Electrochemical synthesis and energy storage study of aniline-pyrrole conductive copolymer electrode

Two types of aniline-pyrrole copolymers were designed and synthesized by electrochemical intercalation on the surface of graphite oxide paper and characterized by IR, SEM, and XRD. They were the first to be formed into a seawater battery and an aqueous zinc ion rechargeable battery with magnesium alloy and zinc, respectively. The energy storage and electrochemical performances of the copolymer electrodes were also studied. The results confirm that aniline and pyrrole can be electrochemically synthesized as copolymers (PANPY), and the polymers both have a certain degree of crystallinity and favorable conductivity. The copolymer was nano-spherical when pyrrole content in the monomer is high, while it has nanowire morphology with low pyrrole content. Copolymer prepared with a monomer ratio 1:1 (aniline: pyrrole) is more suitable as a primary battery cathode in a magnesium alloy-seawater battery, which has a specific capacity of 334 mAh & BULL;g � 1 at a constant current discharge of 3.75 mA & BULL;cm 2 to 0.9 V. Nevertheless, the copolymer with a monomer ratio of 2:1 (aniline:pyrrole) is more suitable as a secondary battery cathode, in an aqueous zinc ion battery, and the discharge specific capacity can reach 276 mAh & BULL;g � 1 at 3.75 mA & BULL;cm � 2 constant current discharge to 0.7 V, and 7.5 mA & BULL;cm � 2 charge to 1.85 V. After two hundred cycles, its capacity retention rate maintains >88 %, which is more stable than polyaniline at the same charge-discharge condition. These studies present that designed aniline-pyrrole copolymers have high energy storage and electrochemical stability and can be used as cathode materials for primary and secondary batteries, respectively.

Automated summary

Two types of aniline-pyrrole copolymers were synthesized and used in a seawater battery and an aqueous zinc ion rechargeable battery. The copolymers showed certain crystallinity and conductivity. The copolymer with a 1:1 aniline to pyrrole ratio performed well as a primary battery cathode in the magnesium alloy-seawater battery, while the copolymer with a 2:1 ratio was suitable as a secondary battery cathode in the aqueous zinc ion battery. These copolymers demonstrated high energy storage and electrochemical stability.