a new class of advanced materials m agneli phase of titanium sub - oxides yibing huang magneli...

A new class of advanced materials

MAGNELI PHASE OF TITANIUM SUB-OXIDES Yibing Huang Magneli Materials LLC

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● Summary● Introduction to Magneli phase of Titanium sub-oxides

Crystal structure feature Key properties and their relation to structure

● Development History Atroverda and development of Ebonex In-house synthesis Atroverda process Key challenges in the commercialization of Magneli phase

● Magneli Materials BREAKTHROUGH Mass production Structural stablilization – a new class of MM

● Various studies and uses?● Reference

Table of Contents

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● Breakthrough is the mass production of new Stabilized Ti407

● High Corrosion Resistance in Acidic and Basic solutions● Ceramic material with high electrical conductivity● High electro chemical stability

Summary Page

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● Arne Magneli was one of the pioneers of crystallography.

Established the study of transition metal sub-oxides and shear plane dislocations

Paved the way for the discovery of conducting Titanates and Pervoskites

● Starting in the 1940’s, examined a variety of transition metal oxides materials to determine why they were lubricious and electrically conductive - When they should have been neither.

Early focus was Tungsten and Molybdenum sub-oxides Later work included Titanium and Vanadium sub-oxides

● He discovered that each featured dislocation planes in their crystalline structure

The dislocation planes accounted for their electrical conductivity and lubricious properties

A similar mechanism gives rise to graphite and graphene’s properties

● These materials now called “Magneli Phase” materials

Arne Magneli and Magneli Phase materials

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Arne Magnéli (1914-1996)

Magneli Phase sub-oxides of titanium are ceramic materials which have a graphite-like crystalline structure otherwise known as a Magneli Phase.

Magneli Phase sub-oxides of titanium have individually identifiable X-ray diffraction spectra and not simply doped titania or casual mixtures of TiOx.

Magneli phase titanium sub-oxides are a range of distinct compounds having a general formula

TinO2n-1 (n=4 - 10)

(e.g. Ti4O7,Ti5O9,Ti6O11… )

Titania Magneli Phase materials

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Magneli Phase materials Crystal Structure

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The structures of Magneli phase titanium oxides are based on, but distinguishable from, the rutile TiO2 crystal structure

They are all triclinic .

The crystals of Magneli phase are built up of TiO2 octahedra blocks which share edges and corners to form a slab and repeat in two dimensions.

In TinO2n-1, every nth layer has an oxygen deficiency, which leads to shear planes in the crystal structure.

This shear plane occurs at n spacing in the layers of octahedra. The higher value of n has greater shear plane interval.

● The Shear Planes provide Magneli phase oxides the pathway for the transfer of electrons and cause it to be electrically conductive in a similar level to graphite;

● The layers of refractory Rutile octahedra blocks provide it with chemical stability like TiO2;

● Ti4O7 is the most reduced Magneli phase, It has Rutile form of TiO2 with every 8th Oxygen removed;

● Ti4O7 has the highest number of shear planes occurring at the shortest spacing of these shear planes

● Ti4O7 has the highest electrical conductivity and chemical stability among all Magneli phase of titanium suboxides.

● When the n equals to 3 or less, the shear plane accommodation of the octahedra collapses and so does the crystallographic structure from triclinic to monoclinic.

Ti4O7 is by far the best known and most studied Magneli Phase material

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● Metal-like electrical conductivity Single crystal conductivity 1500 S/cm Ceramic conductivity similar to graphite

Key properties of Magneli phase materials

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● These materials were first isolated in the late 1970’s by Peter C.S. Hayfield while working for Imperial Metals Industries (IMI), a large UK based producer of titanium alloys.

● Hayfield named the material “Ebonex” after its deep blue-black color.

● Ebonex has been ever since produced by Atraverda, a UK company.

Magneli Phase materials and Ebonex

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● Metal-like electrical conductivity The Magneli phase ceramic materials usually contain a mixture of sub-stoichiometry. Ceramic electrical conductivity is higher with low n values


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● High corrosion resistance in aggressive acidic and basic solution Exceptionally robust in HF, BF4, PF6, HCl, KOH and other highly oxidizing

environments Exceptionally stable under electrically polarized conditions that makes very

high performance anodes and cathodes


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● High corrosion resistance in aggressive acidic and basic condition Only a few Magneli phase (Ti4O7/Ti5O9) have both high electrical

conductivity and chemical stability. Other titanium suboxides are not as chemically stable as Magneli phase

even though with better electrical conductivity.


