Lithium titanate

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Lithium titanate
Identifiers
CAS number 12031-82-2 YesY
PubChem 160968
Properties
Molecular formula Li2TiO3
Appearance Off-white powder
Density 3.43 g/cm3 [1]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
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 preferred as a flux due to its stability.[2]

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 in ITER are fueled by tritium and deuterium. Tritium resources are extremely limited, currently estimated at twenty kilos. Lithium can be used as a solid breeder material of tritium in the blanket of fusion reactions in ITER. Tritium is produced by the neutrons leaving the plasma and interacting with lithium in the blanket.[10] Li2TiO3 along with Li4SiO4 are attractive as tritium breeding materials because they exhibit high tritium release, low activation, and chemical stability.[7]

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, A last2=Jensen (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. 
  7. ^ a b 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. ^ ITER Organization. http://www.iter.org/mach/tritiumbreeding (accessed April 13, 2012).
  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).