title: Dendrite-free lithium deposition with self-aligned nanorod structure.
abstract: Suppressing lithium (Li) dendrite growth is one of the most critical challenges for the development of Li metal batteries. Here, we report for the first time the growth of dendrite-free lithium films with a self-aligned and highly compacted nanorod structure when the film was deposited in the electrolyte consisting of 1.0 M LiPF6 in propylene carbonate with 0.05 M CsPF6 as an additive. Evolution of both the surface and the cross-sectional morphologies of the Li films during repeated Li deposition/stripping processes were systematically investigated. It is found that the formation of the compact Li nanorod structure is preceded by a solid electrolyte interphase (SEI) layer formed on the surface of the substrate. Electrochemical analysis indicates that an initial reduction process occurred at ∼ 2.05 V vs Li/Li(+) before Li deposition is responsible for the formation of the initial SEI, while the X-ray photoelectron spectroscopy indicates that the presence of CsPF6 additive can largely enhance the formation of LiF in this initial SEI. Hence, the smooth Li deposition in Cs(+)-containing electrolyte is the result of a synergistic effect of Cs(+) additive and preformed SEI layer. A fundamental understanding on the composition, internal structure, and evolution of Li metal films may lead to new approaches to stabilize the long-term cycling stability of Li metal and other metal anodes for energy storage applications.
authors.affiliation: Energy and Environment Directorate, ∥Environmental and Molecular Sciences Laboratory, and ⊥Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Qian
authors.forename: Wu
authors.initials: W
authors.lastname: Xu
authors.forename: Selena M
authors.initials: SM
authors.lastname: Russell
authors.forename: Xilin
authors.initials: X
authors.lastname: Chen
authors.forename: Eduard
authors.initials: E
authors.lastname: Nasybulin
authors.forename: Priyanka
authors.initials: P
authors.lastname: Bhattacharya
authors.forename: Mark H
authors.initials: MH
authors.lastname: Engelhard
authors.forename: Donghai
authors.initials: D
authors.lastname: Mei
authors.forename: Ruiguo
authors.initials: R
authors.lastname: Cao
authors.forename: Fei
authors.initials: F
authors.lastname: Ding
authors.forename: Arthur V
authors.initials: AV
authors.lastname: Cresce
authors.forename: Kang
authors.initials: K
authors.lastname: Xu
authors.forename: Ji-Guang
authors.initials: JG
authors.lastname: Zhang
mesh_terms: D003460:Crystallization / Q000379:methods; D004566:Electrodes; D004595:Electroplating / Q000379:methods; D008094:Lithium / Q000737:chemistry*; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D013499:Surface Properties
chemical_list: D008094:Lithium
keywords: Electrodeposition; Li dendrite; Li nanorods; dendrite-free; surface composition