Mechanical properties of the solid Li-ion conducting electrolyte: Li0.33La0.57TiO3
Li0.33La0.57TiO3 (LLTO) is a potential Li-ion conducting membrane for use in aqueous Li-air batteries. To be in this configuration its mechanical properties must be determined. Dense LLTO was prepared using a solid-state (SS) or sol–gel (SG) procedure and was hot-pressed to yield a high relative density material (>95 %). Young’s modulus, hardness, and fracture toughness of the LLTO-SS and sol–gel LLTO-SG materials was determined and compared to other solid Li-ion conducting electrolytes. The Young’s modulus for LLTO-SG and LLTO-SS was 186 ± 4 and 200 ± 3 GPa, respectively. The Vickers hardness of LLTO-SG and LLTO-SS was 9.7 ± 0.7 and 9.2 ± 0.2 GPa, respectively. The fracture toughness, K IC, of both LLTO-SG and LLTO-SS was ~1 MPa m1/2; the fracture toughness of LLTO-SG was slightly higher than that of LLTO-SS. Both LLTO-SG and LLTO-SS have a Young’s modulus and hardness greater than the other possible solid Li-ion conducting membranes; Li7La3Zr2O12 and Li1+x+y Al x Ti2−x Si y P3−y O12. Based on modulus and hardness hot-pressed LLTO exhibits sufficient mechanical integrity to be used as a solid Li-ion conducting membrane in aqueous Li-air batteries but, its fracture toughness needs to be improved without degrading its ionic conductivity.
KeywordsFracture Toughness Relative Density High Fracture Toughness Rockwell Hardness Lanthanum Nitrate
This study was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology (2009-0093814) and the National Research Foundation of Korea Grant (KRF-2008-313-D00012). JW would like to acknowledge the support of the U.S. Army Research Laboratory (ARL). Authors JS, ER and HK would like to acknowledge support from the Army Research Office (ARO).
- 2.Bruce PG, Freunberger SA, Hardwick LJ, Tarascon J-M (2012) Nature Mater 11:19Google Scholar
- 5.Thangadurai V, Weppner W (2006) Solid State Ionics 12:81Google Scholar
- 21.Miyoshi T (1985) J Jpn Soc Mech 51:2489Google Scholar
- 25.Hutchinson JW (1989) In: Germain P, Piau M, Caillerie D (eds) Theoretical and applied mechanics. Elsevier, Amsterdam, pp 139–144Google Scholar
- 27.Barsoum MV (1997) Fundamentals of ceramics. The McGraw-Hill Companies, Inc., New YorkGoogle Scholar
- 40.Ni JE, Case ED, Sakamoto J, Ranagasamy E, Wolfenstine (2012) J Mater Sci (submitted)Google Scholar
- 41.Kingery WD, Bowen HK, Uhlmann DR (1976) Introduction to ceramics, 2nd edn. Wiley, New YorkGoogle Scholar
- 43.Chiang YM, Birnie D, Kingery WD (1979) Physical ceramics. Wiley, New YorkGoogle Scholar
- 45.Chin GY, Wernick JH, Geballe TG, Mahajan S, Nakahara S (1978) J Appl Phys 33:103Google Scholar
- 46.Barrett CR, Nix WD, Tetelman AS (1973) The principles of engineering materials. Prentice-Hall, Inc., Englewood Cliffs, NJGoogle Scholar
- 48.Faber KT, Evans AG (1983) Acta Metall 4:565Google Scholar
- 49.Faber KT, Evans AG (1983) Acta Metall 4:577Google Scholar