We have corroborated these finding by testing these membranes in-situ CO2 and water electrolyzers. Our results speak for themselves. The CO2 electrolyzers have run under 3V at 200 mA/cm² with a voltage rise of only between 4 and 6 µV/hr for 3700 hours. Keep in mind, these currents are more than a factor of 4 higher than our closest competitor. For water electrolyzers, our Sustainion™ membranes have helped us embark on the Holy Grail of base metal catalysts using NiFe on stainless steel anodes and NiFeCo cathodes. We can maintain 1 A/cm² at 1.9V at 60oC in 1M KOH for 200 hours with less than 5 mV voltage variation. This is unprecedented since under the same conditions, we have failed to find a single instance in literature of values surpassing the above results by including even high loadings of precious metal catalysts. The cell is still running.
As such, we are expecting to offer these membranes for beta-testing by various academic and industry groups. Based on our current findings, we envision the Sustainion™ membranes making similar breakthroughs in applications of alkaline anion exchange based fuel cells, flow batteries and even electrodiyalsis among other untapped electrochemical applications.
Parts of this work were supported by ARPA-E under contracts DE-AR0000345 and DE-AR0000684 and by 3M. The opinions here are those of the authors and may not reflect the opinions of ARPA-E or 3M. Assistance from colleagues, collaborators and friends from 3M are gratefully acknowledged.