Issue 9, 2021

Capacity and phase stability of metal-substituted α-Ni(OH)2 nanosheets in aqueous Ni–Zn batteries

Abstract

Batteries that offer high specific energy and energy density coupled with improved safety and lower cost will affect applications ranging from electric vehicles, portable electronic devices, and grid-level energy storage. Alkaline nickel–zinc (Ni–Zn) batteries use nonflammable aqueous electrolyte and nonstrategic, low-cost electrode materials; however with a two-electron anode, a cathode that stores more than one electron per Ni atom would increase energy density. Herein, we report the effect of substituting metal ions (aluminium, cobalt, manganese, or zinc) into α-Ni(OH)2, a phase that can accommodate more than one-electron charge storage, but which typically converts to lower-capacity β-Ni(OH)2 upon cycling in alkaline electrolytes. We adapt a microwave-assisted process that expresses α-Ni(OH)2 as a high surface-area nanosheet morphology and find that we retain this morphology with all metal-ion substituents. The series is characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Metal-ion substitution influences aggregate growth, interlayer distance, and vibrational frequencies. We test powder-composite cathodes prepared using the substituted α-Ni(OH)2 series versus zinc sponge anodes in alkaline electrolyte under device-relevant mass loadings and using an intentionally aggressive charging protocol to determine onset voltage for oxygen evolution. The electrochemical charge-storage behaviour is established using galvanostatic cycling and differential capacity analysis. The substituents significantly influence both Ni-centred redox and oxygen-evolution voltages (vs. Zn/Zn2+). The incorporation of Al3+ within α-Ni(OH)2 nanosheets provides higher capacity and phase stability compared to the divalent substituents and unsubstituted α-Ni(OH)2. The presence of ordered free nitrates in the interlayer of Al3+-substituted α-Ni(OH)2, not seen with Co2+ or Mn2+ substituents, correlates with the improved electrochemical performance.

Graphical abstract: Capacity and phase stability of metal-substituted α-Ni(OH)2 nanosheets in aqueous Ni–Zn batteries

Supplementary files

Article information

Article type
Paper
Submitted
28 yan 2021
Accepted
25 mar 2021
First published
25 mar 2021
This article is Open Access
Creative Commons BY-NC license

Mater. Adv., 2021,2, 3060-3074

Capacity and phase stability of metal-substituted α-Ni(OH)2 nanosheets in aqueous Ni–Zn batteries

S. W. Kimmel, B. J. Hopkins, C. N. Chervin, N. L. Skeele, J. S. Ko, R. H. DeBlock, J. W. Long, J. F. Parker, B. M. Hudak, R. M. Stroud, D. R. Rolison and C. P. Rhodes, Mater. Adv., 2021, 2, 3060 DOI: 10.1039/D1MA00080B

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements