Journal Article

The early-stage growth and reversibility of Li electrodeposition in Br-rich electrolytes

Stalin, Sanjuna, Moon, Taylor, Zhao, Qing, Biswal, Prayag, Kludze, Atsu, Deng, Yue, Rodrigues, Joshua, Archer, Lynden A., Yin, Jiefu, Kourkoutis, Lena F.

2021

Overview

The physiochemical nature of reactive metal electrodeposits during the early stages of electrodeposition is rarely studied but known to play an important role in determining the electrochemical stability and reversibility of electrochemical cells that utilize reactive metals as anodes. We investigated the early-stage growth dynamics and reversibility of electrodeposited lithium in liquid electrolytes infused with brominated additives. On the basis of equilibrium theories, we hypothesize that by regulating the surface energetics and surface ion/adatom transport characteristics of the interphases formed on Li, Br-rich electrolytes alter the morphology of early-stage Li electrodeposits; enabling late-stage control of growth and high electrode reversibility. A combination of scanning electron microscopy (SEM), image analysis, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and contact angle goniometry are employed to evaluate this hypothesis by examining the physical–chemical features of the material phases formed on Li. We report that it is possible to achieve fine control of the early-stage Li electrodeposit morphology through tuning of surface energetic and ion diffusion properties of interphases formed on Li. This control is shown further to translate to better control of Li electrodeposit morphology and high electrochemical reversibility during deep cycling of the Li metal anode. Our results show that understanding and eliminating morphological and chemical instabilities in the initial stages of Li electroplating via deliberately modifying energetics of the solid electrolyte interphase (SEI) is a feasible approach in realization of deeply cyclable reactive metal batteries.

• Publisher: National Academy of Sciences,Proceedings of the National Academy of Sciences
• Subject: Adatoms / Additives / Anodes / Bromination / CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS / Contact angle / Electrochemical cells / Electrochemical impedance spectroscopy / Electrochemistry / Electrodeposition / Electrolytes / Electrolytic cells / Electroplating / ENERGY STORAGE / Engineering / Image analysis / Image processing / INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY / interfacial energy / Ion diffusion / Lithium / lithium metal anode / MATERIALS SCIENCE / Metals / Morphology / nucleation and growth / Photoelectron spectroscopy / Photoelectrons / Physical Sciences / Physiochemistry / Scanning electron microscopy / Science & Technology - Other Topics / solid electrolyte interphase / Solid electrolytes / Spectroscopy / Spectrum analysis / surface ion diffusion / Transport properties / X ray photoelectron spectroscopy