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This content will become publicly available on February 2, 2019

Title: Nanoscale in situ detection of nucleation and growth of Li electrodeposition at various current densities

Li metal batteries can store at least ten times more energy than currently existing Li-ion batteries. However, during routine charging and discharging, Li dendrites grow on the Li metal electrode, which can lead to capacity loss by the consumption of Li salt at the surface of the Li dendrites, and be a safety hazard resulting from the potential for short-circuits. Although past efforts have provided useful information about the morphology and surface area of Li dendrite formation at the microscale, a nanoscale understanding of nucleation and growth of Li nanoparticle electrodeposition is still elusive. In this study, using a new electrochemical cell for transmission mode grazing incidence small angle X-ray scattering, we obtained, for the first time, the primary nucleus size of Li nanoparticles, their size evolution and their fractal structures at various current densities and in real-time. The measured average radius of gyration, R g, at current densities of 0.1, 0.5, and 2.0 mA cm -2 is 5.4 ± 0.4, 4.5 ± 0.3, and 3.5 ± 0.3 nm, respectively. This variation in size with current density is noteworthy when recognizing that the surface area-to-volume ratio of the Li nanoparticles is 3.7 times higher at 2.0 mA cm -2 thanmore » at 0.1 mA cm -2. We also compared a hierarchical fractal structure of Li particles from the nanometer to micrometer scale. Our findings illuminate the role of overpotential in the reactive surface area of Li dendrites at the nanoscale, and provide a novel research platform for suppressing Li dendrite formation in Li metal battery systems.« less
Authors:
ORCiD logo [1] ; ORCiD logo [2] ;  [1] ;  [1] ;  [3] ; ORCiD logo [3] ; ORCiD logo [1]
  1. Washington Univ., St. Louis, MO (United States). Dept. of Energy, Environmental and Chemical Engineering
  2. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
  3. Seoul National Univ. (Korea, Republic of). Program in Nano Science and Technology, Graduate School of Convergence Science and Technology
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Journal of Materials Chemistry. A
Additional Journal Information:
Journal Volume: 6; Journal Issue: 11; Journal ID: ISSN 2050-7488
Publisher:
Royal Society of Chemistry
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; MRI; cells; dendrite growth; deposition; interface; ionic-liquid; lithium metal anodes; sulfur batteries
OSTI Identifier:
1460946