1. Shape matters: Understanding the effect of electrode geometry on cell resistance and chemo-mechanical stress
- Author
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Lin, Tiras Y., Li, Hanyu, Brady, Nicholas W., Cross, Nicholas R., Ehlinger, Victoria M., Roy, Thomas, Tortorelli, Daniel, Orme, Christine, Worsley, Marcus A., and Bucci, Giovanna
- Subjects
Physics - Chemical Physics - Abstract
Rechargeable batteries that incorporate shaped three-dimensional electrodes have been shown to have increased power and energy densities for a given footprint area when compared to a conventional geometry, i.e., a planar cathode and anode that sandwich an electrolyte. Electrodes can be shaped to enable a higher loading of active material, while keeping the ion transport distance small, however, the relationship between electrical and mechanical performance remains poorly understood. A variety of electrode shapes have been explored, where the electrodes are individually shaped or intertwined with one another. Advances in manufacturing and shape and topology optimization have made such designs a reality. In this paper, we explore sinusoidal half cells and interdigitated full cells. First, we use a simple electrostatics model to understand the cell resistance as a function of shape. We focus on low-temperature conditions, where the electrolyte conductivity decreases and the governing dimensionless parameters change. Next, we use a chemo-mechanics model to examine the stress concentrations that arise due to intercalation-driven volume expansion. We show that shaped electrodes provide a significant reduction in resistance, however, they result in unfavorable stress concentrations. Overall, we find that the fully interdigitated electrodes may provide the best balance with respect to this trade-off.
- Published
- 2024
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