Muons penetrate much further than X-rays, they do essentially zero damage, and they are provided for free by the cosmos.
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Edited by Alexis T. Bell, University of California, Berkeley, CA, and approved September 9, 2020 (received for review May 8, 2020)
Significance
Lithium metal anodes offer a promising approach to improve the energy density of batteries to enable electrification of transportation. Dendrite suppression plagues the safety and cycle life of lithium metal anodes. In this work, we perform a comprehensive analysis of the use of liquid crystalline electrolytes in lithium metal anodes. We report theoretical demonstration of spontaneous stabilization of metal-electrode position using a liquid crystalline electrolyte due to the energy that arises when the molecules of the liquid crystal reorient. Building on this, we develop a comprehensive set of molecular-level design rules that will pave the way toward the realization of this new class of electrolytes for practical lithium metal batteries.
Abstract
Dendrite-free electrodeposition of lithium metal is necessary for the adoption of high energy-density rechargeable lithium metal batteries. Here, we demonstrate a mechanism of using a liquid crystalline electrolyte to suppress dendrite growth with a lithium metal anode. A nematic liquid crystalline electrolyte modifies the kinetics of electrodeposition by introducing additional overpotential due to its bulk-distortion and anchoring free energy. By extending the phase-field model, we simulate the morphological evolution of the metal anode and explore the role of bulk-distortion and anchoring strengths on the electrodeposition process. We find that adsorption energy of liquid crystalline molecules on a lithium surface can be a good descriptor for the anchoring energy and obtain it using first-principles density functional theory calculations. Unlike other extrinsic mechanisms, we find that liquid crystals with high anchoring strengths can ensure smooth electrodeposition of lithium metal, thus paving the way for practical applications in rechargeable batteries based on metal anodes.
Footnotes
- ↵1To whom correspondence may be addressed. Email: venkvis{at}cmu.edu.
Author contributions: Z.A. and V.V. designed research; Z.A. performed research; Z.A. and Z.H. contributed new reagents/analytic tools; Z.A. analyzed data; and Z.A., Z.H., and V.V. wrote the paper.
The authors declare no competing interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.2008841117/-/DCSupplemental.
Data Availability.
The code for reproducing the simulations and data that support the findings are available on GitHub (https://github.com/battmodels/electrodep) (106). Raw data are available upon request.
Published under the PNAS license.
Design rules for liquid crystalline electrolytes for enabling dendrite-free lithium metal batteries
Article Classifications
- Physical Sciences
- Engineering
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