Dirk Henkensmeier

Abstract One promising way to store and distribute large amounts of renewable energy is water electrolysis, coupled with transport of hydrogen in the gas grid and storage in tanks and caverns. The intermittent availability of renewal energy makes it difficult to integrate it with established alkaline water electrolysis technology. Proton exchange membrane (PEM) water electrolysis (PEMEC) is promising, but limited by the necessity to use expensive platinum and iridium catalysts. The expected solu

Traditionally, alkaline water electrolysis (AWE) uses diaphragms to separate anode and cathode and is operated with 5-7 M KOH feed solutions. The ban of asbestos diaphragms led to the development of polymeric diaphragms, which are now the state of the art material. A promising alternative is the ion solvating membrane. Recent developments show that high conductivities can also be obtained in 1 M KOH. A third technology is based on anion exchange membranes (AEM); because these systems use 0-1 M K

Ionically crosslinked PBI/sulfonated polysulfone blend membranes are covalently crosslinked by thermal curing. The crosslinking unit is an aromatic sulfone group.

Multi-gigawatt-scale hydrogen production by water electrolysis is central in the green transition when it comes to storage of energy and forming the basis for sustainable fuels and materials. Alkaline water electrolysis plays a key role in this context, as the scale of implementation is not limited by the availability of scarce and expensive raw materials. Even though it is a mature technology, the new technological context of the renewable energy system demands more from the systems in terms of

Abstract A series of methyl, benzyl, and mixed polybenzimidazolium halides was synthesised and characterised by NMR spectroscopy. Membranes were formed and ion exchanged with hydroxides. These membranes are of interest for use in potentially platinum‐free anionic exchange membrane fuel cells. Crosslinked membranes were obtained by the addition of α,α′‐dibromo‐ p ‐xylene to the casting solution. The ion conductivity of membranes was determined by impedance spectroscopy. A hydroxide conductivity o

Polybenzimidazole (PBI) has been considered as promising membrane material for all-vanadium redox flow batteries (VRFBs) due to its compact morphology that can hinder vanadium crossover. However, its 2–4 mS cm−1 proton conductivity remains a challenge to achieve high energy efficiency. Recently developed PBI membranes showed conductivity up to 18 mS cm−1 by pre-treatment with phosphoric acid (PA) and up to 56 mS cm−1 with KOH. However, since the operation of VRFB uses sulfuric acid (SA), pre-tre