Highly Stable Cyclic Performance of Benzoquinone-Based Organic Cathode in Aqueous Zinc Ion Batteries

An organic polymer, poly-(2,3-dithio-1,4-Benzoquinone) (PDBQ) was synthesized through condensation polymerization and characterized by SEM, EDS, XRD, FT-IR, BET, TGA, NMR and XPS. FT-IR results displayed the carbonyl and thio functionality of the material, elemental composition, and chemical states were confirmed by XPS and EDS. The material exhibited a sheet-like interconnected morphology and good thermal stability. The fabricated cathode delivered a high specific capacity of 157.39 mAh g⁻¹ at a current density of 100 mAg⁻¹ with high reversibility in full-cell aqueous zinc ion batteries (AZIBs). The congenital soft structure enhances the reversibility, Zn⁺² insertion-desertion, and stability of the electrode material in coin-cell batteries. Owing to these characteristics the battery delivered higher stability with capacity retention of 97.65 % after 1500 cycles and remained at 73.2 % after 20,000 cycles at a high current density of 2.0 Ag⁻¹ with almost 100 % columbic efficiency. The energy storage behavior of the fabricated cathode was further studied by cyclic voltammetry and electrochemical impedance spectroscopy, as well as the charge storage mechanism through ex-situ FT-IR, EDS, and XPS. These results are promising to achieve the objective of stable organic material as a cathode for AZIBs.