Sustainable and cost-effective synthetic route of bio-waste-derived hard carbon anode materials for Sodium-ion batteries

The commercialization of sodium-ion batteries (SIBs) is around the corner for various applications, such as light electromobility and stationary applications. [1-4] The anode of choice in SIBs is hard carbon, a disordered carbon material. One of the greatest advantages of hard carbon is the possibility of using bio-waste precursors, enhancing sustainability and providing cheap material price from its abundance. However, the bio-waste hard carbons synthetic route often undergoes a strong acidic/basic pre-/post-treatment for removing impurities and increasing carbon yield. [5,6] However, such a synthetic process is not scalable, and the initial Coulombic efficiency (ICE) is highly reduced, limiting the 1st cycle capacity in the full cells.
We attempted to develop a sustainable synthetic route to replace the traditional methods and be easily scalable. In this work, the physicochemical and electrochemical properties of bio-waste derived hard carbon anodes manufactured by sustainable synthetic route will be presented. [7] The results reveal that bio-waste-derived derived-hard carbon produced via facile and sustainable water washing outperforms those obtained via other non-sustainable processing methods in terms of ICE, capacity uptake, and capacity retention. Moreover, the applicability of the bio-waste-derived hard carbon is demonstrated in a sodium-ion full-cell. Finally, the cost-ecological effectiveness of sustainable processed hard carbon is confirmed by life cycle assessment (LCA) and cost analysis.