Lithium titanate

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Lithium titanate
Identifiers
CAS number 12031-82-2 YesY
PubChem 160968
Properties
Molecular formula Li2TiO3
Molar mass 109.76
Appearance Off-white powder
Density 3.43 g/cm3 [1]
Melting point 1,533 °C (2,791 °F; 1,806 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Lithium titanate (full name lithium metatitanate) is a compound containing lithium and titanium. It is an off-white powder at room temperature and has the chemical formula Li2TiO3.

It is the anode component of the fast recharging lithium-titanate battery. It is also used as an additive in porcelain enamels and ceramic insulating bodies based on titanates. It is frequently utilized as a flux due to its good stability.[2] In recent years, along with other Lithium ceramics, metatitanate pebbles have been the subject of research efforts towards tritium breeding materials in nuclear fusion applications.

Crystallization[edit]

The most common crystallization of Li2TiO3 is a monoclinic system.[3] A monoclinic system of crystallization is defined as three unequal axes with one oblique intersection.[4]

The stable monoclinic polymorph is also known as β-Li2TiO3. Additionally a high temperature cubic phase exhibiting solid-solution type behavior is referred to as γ-Li2TiO3 and is known to form reversibly above temperatures in the range 1150°-1250 °C.[5] A metastable cubic phase, isostructural with γ-Li2TiO3 is referred to as α-Li2TiO3 and is known to form from low temperature synthesis procedures and transforms to the stable β phase at temperatures around 400 °C.[6]

Uses in sintering[edit]

The sintering process is taking a powder, putting it into a mold and heating it to below its melting point. Sintering is based on atomic diffusion, the atoms in the powder particle diffuse into surrounding particles eventually forming a solid or porous material.

It has been discovered that Li2TiO3 powders have a high purity and good sintering ability.[7]

Uses as a cathode[edit]

Molten carbonate fuel cells[edit]

Lithium titanate is used as a cathode in layer one of a double layer cathode for molten carbonate fuel cells. These fuel cells have two material layers, layer 1 and layer 2, which allow for the production of high power molten carbonate fuel cells that work more efficiently.[8]

Lithium ion batteries[edit]

Li2TiO3 is used in the cathode of some lithium-ion batteries, along with an aqueous binder and a conducting agent. Li2TiO3 is used because it is capable of stabilizing the high capacity cathode conducting agents; LiMO2 (M=Fe, Mn, Cr, Ni). Li2TiO3 and the conduction agents (LiMO2) are layered in order to create the cathode material. These layers allow for the occurrence of lithium diffusion.

Lithium-titanate battery[edit]

The lithium–titanate battery is a rechargeable battery that is much faster to charge than other lithium-ion batteries. It differs from other lithium-ion batteries because it uses lithium-titanate on the anode surface rather than carbon. This is advantageous because it does not create an SEI layer (Solid Electrolyte Interface), which acts as a barrier to the ingress and egress of Li-ion to and from the anode. This allows lithium-titanate batteries to be recharged more quickly and provide higher currents when necessary. A disadvantage of the lithium-titanate battery is a much lower capacity and voltage than the conventional lithium-ion battery. The lithium-titanate battery is currently being used in battery electric vehicles and other specialist applications.

Synthesis of lithium titanate breeder powder[edit]

Li2TiO3 powder is most commonly prepared by the mixing of lithium carbonate, Ti-nitrate solution, and citric acid followed by calcination, compaction, and sintering. The nanocrystalline material created is used as a breeder powder due to its high purity and activity.[9]

Tritium breeding[edit]

Fusion reactions, such as those in the proposed ITER thermonuclear demonstrator reactor, are fueled by tritium and deuterium. Tritium resources are extremely limited in their availability, with total resources currently estimated at twenty kilograms. Lithium-containing ceramic pebbles can be used as solid breeder materials in a component known as a Helium Cooled Breeder Blanket (HCPB),for the production of tritium. The HCPB breeding blanket constitutes a key component of the ITER reactor design. In such reactor designs tritium is produced by neutrons leaving the plasma and interacting with lithium in the blanket.Li2TiO3 along with Li4SiO4 are attractive as tritium breeding materials because they exhibit high tritium release, low activation, and chemical stability.[10]

Lithium titanate aerogel[edit]

In order to advance the lithium ion battery, lithium titanate aerogel (of composition Li4Ti5O12) is currently being investigated as an effective anode material.[11]

See also[edit]

References[edit]

  1. ^ van der Laan, J. . & Muis, R. . Properties of lithium metatitanate pebbles produced by a wet process. Journal of Nuclear Materials 271-272, 401–404 (1999).
  2. ^ "Lithium Titanate Fact Sheet". Product Code: LI2TI03. Thermograde. Retrieved 24 June 2010. 
  3. ^ Vijayakumar M.; Kerisit, S.; Yang, Z.; Graff, G. L.; Liu, J.; Sears, J. A.; Burton, S. D.; Rosso, K. M.; Hu, J. (2009). "Combined 6,7Li NMR and Molecular Dynamics Study of Li Diffusion in Li2TiO3". Journal of Physical Chemistry 113: 20108–20116. doi:10.1021/jp9072125. 
  4. ^ http://www.merriam-webster.com/dictionary/monoclinic (accessed April 13, 2012).
  5. ^ Kleykamp, H (2002). "Phase equilibria in the Li–Ti–O system and physical properties of Li2TiO3". Fusion Engineering and Design. 61: 361–366. 
  6. ^ Laumann, Andreas; Jensen, Ørnsbjerg; Kirsten, Marie; Tyrsted, Christoffer (2011). "In‐situ Synchrotron X‐ray Diffraction Study of the Formation of Cubic Li2TiO3 Under Hydrothermal Conditions". Eur. J. of Inorg. Chem. 14: 2221–2226. doi:10.1002/ejic.201001133. 
  7. ^ Sahu, B. S; Bhatacharyya, S.; Chaudhuri, P.; Mazumder, R., "Synthesis and sintering of nanosize Li2TiO3 ceramic breeder powder prepared by autocombustion technique"; Department of Ceramic Engineering; National Institute of Technology, Rourkela-769008; TBM Division, Institute of Plasma Research, Bhat, Gandhinagar-382428 http://dspace.nitrkl.ac.in/dspace/bitstream/2080/1139/1/INSAC2009+(A103).pdf (accessed April 13, 2012).
  8. ^ "EPO: European Patent" http://www.wipo.int/patentscope/search/en/detail.jsf?docId=WO1996015561&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCT+Biblio (accessed April 13, 2012).
  9. ^ Ehingen, A. P.; Feldkirchen, M. B.; Ulm, B. R.; Plochingen, V. P. Friedrichshafen, DE "Double layer cathode for molten carbonate fuel cells and method for producing the same." US Patent 6,420,062, July 16, 2002
  10. ^ Hanaor, D.A.H.; Kolb, M.H.H.; Gan, Y.; Kamlah, M.; Knitter, R. (2014). "Solution based synthesis of mixed-phase materials in the Li2TiO3-Li4SiO4 system". Journal of Nuclear Materials 456: 151–161. doi:10.1016/j.jnucmat.2014.09.028. 
  11. ^ Maloney,R. P.; Kim,H. J.; Sakamoto, J. S. "Lithium titanate aerogel for advanced lithium-ion batteries"; Department of Chemical Engineering and Materials Science, Michigan State University; http://pubs.acs.org/doi/pdf/10.1021/am3002742 (accessed April 13, 2012).