Available on-demand - *F.EN03.04.03
Lithium Metal Anodes—The Dynamic Evolution of Electrochemical, Morphological and Mechanical Phenomena
University of Michigan1
Lithium (Li) metal anodes have experienced a resurgence of research in recent years, which has been fueled by advances in electrolyte chemistry (both solid and liquid), interfacial engineering, and rational design of electrode architectures1,2. This has enabled Coulombic efficiency values to push above 99.5%, and cycle life to extend into relevant ranges for transportation applications3. However, while performance metrics are beginning to approach relevant values for consideration of their use in electric vehicles, several fundamental questions remain on how Li metal anodes dynamically evolve during cycling, especially at high current densities. Towards this goal, there is a continued need for new methods to quantitatively measure the evolving morphology, mechanical response, and electrochemical overpotentials of Li metal anodes under realistic conditions.
In this talk, I will discuss recent insights that have been gained on how morphological evolution of non-planar geometries couple with mechanical stresses, both during both electrodeposition and dissolution4. To contextualize the critical role of coupled electro-chemo-mechanical phenomena, examples of dynamic Li metal deformation will be discussed during cycling in solid and liquid electrolytes. Specifically, a multi-modal suite of operando analytical techniques will be employed to describe the role of mechanical stresses during the formation of “dead” Li, crack propagation in ceramic solid electrolytes during high-rate cycling, and reversible cycling of Li metal to achieve high Coulombic efficiencies5–8.
To compliment the cross-sectional perspective provided in our previous operando optical microscopy investigations, recent cell designs that enable plan-view operando of Li metal dynamics will be demonstrated for both liquid and solid electrolyte systems. In liquid electrolytes this allows for new insight into the influence of surface microstructure on nucleation of both dendrites and pits, and the critical role of surface heterogeneity on Coulombic efficiency9. In solid electrolytes, plan-view imaging enables direct visualization of Li metal filament propagation in garnet LLZO ceramics, and four distinct filament morphologies are identified10. Equipped with this fundamental understanding, the talk will aim to address the following critical question in the field: how, when, where, and why does “dead” Li form, and can we control this irreversible Li loss during battery operation?
(1) Wood, K. N.; Noked, M.; Dasgupta, N. P. ACS Energy Lett. 2017, 2 (3), 664–672.
(2) Hatzell, K. B. et al. ACS Energy Letters. 2020, 5, 922–934.
(3) Chen, K.-H.; Sanchez, A. J.; Kazyak, E.; Davis, A. L.; Dasgupta, N. P. Adv. Energy Mater. 2019, 9 (4), 1802534.
(4) LePage, W. S.; Chen, Y.; Kazyak, E.; Chen, K.-H.; Sanchez, A. J.; Poli, A.; Arruda, E. M.; Thouless, M. D.; Dasgupta, N. P. J. Electrochem. Soc. 2019, 166 (2), A89–A97.
(5) Wood, K. N.; Kazyak, E.; Chadwick, A. F.; Chen, K.-H.; Zhang, J.-G.; Thornton, K.; Dasgupta, N. P. ACS Cent. Sci. 2016, 2 (11).
(6) Chen, K.-H.; Wood, K. N.; Kazyak, E.; LePage, W. S.; Davis, A. L.; Sanchez, A. J.; Dasgupta, N. P. J. Mater. Chem. A 2017, 5 (23), 11671–11681.
(7) Gupta, A.; Kazyak, E.; Craig, N.; Christensen, J.; Dasgupta, N. P.; Sakamoto, J. J. Electrochem. Soc. 2018, 165 (11), A2801–A2806.
(8) Davis, A. L.; Kazyak, E.; Sakamoto, J.; Dasgupta, N. P.; Garcia-Mendez, R.; Chen, K. H.; Sakamoto, J.; Wood, K. N.; Teeter, G.; Wood, K. N. J. Mater. Chem. A 2020, 8 (13), 6291–6302.
(9) Sanchez, A. J.; Kazyak, E.; Chen, Y.; Chen, K. H.; Pattison, E. R.; Dasgupta, N. P. ACS Energy Lett. 2020, 5 (3), 994–1004.
(10) Kazyak, E.; Garcia-Mendez, R.; LePage, W. S.; Sharafi, A.; Davis, A. L.; Sanchez, A. J.; Chen, K. H.; Haslam, C.; Sakamoto, J.; Dasgupta, N. P. Matter 2020, 2 (4), 1025–1048.