Layer-by-layer electrodeposition of poly(o-methoxyaniline)/nickel composites as the electrode material for aqueous charge storage

Developing high-performance and durable electrode materials is critical for advancing electrochemical energy storage technologies. Herein, a layer-by-layer poly( o -methoxyaniline)/Ni nanostructure (LBL-POMA/Ni) composite film is fabricated via a facile alternating-potential electrodeposition strategy on carbon cloth substrates. The composite film is porous, and metallic Ni nanoparticles are uniformly dispersed within the POMA matrix. The LBL-POMA/Ni delivers a high specific capacity of 147.2 mAh g −1 at 1 A g −1 in 1 M H 2 SO 4 , and maintains 90.7% of its initial capacity after 5000 cycles. Compared to POMA and POMA-Ni, the superior charge-storage capability and cycling stability of LBL-POMA/Ni originate from the highly porous structure formed by Ni nanostructure dissolution, which exposes abundant redox active sites for charge storage, and which accelerates the ion diffusion. A symmetric flexible supercapacitor assembled with two LBL-POMA/Ni as electrodes achieves the specific capacity of 54.3 mAh g −1 with an energy density of 17.9 Wh kg −1 and a corresponding power density of 187.5 W kg −1 . It can maintain 95.5% of the initial capacity after 5000 cycles.