title: Ultrathin two-dimensional atomic crystals as stable interfacial layer for improvement of lithium metal anode.
abstract: Stable cycling of lithium metal anode is challenging due to the dendritic lithium formation and high chemical reactivity of lithium with electrolyte and nearly all the materials. Here, we demonstrate a promising novel electrode design by growing two-dimensional (2D) atomic crystal layers including hexagonal boron nitride (h-BN) and graphene directly on Cu metal current collectors. Lithium ions were able to penetrate through the point and line defects of the 2D layers during the electrochemical deposition, leading to sandwiched lithium metal between ultrathin 2D layers and Cu. The 2D layers afford an excellent interfacial protection of Li metal due to their remarkable chemical stability as well as mechanical strength and flexibility, resulting from the strong intralayer bonds and ultrathin thickness. Smooth Li metal deposition without dendritic and mossy Li formation was realized. We showed stable cycling over 50 cycles with Coulombic efficiency ∼97% in organic carbonate electrolyte with current density and areal capacity up to the practical value of 2.0 mA/cm(2)and 5.0 mAh/cm(2), respectively, which is a significant improvement over the unprotected electrodes in the same electrolyte.
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemical Engineering, §Department of Applied Physics, and ∥Department of Physics, Stanford University , Stanford, California 94305 United States.
authors.forename: Kai
authors.initials: K
authors.lastname: Yan
authors.forename: Hyun-Wook
authors.initials: HW
authors.lastname: Lee
authors.forename: Teng
authors.initials: T
authors.lastname: Gao
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Zheng
authors.forename: Hongbin
authors.initials: H
authors.lastname: Yao
authors.forename: Haotian
authors.initials: H
authors.lastname: Wang
authors.forename: Zhenda
authors.initials: Z
authors.lastname: Lu
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liang
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu
authors.forename: Steven
authors.initials: S
authors.lastname: Chu
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: Coulombic efficiency; Lithium metal anode; boron nitride; graphene