Layer-by-Layer Films of Poly( <i>o</i> -methoxyaniline) and Poly( <i>o</i> -aminophenol) Synthesized by Electropolymerization for Electrochemical Energy Storage

Conducting polymers exhibit the possibility of achieving a high electrochemical energy storage performance. Here, layer-by-layer films of poly(o-methoxyaniline) and poly(o-aminophenol) (LBL-POMA/POAP) are constructed by two-step potentiostatic electropolymerization. LBL-POMA/POAP is characterized, and the charge storage performance in 0.1 M HClO4, 1 M ZnSO4, and the choline chloride-ethylene glycol deep eutectic solvent (DES) is evaluated. The highest specific capacity of LBL-POMA/POAP is achieved in 0.1 M HClO4, with the specific capacity reaching 153.6 mAh g–1 at 1 A g–1, and after 2000 cycles, the capacity retention is 87.9%. In 1 M ZnSO4 and in the DES, LBL-POMA/POAP exhibits an inferior charge storage performance than in 0.1 M HClO4. Compared to the POMA and POAP films, the high charge storage performance results from abundant active sites for redox reactions, the highly porous structure, and more facile ion transport. The charge storage mechanism is also investigated, which involves the redox of carbonyl/hydroxyl groups and amino/imino groups. Symmetric supercapacitors are assembled using two LBL-POMA/POAP films with a gel electrolyte, and the charge storage performance of the supercapacitor is also evaluated.