The second life of coffee can be even more energizing: Circularity of materials for bio-based electrochemical energy storage devices

Coffee is among the most drunk beverages in the world and its consumption produces massive amounts of waste. Valorization strategies of coffee wastes include production of carbon materials for electrochemical energy storage devices such as batteries, supercapacitors, and fuel cells. Coffee is one of the most consumed beverages in the world. In the linear model adopted so far, its consumption is associated with huge amounts of waste and spent coffee grounds. These wastes, instead, are very interesting secondary raw materials for several circular economy concepts. Nano-structured porous carbon materials obtained by coffee waste are emerging as active materials for electrochemical energy storage devices like supercapacitors and batteries. The major results achieved in the last decade in this high-value exploitation strategy of coffee wastes are summarized to suggest a new sustainable use of coffee waste in the empowerment of the ongoing transition toward a green, electrified, and happier coffee-drinking society. Graphical abstract