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● Unique electrochemical properties Wide over-potential window that suppresses O2 and H2 evolution in water Exceptional catalyst retention – superior adhesion, less catalyst require Makes high performance cathode and anode


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● Lubricious and high wear resistance Similar to graphite but with higher wear resistance Makes as good wear and anti-scuffing coating as standard Mo-base coating

for inner-combustion engine piston ring .


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● Super hydrophilic Drying agent Electrical cable coating

● High microwave absorption Stronger absorption than

Silicon carbide Wave guide and stealth

coating

● Photo catalytic Water split

● Non-toxic and cost effective Environmental friendly Abundance in natural and

relatively low cost

Other properties of Magneli phase materials

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● Expensive to manufacture in bulk Requires a 2 step process with chemical

reduction in a H2 filled furnace!

● The Magneli Shear Planes are prone to oxidation

Ti4O7 can revert back to TiO2 when exposed to some conditions

● Shear Plane oxidation limits the forms in which Ti4O7 can be effective

Nano-scale structures (fibers, films, high surface area) are unstable

Very difficult to apply as a plasma sprayed coating or PVD film

● Makes poor conductive polymers Particle size and morphology cannot be

optimized for conductivity

Commercial Acceptance of Magneli Phase Materials has been slow due to:

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The Magneli Shear Planes are Ti4O7‘s weakness - providing access for re-oxidation to TiO2

● Reduction of high purity of TiO2 at elevated temperature

Hydrogen reduction Carbon/graphite reduction Ammonia reduction Metallic titanium reduction

Synthesis of Magneli Phase

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● Two steps fire process: Make TiO2 ceramic body by conventional ceramic process; Reduce the pre-fired porous ceramic body in hydrogen kiln to get mixed

Magneli phase titanium suboxides. Crash and mill to get powder.

Manufacturing of Magneli Phase – Atraverda, UK

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● Sophisticated equipment and process

Whole ceramic production line Hydrogen reduction production line

● Long time, low efficiency Two fire process needs over 50 hours Batch process for chemical reduction

● Safety issue Hydrogen gas kiln

● High energy consumption Ceramic fire 1300C Reduction 1100C

● Inferior quality and low consistency Hydrogen gas feed flow Hydrogen gas diffusion in porous

ceramic body

● High cost

Downsides of Atraverda manufacturing process

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Products of Atraverda manufacturing process

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Products of Atraverda manufacturing process

21XRD of Ebonex ceramic tube

● We have developed a new manufacture process and novel class of more advanced materials by through Structural Stabilization of the Magneli Shear Planes

Resists conversion to TiO2 when exposed to strong oxidizing conditions

● Greatly expands the forms in which it can be made Micro and Nano-scale structure powders Plasma sprayed coatings on low cost substrates (Ti , Al and stainless steel) High surface area reticulated foams Ceramic articles

● Economical to manufacture in high volumes and consistency

OUR MAGNELI Materials eliminate these issues

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● Substantially different from conventional Magneli Phase materials

Such as Ti4O7, Ti5O9, Ti6O11 and trade marked mixtures of these such as Ebonex™

New material retains all documented properties of Ti407, with the addition of being stable as nano-scale fibers and surface features.

Now possible to attain exceptional levels of effective potential intercalation sites.

New material allows application as coating directly onto low cost foils

Our Magneli Material is a novel class of materials

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● Substantially higher content of Ti4O7● Structural stabilized

Our Magneli Materials are superior

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● extensive research and demonstration of significant benefits from Stabized Ti407

● Primary applications : Energy storage Electro Winning Advanced Oxidation Process of water ????????? Electro Winning Cathodic Protection Lubrication

Commercial use of Magneli Phase materials is just starting

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● Magneli Materials LLC was formed to address this challenges by providing Volume supplies of high quality Magneli Materials in a

broad range of grades A central point for the dissemination of research and

knowledge relating to Magneli Phase materials Support for continued research in this area through

collaboration with• Academic research groups• Product developers and end users

● Our goal is to be the leading partner and supplier of choice for Magneli Materials We have brought together many of the prime movers in

this field and are expanding into the next generation of researchers

Our Mission

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● Industrial scale production facilities Powder, ceramics, nano-structures

● Novel APS coating technologies Titanium, aluminum, stainless steel successfully coated

and functional as anodes

● Application of MnO2 and other catalysts New low cost catalyst options are now possible

We have made substantial efforts to support our business

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● Powders - micron and nano-scale● Ceramics – plates and tubes● Coatings - Expanded Ti mesh● Conductive plastics – thermo-set● All can be supplied catalyzed or uncatalyzed

