With 98.3 percent of lithium-ion batteries ending up in landfill, it’s clear that we desperately need to overhaul how we produce and dispose of the batteries that fuel our devices. Startup CellStack is tackling this by improving battery performance. Meanwhile, Tozero is a company focused on improving the battery recycling process. But, what if batteries didn’t need recycling? What if they were made from living cellulose and simply biodegraded once we were done with them?
Enter: the fungal battery. No, not your flatmate’s shelf of the fridge that’s grown so alive with mould it could well be its own energy source. But, a new design from researchers at EMPA’s Cellulose and Wood Materials laboratory. Unlike conventional batteries which take 100 years to only partly decompose, the fungal battery biodegrades in a matter of weeks.
Fungi: “A novel approach”
“This work was inspired by previous projects that focused on developing green electronics,” Carolina Reyes from EMPA told RESET. “The use of fungi to make MFCs [microbial fuel cells] appeared to be a novel approach.”
The design mixes fungal cells into ink and then prints out the battery components using a 3D printer (a method known as direct ink writing). The battery then has fungal electrodes which use nutrients to create power. Mixing fungi into ink without killing them off was a particular challenge for the team. That’s why “the fungi we selected were quite robust and could remain alive even after these steps.”
The Empa team creating the fungal battery While regular batteries leak toxic chemicals into our ecosystems and waterways, the fungal battery is completely non-toxic. The wax, carbon and cellulose that it’s made from don’t harm the environment. And the white-rot fungus actually assists the cellulose in degrading.
What’s the future of the fungal battery?
While the fungal battery isn’t available commercially yet, the design has potential. The research project has proven that fungal batteries can be 3D printed using direct ink writing methods. Fungal batteries could be used to power sensors that record temperature and humidity; “we envision their use in agricultural fields and forests”, Reyes tells us. And from microcomputers to robots to tools for space exploration, several other devices could get their energy source from fungus in the future. It might not be what you want to hear when you’re cleaning out the back of your fridge, but it’s time to let the fungus take over.
