Theoretical Understanding of Heterogeneous Nucleation During Lithium Electrodeposition

Lithium metal anodes are required to transform the present-day Li-ion batteries for storing more energy. A key challenge is to ensure uniform electrodeposition of lithium when the cell is being charged. While most previous studies examine the efficacy of various mechanisms in regularizing an uneven interface^1,2,3, the formation of the uneven interface is poorly understood. Whenever lithium deposits on a surface other than pristine lithium, nucleation is observed⁴. Physics-based understanding of this step is essential to identify the factors that govern nucleation and cause nonuniform growth. In this talk, we propose a theoretical description of lithium nucleation and growth during electrodeposition. We show that nucleation during electrodeposition differs from the metallurgical understanding of melt solidification. We correlate such theoretical understanding with experimental observations. We discuss material property targets to tune the nonuniformity associated with the nucleation and early time growth of electrodeposited lithium.<br/><br/><b>References</b>:<br/>1. Monroe & Newman (2005) J. Electrochem. Soc. 152(2) A396, doi: 10.1149/1.1850854<br/>2. Bai, Brushett & Bazant (2016) Energy Environ. Sci. 9, 3221, doi: 10.1039/C6EE01674J<br/>3. Barai, Higa & Srinivasan (2018) J. Electroche. Soc. 165(11) A2654, doi: 10.1149/2.0651811jes<br/>4. Pei et al. (2017) ACS Nano 17(2) 1132, doi: 10.1021/acs.nanolett.6b04755