Scale-up of PTFE-Based Gas Diffusion Electrodes from Lab Scale to Stack Level Using Polymer-Coated Current Collectors

In this work, we will present a novel current collector concept that allows the scale-up of PTFE-based gas diffusion electrodes (GDEs) from an initial 5 cm 2 to 300 cm 2 geometric area. It is very well known that PTFE-based GDEs are very good solutions to circumvent flooding, however, due to the insulating nature of PTFE, scale-up was so far not addressed. Our novel current collector concept was first demonstrated in the so-called "grid" current collector design and was later transferred into a so-called "monopolar design". We show the importance of an insulating polymer coating on the surfaces of the current collector that are in contact with the bulk electrolyte to suppress hydrogen evolution. Later on, our new concept was transferred and optimized for the operation of 100 cm 2 PTFE-based GDEs. The GDEs plus current collector were finally transferred into a stack comprising 5 electrodes with a total cathode surface area of 1500 cm 2 . Overall, we will demonstrate our new concept from the lab scale to the stack level and will talk about future use-case scenarios of our new technology.