安全な全固体電池の開発に向けた電解質材料の新たな知見 (Unlocking safer batteries: New study uncovers key insights into electrolyte materials for all-solid-state batteries)

2025-02-10 アルゴンヌ国立研究所 (ANL)

＜関連情報＞

• https://www.anl.gov/article/unlocking-safer-batteries-new-study-uncovers-key-insights-into-electrolyte-materials-for
• https://pubs.acs.org/doi/10.1021/acsmaterialslett.4c01237

AlおよびGaドープガーネット固体電解質とLi金属界面における反応性の比較解析 Comparative Analysis of Reactivity of Al and Ga Doped Garnet Solid State Electrolyte at the Interface with Li Metal

Matthew Klenk,Neelima Paul,Michael J. Counihan,Zachary D. Hood,Yisi Zhu,Justin G. Connell,Charles Hervoches,Ralph Gilles,Jeff Sakamoto,Sanja Tepavcevic,Peter Zapol,,
ACS Materials Letters  Published: October 28, 2024
DOI:https://doi.org/10.1021/acsmaterialslett.4c01237

Abstract

Lithium garnet (Li₇La₃Zr₂O₁₂, LLZO) based solid electrolytes are leading candidate materials for all-solid-state batteries with lithium metal anodes because of their high ionic conductivity, high mechanical toughness, and superior electrochemical stability. While doping LLZO with Al and Ga increases its ionic conductivity by stabilizing the cubic phase, the impact of dopants on its (electro)chemical stability at the interfaces with Li metal is critical. Our study of differences between Al- and Ga-doped LLZO when interfaced with lithium metal using X-ray photoelectron spectroscopy and density functional theory shows a higher propensity of Ga to move across LLZO interface with Li metal and form Ga–Li alloy. Neutron diffraction reveals loss of cubic phase resulting from the loss of dopant that explains electrochemical behavior differences between Ga- and Al-doped LLZO. Overall, our study reveals the key role of dopant chemistry in enabling stable solid electrolyte materials for all-solid-state batteries.