Lithium titanate

Lithium titanate

Names
Other names Lithium metatitanate
Identifiers
CAS Number	12031-82-2
ECHA InfoCard	100.031.586
PubChem	160968
Properties
Chemical formula	Li2TiO3
Molar mass	109.76
Appearance	Off-white powder
Density	3.43 g/cm^3 [1]
Melting point	1,533 °C (2,791 °F; 1,806 K)
Except where otherwise noted, 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

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

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

Molten carbonate fuel cells

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

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

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

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

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

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

• Lithium battery

References

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).