HyperSolar Inc. has recently filed for a joint patent with University of California – Santa Barbara for a recent discovery on a polymer coating that acts as both protective and electrically conductive layer, which may find a broad field of applications, especially fuel cells.
Unlike metals and semiconductors, polymers are intrinsically electrically non-conducting. That’s why most of them are used as insulators, for instance, those that encapsulate copper wirings. However, some polymers exhibit electrical conductivity. Polyaniline, for instance may exhibit semiconductor properties depending on its processing pH.
HyperSolar, producers of renewable hydrogen using water and sunlight, was seeking for a polymer coating that would indulge electrical conductivity while protecting their devices from photocorrosion, when they found out that the coating they have discovered can also largely impact fuel cells industry and other products that involve electrocatalysis.
CEO of HyperSolar, Tim Young, said, “A big hurdle in our solar to hydrogen conversion process is the stabilization of the electrodes against photocorrosion. We recently developed an efficient and low cost protective polymer coating that allows for good electrical conductivity as well as preventing photo-corrosion.
This was a significant achievement for solar to hydrogen production. However, our continued research has revealed that this coating may offer broad benefits in many electrocatalysis applications, such as fuel cells.”
If solar cells convert light energy into electricity, fuel cells convert chemical energy into electricity by a reduction-oxidation (redox) chemical reaction. For instance, hydrogen or methanol fuel reacts with oxygen forming water or carbon dioxide, respectively. However, this reaction also involves corrosion to the electrodes used, the reason why platinum is used as electrode for its resistance to corrosion.
When coated with a protective polymer coating that also allows electrical conductivity, cheaper metals can replace expensive platinum electrodes, the most expensive component in fuel cells.