Разработана методика жидкофазного синтеза титаната лития состава Li4Ti5O12 с использованием тетрахлорида титана и гидрооксида лития в качестве исходных компонентов. Для исключения затруднений, связанных с бурным, трудноконтролируемым взаимодействием тетрахлорида титана с водой, использована операция предварительного растворения тетрахлорида титана в этиленгликоле. Проведены исследования полученных образцов Li4Ti5O12 методами рентгеноструктурного анализа, микроструктурного анализа и сканирующей электронной микроскопии. В составе полупродуктов синтеза обнаружены примеси хлора, не удаляемые промывкой. Электрохимическое поведение и активность полученного электродного материала изучены на макетах литий-ионных аккумуляторов. Показана взаимосвязь электрохимических свойств полученного продукта со временем синтеза, а аномально высокая ёмкость первого цикла заряда-разряда связана электрохимически активными примесями, не способными к обратимому заряду и разряду.
Lithium-ion batteries are attracting plenty of attention nowadays. Li4Ti5O12 is one of the promising anode materials, featuring high energy efficiency, long cycle life and low cost. A new wet synthesis of Li4Ti5O12 using TiCl4 and LiOH precursors is investigated in this study. To eliminate difficulties associated with vigorous reaction of TiCl4 with water, ethylene glycol medium is used. X-ray diffractometry, microstructural analysis and scanning electron microscopy are used to investigate physical properties of acquired material. Electrochemical performance of Li4Ti5O12 is investigated using galvanostatic cycling with potential limitation of CR2032 test cells with lithium counter electrode. It is shown in the study, that 24 hours of boiling of the precursors in ethylene glycol and 3 hours of firing at 500°C is enough to acquire Li4Ti5O12 with particle size less than 100nm. Increasing synthesis time does not lead to better performance, but, on the contrary, decreases discharge capacity and purity of Li4Ti5O12. It is shown, that traces of Cl-ion were present in the intermediate product of the long synthesis, which were not removed by washing with water. High discharge capacity (>200mAh/g) acquired on the first discharge cycle is associated with TiO2 impurity, which become electrochemically inactive on the second discharge cycle.
1. Arico A.S. Nanostructured materials for advanced energy conversion and storage devices / A.S. Arico, P. Bruce, B. Scrosati et al. // Nature Materials. - 2005. - Vol. 4. - P. 366-377.
2. Pasquier A.D. Li4Ti5O12/poly(methyl)thiophene asymmetric hybrid electrochemical device / A.D. Pasquier, A. Laforgue, P. Simon // Journal of Power Sources. - 2004. - Vol. 125. - P. 95-102.
3. Guerfi A. Nano-particle Li4Ti5O12 spinel as electrode for electrochemical generators / A. Guerfi, S. Sevigny, M. Lagace et al. // Journal of Power Sources. - 2003. - Vol. 119. - P. 88-94.
4. Prosini P.P. Li4Ti5O12 as anode in all-solid-state, plastic, lithium-ion batteries for low-power applications /P.P. Prosini, R. Mancini, L. Petrucci et al. // Solid State Ionics. - 2001. - Vol. 144. - P. 185-192.
5. Sannier L. Lithium metal batteries operating at room temperature based on different PEO-PVdF separator configurations / L. Sannier, R. Bouchet, L. Santinacci, et al. // Journal of The Electrochemical Society. - 2004. - Vol. 151. - № 6. - P. A873-A879.
6. Ohzuku T. Zero-strain insertion material of Li[Lil/3Ti5/3]O4 for rechargeable lithium cells / T. Ohzuku, A. Ueda, N. Yamamota // Journal of The Electrochemical Society. - 1995. - Vol. 142. - № 5. - P. A1431-A1435.
7. Takai S. Diffusion coefficient measurement of lithium ion in sintered Li1.33Ti1.67O4 by means of neutron radiography / S. Takai, M. Kamata, S. Fujine et al. // Solid State Ionics. - 1999. - Vol. 123. - P. 165-172.
8. Aldon L. Chemical and electrochemical Li-insertion into the Li4Ti5O12 Spinel / L. Aldon, P. Kubiak, M. Womes et al. // Chemistry of Materials. - 2004. - Vol. 16. - №26. - P. 5721-5725.
9. Masatoshi M. Development of long life lithium ion battery for power storage / M. Majima, S. Ujiie, E. Yagasaki et al. // Journal of Power Sources. - 2001. - Vol. 101. - P. 53-59.
10. Wen Z. Composite anode materials for Li-ion batteries / Z. Wen, X. Yang, S. Huang // Journal of Power Sources. - 2007. - Vol. 174. - P. 1041-1045.
11. Guerfi A. Nano electronically conductive titanium-spinel as lithium ion storage negative electrode / A. Guerfi, P. Charest, K. Kinoshita et al. // Journal of Power Sources. - 2004. - Vol. 126. - P. 163-168.
12. Amatucci G.G. An asymmetric hybrid nonaqueous energy storage cell / G.G. Amatucci, F. Badway, A.D. Pasquier, T. Zheng // Journal of The Electrochemical Society. - 2001. - Vol. 148. - №8. - P. A930-A939.
13. Hao Y. Synthesis by citric acid sol-gel method and electrochemical properties of Li4Ti5O12 anode material for lithium-ion battery / Y. Hao, O. Lai, D. Liu. et al. // Materials Chemistry and Physics. - 2005. - Vol. 94. - № 2-3. - P. 382-387.
14. Hao Y. Synthesis by TEA sol-gel method and electrochemical properties of Li4Ti5O12 anode material for lithium-ion battery / Y. Hao, Q. Lai, Z. Xu et al. // Solid State Ionics. - 2005. - Vol. 176. - P. 1201-1206.
15. Hao Y. Synthesis and characterization of spinel Li4Ti5O12 anode material by oxalic acid-assisted sol-gel method / Y. Hao, Q. Lai, J. Lu et al. // Journal of Power Sources. - 2006. - Vol. 158. - P. 1358-1364.
16. Li J. Controllable formation and electrochemical properties of one-dimensional nanostructured spinel Li4Ti5O12 / J. Li, Z. Tang, Z. Zhang // Electrochemistry Communications. - 2005. - Vol. 7. - P. 894-899.
17. Kim H. Novel synthesis method and electrochemical characteristics of lithium titanium oxide as anode material for high power device / H. Kim, M. Oh, W. Son et al. // 8th international conference on properties and applications of dielectric materials : conference publications. - Bali, 2006. - P. 464-467.
18. West A.R. Solid Sate Chemistry and its Applications. - New York: John Wiley and Sons, 1984. - 742 p.