Are biologically synthesized electrolytes the future in green energy storage?

The production of renewable energy from solar panels and windmills is rapidly increasing these years. However, one of the biggest hurdles that need to be overcome in the green transition is cost-efficient energy storage to reach the full exploitation of their potential. A promising energy storage technology is redox flow batteries (RFBs), particularly using quinones as electron carriers. The prototypes of quinone batteries have been derived from crude oil, which unfortunately falls short of the ambition of sustainable energy production purely from renewable sources. It is well-known that filamentous fungi have a great capacity for quinone production. and the first RFB with a fungal-produced quinone was recently generated as a proof-of-concept. Here, we give our opinion and perspectives on which challenges need to be solved before an RFB with fungal-produced quinones can be applied in the green transition.