Treasure Na-ion anode from trash coke by adept electrolyte selection

• Published in: Journal of power sources Vol. 347; pp. 127 - 135
• Main Authors: Cabello, Marta, Chyrka, Taras, Klee, Rafael, Aragón, María J., Bai, Xue, Lavela, Pedro, Vasylchenko, Gennadiy M., Alcántara, Ricardo, Tirado, José L., Ortiz, Gregorio F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2017
• Subjects: Co-intercalation; Diglyme; Petroleum coke; Shale coke; Sodium-ion batteries; Shale coke; Diglyme; Sodium-ion batteries; Petroleum coke; Co-intercalation
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.02.065

Converting ‘trash’ waste residua to active functional materials ‘treasure’ with high added value is being regarded as a promising way to achieve the sustainable energy demands. Carbonaceous materials cannot insert sodium except when graphite co-intercalates solvents such as diglyme. Here, we show that petroleum coke and shale coke annealed at different temperatures can also insert sodium by reversible intercalation phenomena in a diglyme-based electrolyte. The structural and morphological studies will reveal significant differences justifying their distinct electrochemical behavior. Galvanostatic tests exhibit a flat plateau at about 0.7 V ascribable to the reversible reaction. At the end of the discharge, a Stage-I ternary intercalation compound is detected. Two diglyme molecules are co-intercalated per alkali ion, as evidenced by 1-D Patterson diagrams, FTIR and TGA analyses. The full sodium-ion cell made with P-2500/NaPF6(diglyme)/Na3V2(PO4)3 delivered an initial reversible capacity of 75 mA h g−1 at C rate and an average potential of 2.7 V. Thus, the full cell provides an energy density of 202 W h kg−1. This sodium-ion system can be considered a promising power source that encourages the potential use of low-cost energy storage systems. [Display omitted] •Original way to convert ‘trash’ residua to active material for Na-ion batteries.•Two diglyme molecules are co-intercalated per sodium ion into petroleum coke.•Na-ion cell combining petroleum coke and Na3V2(PO4)3 delivers 202 Whkg−1 at C rate.