Ion-conductive polymer membranes for redox flow batteries
File(s)
Author(s)
Wong, Tobias
Type
Thesis
Abstract
Redox flow batteries (RFBs) using aqueous electrolytes promise to play a critical role in the global energy transition. They are candidate technologies for readily deployable, inexpensive and long-lived energy storage of intermittent renewable energy sources. The membrane separating the half-cells in redox flow batteries is a crucial component which can influence lifetime and performance. Its function is to prevent the mixing of the different electrolytes whilst allowing fast transport of the charge-balancing ions. Developing membranes for RFBs has been challenging owing to the conductivity-selectivity trade-off which hinders the simultaneous realisation of high performance and long lifetimes. The work described in this thesis reports the development of membranes which combine concepts across materials chemistry and electrochemical engineering. The structural motifs offered by polymers of intrinsic microporosity (PIMs) are implemented into the highly stable polyether ether ketone (PEEK) polymer backbones and functionalised with ion conductive groups. Physical and electrochemical characterisation of the fabricated membranes are used to reveal the monomer-dependant fast and selective transport of small ions. These sulfonated polymers based on the PEEK backbone enable high efficiency, high power and stable operation of aqueous redox flow batteries based on all-organic and zinc-based architectures.
Version
Open Access
Date Issued
2023-09-28
Date Awarded
2024-03-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Song, Qilei
Sponsor
International Centre for Advanced Materials
Centre for Doctoral Training in the Advanced Characterisation of Materials
Grant Number
CERSE P82018
Publisher Department
Materials & Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)