Ion-selective membranes for hydrogen-metal hybrid redox flow batteries
File(s)
Author(s)
Petit, Luke
Type
Thesis
Abstract
Batteries are an important class of storage device in meeting the diverse requirements for gridscale renewable energy storage. Lithium-ion batteries are currently the most heavily utilised class of batteries in electric vehicles, mobiles and grid-scale storage. Redox flow batteries (RFBs) have demonstrated great promise for grid-scale storage due largely to the independent scalability of power and energy. RFBs are limited by factors such as expensive cell components including the commercial Nafion membrane, limited lifetime due to accelerated capacity decay and chemical instabilities. Recently, a class of hybrid flow batteries has been developed utilising a liquid electrolyte at one half-cell and a gaseous reaction from the fuel cell at the other half-cell, termed the regenerative fuel cell (RFC). This thesis reports on the application-driven design and characterisation of membranes for hydrogen-metal RFCs.
Firstly, an established RFC using an Earth-abundant manganese electrolyte and hydrogen anode is investigated, with various factors optimised to allow for membrane characterisation. A thin-film composite membrane is developed, using a Tröger’s base containing 4,4’-diamino-3,3’-dimethylbiphenyl polymer (DMBP-TB) selective layer to mitigate lifetime-limiting factors such as electrolyte migration rate (5.16 x 10−3 g h-1) and manganese permeation rate (2.43 x 10−2 mol m−2 h−1), and a chemically stable, porous crosslinked polybenzimidazole (PBI) support. An investigation into the effect of crosslinking in PBI, specifically on the observed enhanced lifetime in regenerative fuel cells, is performed, identifying the internal membrane moisture gradient as a key cause of failure...
Firstly, an established RFC using an Earth-abundant manganese electrolyte and hydrogen anode is investigated, with various factors optimised to allow for membrane characterisation. A thin-film composite membrane is developed, using a Tröger’s base containing 4,4’-diamino-3,3’-dimethylbiphenyl polymer (DMBP-TB) selective layer to mitigate lifetime-limiting factors such as electrolyte migration rate (5.16 x 10−3 g h-1) and manganese permeation rate (2.43 x 10−2 mol m−2 h−1), and a chemically stable, porous crosslinked polybenzimidazole (PBI) support. An investigation into the effect of crosslinking in PBI, specifically on the observed enhanced lifetime in regenerative fuel cells, is performed, identifying the internal membrane moisture gradient as a key cause of failure...
Version
Open Access
Date Issued
2023-09-14
Date Awarded
2024-02-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Song, Qilei
Sponsor
Engineering and Physical Sciences Research Council
Publisher Department
Department of Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)