(569ct) Mechanistic Investigation into Dendrite Growth on Zinc Batteries

Zinc-based batteries are widely used for energy storage and electrochemical applications, owing to their high-energy density and abundance. However, their long-term operation is hindered due to the formation and growth of dendrite structures on the anodic surface, primarily under alkaline electrolytic conditions^1–3_. The mechanism behind the appearance of these structures has been studied in detail^1,4. Prior DFT investigations have documented facile diffusion barriers of Zn across various surface motifs ^5,6 highlighting its tendency to prefer formation of undercoordinated structures. However, current theoretical models do not present a comprehensive explanation behind the dynamics of dendritic growth ³.

In this work, we utilize Density Functional Theory (DFT) calculations to study the deposition and diffusion of Zn atoms on terrace and stepped surfaces. We integrate these results into a coordination-based model, that can evaluate the stability of different structural motifs ^7,8_. We demonstrate that Zn has low cohesive energy compared to late fcc transition metals and that it prefers to deposit at low-coordination sites, leading to the occurrence of dendritic growths (Figure 1). The diffusion barriers of Zn, estimated through Nudged-Elastic-Band (NEB) methods, also correlate with its adsorption energy in different coordination environments. These results are integrated into a kinetic Monte Carlo model which provides dynamics of Zn dendrite growth as a function of its electrodeposition rate from the electrolyte.

1. Lu et al. ChemSusChem vol. 11 3996–4006 (2018).

2. Yang et al. Advanced Materials vol. 32 (2020).

3. Khor et al. Materials Today Energy vol. 8 80–108 (2018).

4. Xu et al. Batteries vol. 8 (2022).

5. Yurkiv et al. Journal of Physical Chemistry C 124, 15730–15738 (2020).

6. Iokibe et al. Journal of Physical Chemistry C 111, 13510–13516 (2007).

7. Roling et al. Journal of Physical Chemistry C 121, 23002–23010 (2017).

8. Roling et al. Nanoscale 11, 4438–4452 (2019).