Plasma-Assisted Surface Modification on the Electrode Interface for Flexible Fiber-Shaped Zn–Polyaniline Batteries

A novel flexible fiber-shaped zinc–polyaniline battery (FZPB) is proposed to enhance the electrochemical performance, mass loading, and stability of polyaniline cathodes. To this end, electron-cyclotron-resonance oxygen plasma-modified carbon fibers are employed. During plasma treatment, on the carbon-fiber surface, O2+ plasma breaks the C–C, C–H, and C–N bonds to form C radicals, while the O2 molecules are broken down to reactive oxygen species (O+, O2+, O2+, and O22+). The C radicals and the reactive oxygen species are combined to homogeneously form oxygen functional groups, such as –OH, –COOH, and –C=O. The surface area and total pore volume of the treated carbon fibers increase as the plasma attacks. During electrodeposition, aniline interacts with the oxygen functional groups to form N–O, N–H bonds, and π–π stacking, resulting in a homogeneous and high-loading polyaniline structure, and improved adhesion between polyaniline and carbon fibers. In FZPB, the cathode with plasma-treated carbon fibers and...