(420f) Understanding Length-Scale Dependence of Morphological Instability in Electrodeposition Processes

Advances in the basic science and engineering principles of electrochemical energy storage is imperative for significant progress in portable electronic devices. In this regard, metal batteries based on a reactive metal (like Li, Na) as anode have attracted remarkable attention due to their promise of improving the gravimetric energy density by at least 3-folds, compared to the current Li-ion battery that uses graphitic anode. However, a persistent challenge with metal batteries is their propensity to fail by short-circuiting due to dendrite growth, and by runaway of cell resistance because of internal side reactions. In this talk, I will discuss my research that utilizes multiscale transport modeling and experiments to fundamentally understand and thereby develop rational designs for polymer electrolytes and electrochemical interfaces to overcome these challenges. Specifically, we utilized linear stability analysis of metal electrodeposition and showed that the length-scale on which transport occurs near the electrodes can be as important as electrolyte modulus in stabilizing metal deposition. To evaluate this concept, we designed cross-linked polymer electrolytes with tunable nanostructure and quantified corresponding dendritic growth. Direct visualization of electrodeposition using optical microscopy showed remarkable agreement with the theoretical predictions.

References:

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2. Tikekar, M. D., Choudhury, S., Tu, Z. & Archer, L. A. Design principles for electrolytes and interfaces for stable lithium-metal batteries. Nat. Energy 1, 16114 (2016).
3. Tikekar, M. D., Archer, L. A. & Koch, D. L. Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions. Sci. Adv. 2, (2016).
4. Choudhury, S. et al. Confining electrodeposition of metals in structured electrolytes. Proc. Natl. Acad. Sci. 201803385, (2018).