title: Negating interfacial impedance in garnet-based solid-state Li metal batteries.
abstract: Garnet-type solid-state electrolytes have attracted extensive attention due to their high ionic conductivity, approaching 1 mS cm-1, excellent environmental stability, and wide electrochemical stability window, from lithium metal to ∼6 V. However, to date, there has been little success in the development of high-performance solid-state batteries using these exceptional materials, the major challenge being the high solid-solid interfacial impedance between the garnet electrolyte and electrode materials. In this work, we effectively address the large interfacial impedance between a lithium metal anode and the garnet electrolyte using ultrathin aluminium oxide (Al2O3) by atomic layer deposition. Li7La2.75Ca0.25Zr1.75Nb0.25O12(LLCZN) is the garnet composition of choice in this work due to its reduced sintering temperature and increased lithium ion conductivity. A significant decrease of interfacial impedance, from 1,710 Ω cm2to 1 Ω cm2, was observed at room temperature, effectively negating the lithium metal/garnet interfacial impedance. Experimental and computational results reveal that the oxide coating enables wetting of metallic lithium in contact with the garnet electrolyte surface and the lithiated-alumina interface allows effective lithium ion transport between the lithium metal anode and garnet electrolyte. We also demonstrate a working cell with a lithium metal anode, garnet electrolyte and a high-voltage cathode by applying the newly developed interface chemistry.
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Han
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Gong
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Kun Kelvin
authors.initials: KK
authors.lastname: Fu
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Xingfeng
authors.initials: X
authors.lastname: He
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Hitz
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Dai
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.|Institute for Systems Research, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Pearse
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Boyang
authors.initials: B
authors.lastname: Liu
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Howard
authors.initials: H
authors.lastname: Wang
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.|Institute for Systems Research, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Rubloff
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Yifei
authors.identifier: 0000-0002-8162-4629
authors.initials: Y
authors.lastname: Mo
authors.affiliation: Department of Chemistry, University of Calgary, 2500 University Drive Northwest, Calgary, Alberta T2N 1N4, Canada.
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Thangadurai
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Wachsman
authors.affiliation: University of Maryland Energy Research Center, and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Liangbing
authors.initials: L
authors.lastname: Hu