Coffee can not only wake us up, but also… charge batteries. Scientists from the Institute of General and Inorganic Chemistry at the Bulgarian Academy of Sciences (BAS) have developed a technology that turns coffee grounds into a material for a new type of sodium-ion battery.
Every day, millions of cups of coffee end up with grounds that go to the trash. However, in the laboratories of the Bulgarian Academy of Sciences, this waste is transformed into a source of energy. “We turn trash into a valuable raw material – "that's what we're doing right now," explains Prof. Radostina Stoyanova, director of the Institute of General and Inorganic Chemistry at the Bulgarian Academy of Sciences, to bTV.
The process begins with heating the sludge to over 1000 degrees, at which point it turns into carbon - the main material for the negative electrode of the battery. "The main problem in the industrial production of sodium-ion batteries is finding a suitable carbon material with the necessary characteristics," says Assoc. Prof. Maria Kalupsazova.
The resulting carbon powder then goes through several steps - drying, processing and heating in a tube furnace under an argon atmosphere. In the final stage, the powder is turned into a paste, which is applied in a thin layer on a metal foil and used to make electrodes.
“In the case of sodium-ion batteries, we have an advantage – we can use cheaper foils and affordable materials“, she adds. The batteries are assembled in an isolated, moisture-free environment, where safety and precision are guaranteed.
The finished batteries can be used to store energy from renewable sources – solar and wind farms. “The topic is extremely important for Bulgaria, as the production of green energy is growing, and the need for storage is also growing“, says Prof. Stoyanova.
In addition to being environmentally friendly, coffee grounds batteries can make Bulgaria more independent of raw material imports. &ndquo;Our country has everything it needs to realize such a battery – "not only China and the US can do it," she emphasizes.
With this development, Bulgarian scientists put the country on the map of global energy innovations. In the race for a more sustainable battery - coffee could be Bulgaria's secret weapon.