Electropolymerization of s-Triazines and Their Charge Storage Performance in Aqueous Acidic Electrolytes

Designing novel π-conjugated conductive polymers with abundant redox-active groups is a viable route to achieve high charge storage performance for aqueous energy storage devices. Electropolymerization is a powerful tool to construct conductive polymers. Here, s-triazine is, for the first time, electropolymerized in an aqueous acidic solution on carbon cloth. The polytriazine-coated carbon cloth electrode (PT/CC) exhibits a granular structure, with abundant pores. The charge storage performance is investigated, and a specific capacity of 101.4 mAh g-1 at 1 A g-1 in 1 M H2SO4 is achieved. Additionally, in 1 M ZnSO₄, a specific capacity of 50.3 mAh g-1 at 1 A g-1 can be achieved by the PT/CC. The PT/CC behaves as a battery-type charge storage electrode, and the amino/imino and carbonyl/hydroxyl groups contribute to the charge storage, with cation insertion and extraction. A symmetric aqueous charge storage device assembled with two PT/CC electrodes exhibits an energy density of 12.92 Wh kg-1 and a power density of 250 W kg-1 at 1 A g-1. After 2500 cycles at 10 A g-1, the device retains a specific capacity of 83.3%. This study indicates that the PT is a potential candidate material for an aqueous energy storage device.