Understanding electrochemical interfaces in aluminium graphite dual‐Ion batteries
File(s)
Author(s)
Teck, Anastasia
Type
Thesis
Abstract
Rechargeable aluminium metal batteries have emerged as a compelling next generation battery technology to diversify the electrochemical energy storage market. In addition to its high theoretical capacity, aluminium benefits from high abundance and well established processing to enable low cost production and recycling. Since their first development in 2015, aluminium graphite dual‐ion batteries (AGDIBs) have gained attention for their affordable graphite cathode, non‐flammable ionic liquid electrolyte, and high power density. However, the application of this technology is limited by the chemical and electrochemical stability of cell components in the corrosive electrolyte.
This thesis seeks to improve fundamental understanding of the electrochemical interfaces in AGDIBs, focusing particularly on the anode‐electrolyte interface. While there has been significant development of cathode materials for improved energy density, little is known about the impact of corrosion and solid electrolyte interphase (SEI) formation on the aluminium electroplating mechanism in full cell AGDIBs.
Herein, the aluminium anode surface evolution was systematically studied over long cycling by ex situ and quasi‐operando techniques to elucidate the role of plating, corrosion, and SEI growth on cell performance. Electron microscopy revealed a previously unidentified degradation mechanism through inhomogeneous deposition in relation to metal contaminant reduction. X‐ray photoelectron spectroscopy and quasi‐operando soft X‐ray absorption spectroscopy in a custom cell showed the growth of the native aluminium oxide layer into an unstable SEI with the incorporation of hydrated aluminium chloride. The use of this novel cell provides the most accurate representation to‐date of the true evolution conditions inside AGDIBs. Optimisation of the AGDIB cell configuration provided further insight into its electrochemical stability with preliminary investigation of electrolyte and cathode degradation.
The fundamental insights gained from this thesis reveal the complexity of the anode‐electrolyte interface and provide a foundation for future developments to improve the interfacial stability, and therefore commercial viability, of AGDIBs.
This thesis seeks to improve fundamental understanding of the electrochemical interfaces in AGDIBs, focusing particularly on the anode‐electrolyte interface. While there has been significant development of cathode materials for improved energy density, little is known about the impact of corrosion and solid electrolyte interphase (SEI) formation on the aluminium electroplating mechanism in full cell AGDIBs.
Herein, the aluminium anode surface evolution was systematically studied over long cycling by ex situ and quasi‐operando techniques to elucidate the role of plating, corrosion, and SEI growth on cell performance. Electron microscopy revealed a previously unidentified degradation mechanism through inhomogeneous deposition in relation to metal contaminant reduction. X‐ray photoelectron spectroscopy and quasi‐operando soft X‐ray absorption spectroscopy in a custom cell showed the growth of the native aluminium oxide layer into an unstable SEI with the incorporation of hydrated aluminium chloride. The use of this novel cell provides the most accurate representation to‐date of the true evolution conditions inside AGDIBs. Optimisation of the AGDIB cell configuration provided further insight into its electrochemical stability with preliminary investigation of electrolyte and cathode degradation.
The fundamental insights gained from this thesis reveal the complexity of the anode‐electrolyte interface and provide a foundation for future developments to improve the interfacial stability, and therefore commercial viability, of AGDIBs.
Version
Open Access
Date Issued
2025-01-12
Date Awarded
2025-04-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Titirici, Magda
Ryan, Mary
Stephens, Ifan E.L.
Sponsor
Imperial College London
Engineering and Physical Sciences Research Council
Diamond Light Source (Firm)
Grant Number
EP/V038044/1
SI33059
Publisher Department
Department of Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)