Circumneutral concentrated ammonium acetate water in salt electrolyte and argan shell derived carbon for green supercapacitor

Supercapacitors (SC) are playing a central role in the transition to a green economy based on renewable energy sources and electric vehicles. The exponentially growing market of supercapacitor requires to replace flammable, volatile and toxic chemicals such as acetonitrile by cheap and environmentally friendly components. Therefore, valuable strategies are the use of aqueous electrolytes and bioderived components such as biochar-based carbon that enable the valorization of wastes in a circular economy approach. Here we report about a physicochemical study and electrochemical characterization of a supercapacitor based on Argan fruit shell derived carbon electrode and a non-toxic super-concentrated aqueous electrolyte, i.e. a Water In Salt (WIS) solution of ammonium acetate. Indeed, the utilization of WIS enables high voltage which are the main limitation of aqueous based electrolyte. The reported SC featured up to 47 F/g of specific capacitance and 4 Wh/Kg of specific energy at a temperature room temperature To prove the practical applicability of this kind of electrolyte, electrochemical measure at into a wide range of temperatures (from -10 °C to 80°C), have been performed. This preliminary work aims at paving the way towards the design of novel green SCs based on non-dangerous aqueous based electrolyte and sustainable carbon sources.