Simultaneous Ni and C codeposition by electrolysis was investigated with the aim of obtaining better corrosionresistivity and surface conductivity of a metallic bipolar plate for application in fuel cells and redox flow batteries. The carboncontent in the Ni-C composite plate fell in a range of 9.2~26.2at.% as the amount of carbon in the Ni Watt bath and theroughness of the composite were increased. The Ni-C composite with more than 21.6at.% C content did not show uniformlydispersed carbon. It also displayed micro-sized defects such as cracks and crevices, which result in pitting or crevice corrosion.The corrosion resistance of the Ni-C composite in sulfuric acid is similar with that of pure Ni. Electrochemical test results suchas passivation were not satisfactory; however, the Ni-C composite still displayed less than 10−4A/cm2 passivation currentdensity. Passivation by an anodizing technique could yield better corrosion resistance in the Ni-C composite, approaching thatof pure Ni plating. Surface resistivity of pure Ni after passivation was increased by about 8% compared to pure Ni. On theother hand, the surface resistivity of the Ni-C composite with 13at.% C content was increased by only 1%. It can be confirmedthat the metal plate electrodeposited Ni-C composite can be applied as a bipolar plate for fuel cells and redox flow batteries.