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Abstract As solid‐state batteries (SSBs) with lithium (Li) metal anodes gain increasing traction as promising next‐generation energy storage systems, a fundamental understanding of coupled electro‐chemo‐mechanical interactions is essential to design stable solid‐solid interfaces. Notably, uneven electrodeposition at the Li metal/solid electrolyte (SE) interface arising from intrinsic electrochemical and mechanical heterogeneities remains a significant challenge. In this work, the thermodynamic origins of mechanics‐coupled reaction kinetics at the Li/SE interface are investigated and its implications on electrodeposition stability are unveiled. It is established that the mechanics‐driven energetic contribution to the free energy landscape of the Li deposition/dissolution redox reaction has a critical influence on the interface stability. The study presents the competing effects of mechanical and electrical overpotential on the reaction distribution, and demarcates the regimes under which stress interactions can be tailored to enable stable electrodeposition. It is revealed that different degrees of mechanics contribution to the forward (dissolution) and backward (deposition) reaction rates result in widely varying stability regimes, and the mechanics‐coupled kinetics scenario exhibited by the Li/SE interface is shown to depend strongly on the thermodynamic and mechanical properties of the SE. This work highlights the importance of discerning the underpinning nature of electro‐chemo‐mechanical coupling toward achieving stable solid/solid interfaces in SSBs.
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Modeling the chemo-mechanical behavior of all-solid-state batteries: a review.
Solid-state-batteries (SSBs) present a promising technology for next-generation batteries due to their superior properties including increased energy density, wider electrochemical window and safer electrolyte design. Commercialization of SSBs, however, will depend on the resolution of a number of critical chemical and mechanical stability issues. The resolution of these issues will in turn depend heavily on our ability to accurately model these systems such that appropriate material selection, microstructure design, and operational parameters may be determined. In this article we review the current state-of-the art modeling tools with a focus on chemo-mechanics. Some of the key chemo-mechanical problems in SSBs involve dendrite growth through the solid-state electrolyte (SSE), interphase formation at the anode/SSE interface, and damage/decohesion of the various phases in the solid-state composite cathode. These mechanical processes in turn lead to capacity fade, impedance increase, and short-circuit of the battery, ultimately compromising safety and reliability. The article is divided into the three natural components of an all-solid-state architecture. First, modeling efforts pertaining to Li-metal anodes and dendrite initiation and growth mechanisms are reviewed, making the transition from traditional liquid electrolyte anodes to next generation all-solid-state anodes. Second, chemo-mechanics modeling of the SSE is reviewed with a particular focus on the formation of a thermodynamically unstable interphase layer at the anode/SSE interface. Finally, we conclude with a review of chemo-mechanics modeling efforts for solid-state composite cathodes. For each of these critical areas in a SSB we conclude by highlighting the key open areas for future research as it pertains to modeling the chemo-mechanical behavior of these systems.
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- Award ID(s):
- 1825132
- PAR ID:
- 10187689
- Date Published:
- Journal Name:
- Meccanica
- ISSN:
- 0025-6455
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s11012-020-01209-y
