There is a rapidly increasing interest in new energy battery chemistries, particularly with respect to conducting polymers and especially with a focus on alternative systems to lithium and lithium ion. Herein we present a novel conducting polymer, poly(aniline-co-azure B) (PANAB), synthesized by introducing redox-active azure B into the polyaniline backbone through co-electropolymerization. The resultant PANAB possesses an electrochemical activity over a larger pH range as compared to polyaniline, and can thereby be used as a cathode-active material for a rechargeable aqueous Zn-polymer battery. This battery features large discharge specific capacities of 134.0 and 127.8mAhg−1 at 120 and 1000mAg−1, respectively, while maintaining good cycling performance. The co-electropolymerization strategy provides a route for the synthesis of more conducting polymers with organic redox-active groups for rechargeable batteries, supercapacitors and fuel cells.