Transient Polarization and Dendrite Initiation Dynamics in Ceramic Electrolytes

Fuente: arXiv
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Main Authors: Gopal, Rajeev, Wu, Longan, Lee, Youngju, Guo, Jinzhao, Bai, Peng
Format: Preprint
Published: 2021
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author Gopal, Rajeev
Wu, Longan
Lee, Youngju
Guo, Jinzhao
Bai, Peng
author_facet Gopal, Rajeev
Wu, Longan
Lee, Youngju
Guo, Jinzhao
Bai, Peng
contents Solid-state electrolytes, by enabling lithium metal anodes, may significantly increase the energy density of current lithium-ion batteries. However, similar to their liquid counterparts, these hard and stiff electrolytes can still be penetrated by soft Li metal, above a critical current density (CCD). The prevailing method to determine the CCD employs step-wise galvanostatic cycling, which suffers from inconsistent active interfacial areas due to void formations after repeated stripping and plating, leaving large variance in the reported data that preclude precision understandings. Here, we combine a one-way polarization technique with electrochemical impedance spectroscopy to uncover, for the first time, the existence of significant polarization dynamics in ceramic electrolytes. In contrast to the diverging transient current due to metal penetration, the current peaks we observed suggest a diffusion-limited mechanism that follows the classic Randles-Sevcik equation for analyzing the diffusion-limited processes in liquid electrolytes. Our results allow a rigorous self-consistent analysis to reveal that the CCD is a diffusion-limited current density, while the system-specific limiting current density for ceramic electrolytes is still lower than CCD, which suggests that the ion transport mechanism preceding the dendrite penetration in ceramic electrolytes is unifiable with that in liquid electrolytes.
format Preprint
id arxiv_https___arxiv_org_abs_2110_13399
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Transient Polarization and Dendrite Initiation Dynamics in Ceramic Electrolytes
Gopal, Rajeev
Wu, Longan
Lee, Youngju
Guo, Jinzhao
Bai, Peng
Chemical Physics
Applied Physics
Solid-state electrolytes, by enabling lithium metal anodes, may significantly increase the energy density of current lithium-ion batteries. However, similar to their liquid counterparts, these hard and stiff electrolytes can still be penetrated by soft Li metal, above a critical current density (CCD). The prevailing method to determine the CCD employs step-wise galvanostatic cycling, which suffers from inconsistent active interfacial areas due to void formations after repeated stripping and plating, leaving large variance in the reported data that preclude precision understandings. Here, we combine a one-way polarization technique with electrochemical impedance spectroscopy to uncover, for the first time, the existence of significant polarization dynamics in ceramic electrolytes. In contrast to the diverging transient current due to metal penetration, the current peaks we observed suggest a diffusion-limited mechanism that follows the classic Randles-Sevcik equation for analyzing the diffusion-limited processes in liquid electrolytes. Our results allow a rigorous self-consistent analysis to reveal that the CCD is a diffusion-limited current density, while the system-specific limiting current density for ceramic electrolytes is still lower than CCD, which suggests that the ion transport mechanism preceding the dendrite penetration in ceramic electrolytes is unifiable with that in liquid electrolytes.
title Transient Polarization and Dendrite Initiation Dynamics in Ceramic Electrolytes
topic Chemical Physics
Applied Physics
url https://arxiv.org/abs/2110.13399