduction in single crystal vermiculite",

The 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 10–8 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, 391-

Hydrothermal synthesis of new metastable phases preparation and intercalation of a new layered titanium phosphate

Yingjeng James Li and M. Stanley Whittingham

Department 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.



MSW, “Insertion electrodes as SMART materials: the first 25 years and future promises”, Solid State Ionics, 134 (2000), 169-178 


The role 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), 109-115

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), 445-447

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), 69-71

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.