Glyme solvated Na and Li-ion capacitors based on co-intercalation process using pencil graphite as battery type electrode

• Published in: Journal of power sources Vol. 543; p. 231823
• Main Authors: Divya, Madhusoodhanan Lathika, Lee, Yun-Sung, Aravindan, Vanchiappan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.09.2022
• Subjects: Alkali metal ion hybrid supercapacitors; Co-intercalation; Glyme solvated Na and Li-ion capacitors; Kinetic mismatch; Pencil graphite; Solvated ion intercalation; Glyme solvated Na and Li-ion capacitors; Solvated ion intercalation; Alkali metal ion hybrid supercapacitors; Pencil graphite; Kinetic mismatch; Co-intercalation
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2022.231823

Co-intercalation, intercalation of solvated ions received significant research interest in the last decade mainly due to faster charge-discharge kinetics with enhanced diffusion and more excellent stability. Moreover, for the assembly of alkali metal-ion hybrid supercapacitors, with battery type anode and capacitive cathode, a co-intercalation-based anode is a suitable option to avoid the kinetic mismatch between the two electrodes and hence can guarantee better performance. In the present work, we considered pencil graphite (PG B), a cheap and readily available graphite silica composite, as a battery-type anode and commercial activated carbon (AC) as cathode for the assembly of glyme solvated Na and Li-ion capacitors ((PG B/1 M NaCF3SO3 in diglyme/AC) gs−NIC & ((PG B/1 M LiPF6 in tetraglyme/AC) gs−LIC). Such device prototypes could exhibit maximum energy-power storage capability of 78.7 Wh kg−1 and 3.73 kW kg−1 for gs−NIC and 47 Wh kg−1 and 3.13 kW kg−1 for gs−LIC. Besides, the gs−NIC system with the minimum capacity and kinetic imbalance between the two electrodes displayed brilliant cyclic stability of >97% capacity retention after 6000 charge-discharge cycles at a current density of 1 A g−1. However, the co-intercalation electrolyte system (salt and solvent) plays a vital role in the device's overall performance. •High-performance Li-ion and Na-ion capacitors are fabricated with pencil graphite.•“Glyme” family solvents are used to enable solvent-co-intercalation.•Usage of “Glyme” family solvents results in a trade-off between cell safety and energy.•Max. energy density of 47 and 78.7 Wh kg−1 is noted for Li and Na-ion capacitors.