Summary
Lithium lanthanum zirconium oxide (LLZO, Li7La3Zr2O12) or lithium lanthanum zirconate is a lithium-stuffed garnet material that is under investigation for its use in solid-state electrolytes in lithium-based battery technologies.[1][2] LLZO has a high ionic conductivity and thermal and chemical stability against reactions with prospective electrode materials, mainly lithium metal, giving it an advantage for use as an electrolyte in solid-state batteries.[3] LLZO exhibits favorable characteristics, including the accessibility of starting materials, cost-effectiveness, and straightforward preparation and densification processes. These attributes position this zirconium-containing lithium garnet as a promising solid electrolyte for all-solid-state lithium-ion rechargeable batteries.
| Identifiers | |
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3D model (JSmol)
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| Properties | |
| La3Li7O12Zr2 | |
| Molar mass | 839.73 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Moreover, LLZO demonstrates a notable total conductivity, surpassing most other solid lithium-ion conductors and many lithium garnets. The fact that the total and bulk conductivities are of the same order of magnitude distinguishes LLZO garnet-type oxide as particularly attractive when compared to other ceramic lithium-ion conductors. This suggests that LLZO, with its garnet-like structure, holds significant promise for enhancing the performance of solid-state lithium-ion rechargeable batteries. [4]
Since oxygen, zirconium, and lanthanum in LLZO are rigidly bound in the framework of the garnet-like structure,[5] their mobility will be negligible at operating temperatures and, hence, the ionic motion is due to the transport of Li+ ions.
The enhanced lithium ion conductivity and reduced activation energy observed in LLZO, compared to other lithium-containing garnets, can be attributed to several factors. These include an expansion in the cubic lattice constant, an increase in lithium ion concentration, reduced chemical interactions between Li+ ions and other lattice ions, and improved densification. Even when compared to the conductivity of the relatively unstable polycrystalline Li3N at lower temperatures,[6] LLZO demonstrates comparable performance. However, at elevated temperatures, LLZO outperforms Li3N, exhibiting a higher total conductivity.
LLZO has two stable phases: the tetragonal phase and the cubic (Cubic crystal system) phase. Although the tetragonal phase can be obtained at lower synthesis temperatures than the cubic phase, the latter has higher conductivity than the former.[7] Both phases possess the same structural framework but there is a difference in the distribution of Li atoms, which dominantly determines the ionic conductivity of LLZO, Li ions have more available sites for migration in the cubic phase than in the tetragonal phase.[8] Moreover, the cubic phase LLZO is very stable in air while the tetragonal phase suffers from a phase transition occurring at around 100 – 150 °C in air.[9]
Press reports have stated that LLZO is believed to be the electrolyte used by QuantumScape for their solid-state lithium metal battery.[10]
Japanese company Niterra is working on next-generation Lithium ion battery with LLZO as electrolyte.[11]
LLZO has also been used as an electrolyte material in next-generation lithium-sulfur batteries.[12]
References edit
- ^ Yeandel, Stephen R.; Chapman, Benjamin J.; Slater, Peter R.; Goddard, Pooja (2018-12-13). "Structure and Lithium-Ion Dynamics in Fluoride-Doped Cubic Li7La3Zr2O12 (LLZO) Garnet for Li Solid-State Battery Applications". The Journal of Physical Chemistry C. 122 (49): 27811–27819. doi:10.1021/acs.jpcc.8b07704. ISSN 1932-7447. S2CID 105578102.
- ^ Tsai, Chih-Long; Ma, Qianli; Dellen, Christian; Lobe, Sandra; Vondahlen, Frank; Windmüller, Anna; Grüner, Daniel; Zheng, Hao; Uhlenbruck, Sven; Finsterbusch, Martin; Tietz, Frank (2018-12-18). "A garnet structure-based all-solid-state Li battery without interface modification: resolving incompatibility issues on positive electrodes". Sustainable Energy & Fuels. 3 (1): 280–291. doi:10.1039/C8SE00436F. ISSN 2398-4902. S2CID 139965509.
- ^ Ramakumar, S.; Deviannapoorani, C.; Dhivya, L.; Shankar, Lakshmi S.; Murugan, Ramaswamy (2017-07-01). "Lithium garnets: Synthesis, structure, Li+ conductivity, Li+ dynamics and applications". Progress in Materials Science. 88: 325–411. doi:10.1016/j.pmatsci.2017.04.007. ISSN 0079-6425.
- ^ Murugan, R.; Thangadurai, V.; Weppner, W. (2007). "Fast Lithium Ion Conduction in Garnet-Type Li7La3Zr2O12". ChemInform. 46 (41): 7778–7781. doi:10.1002/anie.200701144. PMID 17803180.
- ^ Thangadurai, V.; Adams, S.; Weppner, W. (2004-09-24). "Crystal Structure Revision and Identification of Li+-Ion Migration Pathways in the Garnet-Like Li5La3M2O12 (M: Nb, Ta) Oxides". Chemistry of Materials. 16 (41): 2998–3006. doi:10.1002/chin.200441007.
- ^ Rabenau, A. (1982). "Lithium nitride and related materials case study of the use of modern solid state research techniques". Solid State Ionics. 6 (4): 277–293. doi:10.1016/0167-2738(82)90012-1.
- ^ Tan, J.; Tiwari, A. (2011-12-28). "Synthesis of Cubic Phase Li7La3Zr2O12 Electrolyte for Solid-State Lithium-Ion Batteries". Electrochemical and Solid-State Letters. 15 (3): A37–A39. doi:10.1149/2.003203esl.
- ^ Raju, M.M.; Altayran, F.; Johnson, M.; Wang, D.; Zhang, Q (2021-07-19). "Crystal Structure and Preparation of Li7La3Zr2O12 (LLZO) Solid-State Electrolyte and Doping Impacts on the Conductivity: An Overview". Electrochem. 2 (3): 390–414. doi:10.3390/electrochem2030026.
- ^ Geiger, C.A.; Alekseev, E.; Lazic, B.; Fisch, M.; rmbruster, T.; Langner, R.; Fechtelkord, M.; Kim, N.; Pettke, T.; Weppner, W. (2010-12-28). "Crystal Chemistry and Stability of "Li7La3Zr2O12" Garnet: A Fast Lithium-Ion Conductor". Inorganic Chemistry. 50 (3): 1089–1097. doi:10.1021/ic101914e. PMID 21188978.
- ^ Temple, James (2020-12-08). "This super energy dense battery could nearly double the range of electric vehicles". MIT Technology Review. Retrieved 2020-12-08.
- ^ "Niterra". Niterra.
- ^ "Battery and Supercapacitor Materials". American Elements. Retrieved 2022-12-09.