Currently available forms

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1. “The continuing development of Magneli phase titanium sub-oxides and EbonexR electrodes, Walsh F.C. Wills R.G.A. Electrochemical Acta, V55, Issue 22, 1st September 2012, p6342-6351

2. Electrodes based on Magnéli phase titanium oxides: the properties and applications of Ebonex® materials by J R Smith, F C Walsh, R L Clarke Journal of Applied Electrochemistry (1998) Volume: 28, Issue: 10, Publisher: Springer, Pages: 1021-1033

3. “Development of a new monolithic Ti4O7 Ebonex Ceramic, Hayfield P.C.S. Pub. Royal Society of Chemistry ISBN 0854049843

4. Ozone Generation at Ebonex and Ebonex / Lead Dioxide Electrodes'. Journal of Applied Electrochemistry 22, 200-203; Graves, J.E., Pletcher, D., Clarke, .R.L.

5. Cr(III) oxidation with lead dioxide-based anodes Authors: Devilliers D.; Dinh Thi M.T.; Mahe E.; Le Xuan Q. Electrochimica Acta, Volume 48, Number 28, 15 December 2003 , pp. 4301-4309(9)

6. The electrochemistry of Magnéli phase titanium oxide ceramic electrodes Part I. The deposition and properties of metal coatings. J. E. Graves, D. Pletcher, R. L. Clarke and F. C. Walsh, Journal of Applied Electrochemistry Volume 21, Number 10 (1991), 848-857, DOI: 10.1007/BF01042450

7. CSIRO Report Number DMP-098, Evaluation of the Effect of Ebonex® Additive on Lead-acid Battery Capacity at Different Discharge Rates, August 1995

8. Development of Supported Bifunctional Electrocatalysts for Unitized Regenerative Fuel Cells, G. Chen, S.R. Bare, and T.E. Mallouk. Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA UOP LLC, Des Plaines, Illinois 60017, USA

9. Lithium-Ion Intercalation into TiO2-B Nanowires† A. R. Armstrong, G. Armstrong, J. Canales, R. García, P. G. Bruce Article, Advanced Materials Volume 17, Issue 7, pages 862–865, April, 2005

10. Structural properties of Ce-doped strontium titanate for fuel cell applications Denis J. Cumming , John A. Kilner and Stephen Skinner J. Mater. Chem., 2011,21, 5021-5026 DOI: 10.1039/C0JM03680C

11. Synthesis of zinc titanate for Dye Sensitized Solar Cell (DSSC) application Azman bin Azumi, Azman (2010) Synthesis of zinc titanate for Dye Sensitized Solar Cell (DSSC) application. Universiti Teknologi Petronas. (Unpublished)

12. Moderate hydrothermal synthesis of potassium titanate nanowires. Z.-Y. Yuan, X.-B. Zhang and B.-L. Su. APPLIED PHYSICS A: MATERIALS SCIENCE & PROCESSING Volume 78, Number 7 (2004), 1063-1066, DOI: 10.1007/s00339-003-2165-x

1. Batteries and Fuel Cells

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13. "Electrochemical Behavior of Platinized Ebonex® Electrodes". Int. J. Electrochem. Sci., 7 (2012) 7915 - 7926. Authors: Olga Kasian, Tatiana Luk’yanenko, Alexander Velichenko (Ukrainian State University of Chemical Technology, Gagarin ave. 8, 49005 Dnipropetrovsk, Ukraine); Rossano Amadelli (ISOF-CNR and Dipartimento di Chimica, Università di Ferrara, via Borsari 46, Ferrara, Italy).

14. Development of Supported Bifunctional Electrocatalysts for Unitized Regenerative Fuel CellsGuoying Chen (Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA), Simon R. Bare, UOP LLC, Des Plaines, Illinois 60017, USA. Pub. Journal of The Electrochemical Society, 149 A1092-A1099, 2002.

15. Stability of Corrosion-Resistant Magnéli-Phase Ti4O7-Supported PEMFC. Auth. Tsutomu Ioroi, Hiroshi Senoh,Zyun Siroma, Shin-ichi Yamazaki, Naoko Fujiwara, and Kazuaki Yasuda. NIAIST, Japan. Pub. Catalysts ECS Trans. 2007 11(1): 1041-1048

16. Fiber-like nanostructured Ti4O7 used as durable fuel cell catalyst support in oxygen reduction catalysis. Chuanhao Yao, Fan Li, Xiang Lia (College of Environmental & Energy Engineering, Beijing University of Technology, Pingle yuan 100, Beijing, P.R. China) and Dingguo Xia. (College of Engineering, Peking University, Beijing 100871, P.R. China). Pub: J. Mater. Chem., 2012,22, 16560-16565 DOI: 10.1039/C2JM32866F First published online 25 Jun 2012

