Alkaline electrolysers with enhanced durability

ongoing

Today’s alkaline electrolysers are typically operating at voltages exceeding 2 V/cell, corresponding to electrolyser power consumption >54 kWh/kg. Improved performance is often achieved by incorporating platinum-group metals (PGM) in electrode coatings, but the wider adoption of such approach is severely hindered by the limited availability and high cost of PGM. Not only does electrode degradation negatively affect the efficiency of the electrolyser stack, but also the efficiency of the entire system. Degradation also negatively affects CAPEX: due to degradation, the amount of waste heat that needs to be removed from the stack increases, which means that electrolyser components need to be significantly oversized. If electrolyser degradation rate could be reduced, it would result in two-fold benefits: 1) lower operating expenditures via lower energy consumption over electrolyser lifetime, 2) lower capital expenditures via lower level of oversizing of balance-of-plant components needed. Both would positively affect the levelized cost of hydrogen (LCOH). We aim to develop a PGM-free alkaline electrolyser stack with PEM-like performance and low degradation rate. Proposed innovations: • Development of 3D structured, laterally graded, flow-engineered, monolithic porous transport electrodes (PTE), drastically improving electrode kinetics and mass transport compared to state-of-the-art cells • Multi-level computational fluid dynamics (CFD) modelling coupled with advanced X-ray tomography • Novel PGM-free high performance electrocatalysts fabricated using inherently scalable methods • Stack-level improvements and performance validation using 100cm2 and 1000cm2 stack platforms, and benchmarking with state-of-the-art • Building upon the work done by the JRC, the development of harmonised test protocols and accelerated testing procedures for alkaline water electrolysers.