Cubic garnet solid polymer electrolyte for room temperature operable all-solid-state-battery

• Published in: Journal of materials research and technology Vol. 15; pp. 5849 - 5863
• Main Authors: Luu, Van Tung, Nguyen, Quoc Hung, Park, Moon Gyu, Nguyen, Hoang Long, Seo, Min-Ho, Jeong, Soon-Ki, Cho, Namchul, Lee, Young-Woo, Cho, Younghyun, Lim, Sung Nam, Jun, Yun-Seok, Ahn, Wook
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2021; Elsevier
• Subjects: All-solid-state; Cubic garnet llzo; Lithium-ion battery; Solid polymer electrolytes; Succinonitrile; Lithium-ion battery; All-solid-state; Succinonitrile; Solid polymer electrolytes; Cubic garnet llzo
• ISSN: 2238-7854
• DOI: 10.1016/j.jmrt.2021.11.055

Solid polymer electrolytes are promising candidates for implementation in next-generation all-solid-state batteries (ASSBs) which could replace conventional batteries used today. However, the materialization of ASSBs on a mass scale is restricted by the low ionic conductivity and high interfacial resistance of solid electrolytes. In this work, succinonitrile (SN) with lithium (trifluoromethylsulphonyl)imide (LiTFSI) and Al-doped Li7La3Zr2O12 (Al-LLZO) nanoparticles were used to improve the ionic conductivity of a polyethylene oxide-based composite electrolyte. The Al-LLZO nanoparticles were synthesized by a facile synthesis process at low temperatures, which contributed to an enhancement in the ionic conductivity. A solid polymer electrolyte with 7.5 wt% of Al-LLZO and 15 wt% of SN achieved a high ionic conductivity of 4.17 × 10−4 Scm−1 at room temperature and a large value of 0.451 for the lithium-ion transport number at 60 °C. By adding 10 wt% SN and 10 wt% of Al-LLZO in the LiFePO4 cathode, the cell could operate at 25 °C with a specific capacity of 130 mAh g−1 and 89% capacity retention after 200 cycles at current density of 20 mA g−1. This study therefore proposes a solution to improve the ionic conductivity of solid polymer electrolytes in all-solid-state batteries.