17. Ti4O7 supported Ru@Pt core–shell catalyst for CO-tolerance in PEM fuel cell hydrogen oxidation reaction. Lei Zhang, Jenny Kim, Jiujun Zhang, Feihong Nan, Nicolas Gauquelin, Gianluigi A. Botton, Ping He, Rajesh Bashyam and Shanna Knights. Applied Energy, 2013, vol. 103, issue C, pages 507-513

18. Cortie, B., Xiao, L., Erdei, L.: `Thermal stability of (KxNayH1–x–y)2Ti6O13 nanofibers', Eur. J. Inorg. Chem., 2011, 33, p. 5087-5095

19. Wang, C., Deng, Z., Li, Y.: `The synthesis of nanocrystalline anatase and rutile titania in mixed organic media', Inorg. Chem., 2001, 40, p. 5210-5214BSA 11-08: Nanoscale Magnéli Phases of Titanium Oxide Increase Electrode Capacity. BNL Reference Number: BSA 11-08

20. Magneli phase Ti4O7 electrode for oxygen reduction reaction and its implication for zinc-air rechargeable batteries. Xiaoxia Li, Aaron Li Zhu, Wei Qu, Haijiang Wang, Rob Hui, Lei Zhang, Jiujun Zhang Institute for Fuel Cell Innovation, National Research Council of Canada, 4250 Wesbrook Mall, Vancouver, BC V6P 1W5, Canada. Electrochimica Acta, Volume 55 Issue 20, August 2010 p5891-5898 http://dx.doi.org/10.1016/j.electacta.2010.05.041

1. Batteries and Fuel Cells (continued)

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21. DE P 195 48 718 C1, Reibungsbelastetes Bauteil eines Verbrennungsmotors (Tribological stressed components for internal combustion engines)

22. M. Woydt, “Review on Lubricious Oxides and Their Practical Importance In: Handbook of Surface Modifications and Processing”: Physical & Chemical Tribological Methodologies, edited by: G.E. Totten; Marcel Dekker, New York

23. M.N. Gardos. “The effect of anion vacancies on the tribological properties of rutile (TiO2-x)”: Tribology Transactions, 1989, 32, 30-31

24. M.N. Gardos. “The effect of Magnéli Phases on the Tribological Properties of Polycrystalline Rutile”. Proc. 6th Int. Congress on tribology, 1993, Vol. 3, p. 201-206

25. Woydt, M. , J. Kadoori, H. Hausner and K.-H. Habig. “Development of engineering ceramics according to tribological considerations” (bilingual) Cfi/Ber. DKG, Vol. 67, No. 4, (1990), p.123-130 (Journal of the German Ceramic Society)

26. O. Storz, H. Gasthuber and M. Woydt. “Tribological properties of thermal-sprayed Magnéli-type coatings with different stoichiometries (TinO2n-1)”. Surface and Coatings Technology 140 (2000) 76-81

2. Tribology

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27. “The Electrolytic Generation of Chlorine for the disinfection of private water supplies” Final Report, Contract 7/7/138, Project D.U. 194, University of Newcastle upon Tyne, UK 1991. Final Report to the UK Department of the Environment

28. Electrolytic Cell for the Inactivation of Viruses in Water” Project DW I0743, University of Newcastle upon Tyne, UK 1993, Final Report to UK Department of the Environment

29. Chemical Degradation Methods for Wastes and Pollutants: Environmental and Industrial Applications edited by Matthew A. Tarr. CRC Press, Aug 8, 2003 - Science - 314 pages

30. Yang, D., Sarina, S., Zhu, H.: `Capturing radioactive Cs+ and I− from water with titanate nanofibers and nanotubes', Angew. Chem. Int. Ed. Engl., 2011, 5, p. 10594-10598

31. Yang, D., Zheng, Z., Yuan, Y.: `Sorption induced structural deformation of sodium hexa-titanate nanofibers and their ability to selectively trap radioactive Ra(II) ions from water', Phys. Chem. Chem. Phys., 2010, 12, p. 1271-127

32. "The use of Ebonex electrodes for the electrochemical removal of nitrate ion from water" Pub> Canadian Journal of Chemistry, 2012, 90(8): 666-674, 10.1139/v2012-048. Auth: David Kearney, Dorin Bejan, Nigel J. Bunce, Electrochemical Technology Centre, Chemistry Department, University of Guelph, Guelph, ON N1G 2W1, Canada.

3. Water Treatment

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Materials Handbook – A concise Desktop Reference

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a new class of advanced materials m agneli phase of titanium sub - oxides yibing huang magneli...

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