▎ 摘　　要

Conductive polyaniline (PANI) has been used as electrode materials in battery and supercapacitor for decades. However, there are few publications on PANI electrodes for seawater batteries because of its worse machinability and conductivity. This study demonstrates a durable and ultra-stable conductive PANI/MnO2/graphene oxide (PMGO) composite cathode synthesized by an in-situ electrochemical method on the graphite paper with excellent machinability and conductivity. The component, structures, and properties of the materials are characterized by FTIR, XRD, SEM, XPS, and other methods. The result reveals that the synchronization of polymerization and composite can assure PANI, MnO2, and graphene oxide(GO) form a nanocomposite 3D porous network with uniform dispersion. It exhibits better conductivity, higher discharge voltage (1.46 V average working voltage), lower polarization, and excellent discharge performance (500 similar to 600 W.h.kg(-1) specific energy) in the Mg seawater battery compared with the pressed PANI electrode and AgCl electrode. The PMGO composite cathode overcomes the disadvantage of PANI electrode, and is expected to be used in actual production.