Critical materials for water electrolysers at the example of the energy transition in Germany

Abstract

Summary The present work aims to identify critical materials in water electrolysers with potential future supply constraints. The expected rise in demand for green hydrogen as well as the respective implications on material availability are assessed by conducting a case study for Germany. Furthermore, the recycling of end‐of‐life (EoL) electrolysers is evaluated concerning its potential in ensuring the sustainable supply of the considered materials. As critical materials bear the risk of raising production costs of electrolysers substantially, this article examines the readiness of this technology for industrialisation from a material perspective. Except for titanium, the indicators for each assessed material are scored with a moderate to high (platinum) or mostly high (iridium, scandium and yttrium) supply risk. Hence, the availability of these materials bears the risk of hampering the scale‐up of electrolysis capacity. Although conventional recycling pathways for platinum, iridium and titanium already exist, secondary material from EoL electrolysers will not reduce the dependence on primary resources significantly within the period under consideration—from 2020 until 2050. Notably, the materials identified as critical are used in PEM and high temperature electrolysis, whereas materials in alkaline electrolysis are not exposed to significant supply risks.

Platinum Group Metals: A Review of Resources, Production and Usage with a Focus on Catalysts

“…The increase in Pd demand for auto-catalyst applications has halved the expected lifetime in recent years, but as with the other PGMs, there is no immediate threat. A shift to EVs will influence PGM demand, but electrode catalysts will still generate a significant demand for PGMs, which may represent a supply risk, as outlined by Kiemel et al, for Germany [19].…”

“…Pt, Ir in proton exchange Membranes [19,50] Pt used as cathode catalyst for hydrogen evolution and Ir used as anode catalyst for oxygen evolution as catalyst There is some dissipation on the recycling side. Due to its corrosion resistance and very rare allergic reaction this is a desirable material to use in the body.…”

“…Electrolysers for hydrogen production are another technology that is being deployed worldwide on the tens of MW scale. PEM based electrolysers also use PGM group metals such as Pt and Ir [19,50]. The demand for these metals will grow at a rapid rate with the further uptake of this technology for hydrogen production from renewable electricity sources such as solar PV and wind generators [169].…”

Sustainable Supply of Scandium for the EU Industries from Liquid Iron Chloride Based TiO2 Plants

“…Such products permit the construction of 15-20% lighter aircrafts, which are more fuelefficient, thus reducing the CO 2 footprint [27]. SOFCs operating with renewable energies use water electrolysis as a non-fossil fuel-based process to produce greener electricity [2]. Among the different technologies used for water electrolysis, high temperature electrolysis (HTEL) or solid oxygen electrolysis is a candidate for Sc use.…”

“…The major challenge is a continuous Sc supply chain enabling a massive uptake for producing lightweight, superplastic, high strength, low corrosion and heat resistant AlSc alloys [1]. Scandia stabilised zirconia is increasingly used in solid oxygen fuel cells (SOFC, HTEL) for reaching high fuel performances at relatively lower temperatures [2][3][4]. Further promising uptakes are expected to rise for heat exchangers and 3D printing [1].…”