Design of Preferentially Faceted Zinc to Improve the Rechargeability of Alkaline Batteries

Abstract

Rechargeable Zinc-based batteries have attracted a growing interest due to their intrinsic high safety as well as the low environmental impact and low cost of Zinc. However, there still exists some major obstacles in achieving these low cost secondary cells, including shape change during repeated charge/discharge (dendrite formation) and limited reversibility of the Zinc electrodes. Traditional Zinc anodes are formed from large, polycrystalline particles with limited control over the morphology. Many studies have looked to improve morphology control of Zinc through the design of Zinc nanostructures 1, 2, but the future implementation of these nanomaterials is hindered by the high rate of corrosion for Zinc nanostructures 3, 4 as well as the expense and scalability of manufacturing such nanostructures. Therefore, there is a need to develop a scalable synthesis method that allows for the creation of large monocrystalline particles with controlled shape. In this work, we report a facile electrolytic method to synthesize micron-sized preferentially faceted, hexagonal-shaped Zinc particles. Using a three-electrode electrochemical cell, the charge and discharge behavior of these Zinc particles were studied in alkaline (6M KOH) and mildly acidic (1M ZnSO4) aqueous electrolytes. It was confirmed that the dendrites form during cycling the Zinc particles in KOH electrolytes, however, using ZnSO4 electrolytes no dendrite formation was observed, and the particles were able to retain their hexagonal structures ever after cycling for than 100 times at 1C. References M. Chamoun, B. J. Hertzberg, T. Gupta, D. Davies, S. Bhadra, B. Van Tassell, C. Erdonmez, and D. A. Steingart, NPG Asia Materials, 7 (4), e178 (2015).T.-H. Wu, Y. Zhang, Z. D. Althouse, and N. Liu, Materials Today Nano, 100032 (2019).E. Faegh, T. Omasta, M. Hull, S. Ferrin, S. Shrestha, J. Lechman, D. Bolintineanu, M. Zuraw, and W. E. Mustain, Journal of The Electrochemical Society, 165 (11), A2528-A2535 (2018).Y.-D. Cho and G. T.-K. Fey, Journal of Power Sources, 184 (2), 610-616 (2008).