Enabling cost reduction on Alkali Electrolyzers by Innovative Plastic Compounds

Facing the ramp up of the electrolyzer market with quite ambitious targets of >30GW Power in EU by 2030, the costs of the systems need to be reduced for efficient business scenarios. According to a prediction in the IEA – Global Hydrogen Review 2022, AWE (Alkali Water Electrolyzer) will be producing almost 2/3 of green hydrogen by 2030, due to that it is essential having a closer look at the components of an AWE like the frame of the stack which distributes the media, withstands the inner pressure of up to 35 bars and gives the system its shape and rigidity. Today, this frame is made of either multicomponent materials containing quite expensive polymers and/or using a supportive metal ring. This frame accounts for 14-20% of the costs of a AWE stack according to Zao et. al. [1]. MOCOM Compounds investigated the market and developed a polyphenylene sulfide (PPS) compound containing a filler which indicates to be resistant against 30% potassium hydroxide solution for usage in AWE frames and insulator plates. During the development, the temperature resistance of the new composition was tested compared to unfilled PPS, glass-fiber filled PPS, as well as PPSU and PSU. To simplify storage testing, 30% NaOH solution was used instead of 30% KOH solution based on a positive pre-investigation of comparability. A stable behavior at 90°C in 30% NaOH over 672h was observed without degradation of the mechanical performance in modulus, tensile strength, elongation at break and even Charpy unnotched impact performance. This was not the case for PPS with glass-fiber. Starting at a higher mechanical level, a continuous degradation and drop in performance were observed and documented for Tedur L PPS GF30 (standard glass fiber).
The new Tedur L PPS 4030 NC1049-24 compound enables to make an AWE frame out of a 1K solution with comprehensive cost reduction potential of up to 40% in the raw material at elevated creep performance. It also enables the chance for a 2K solution. Tedur L PPS 4030 NC1049-24 can be co-injected and combined with other Tedur L PPS compounds with glass fibers and/or mineral fillers for structural improvement and further cost reduction for each frame. This can mean in total a cost benefit of more than 50% in raw material costs.