<p>Increasing efforts are being made to improve the overall performance of composite bipolar plates for proton exchange membrane fuel cells (PEMFC) through efficient three-dimensional (3D) conductive networks, including metallic fibers and foams. Herein, we proposed a carbon-fenced conductive ultra-long silver nanowires (C@AgNWs) as a novel conductive network former. The addition of only a few percent of C@AgNW with a high aspect ratio to the graphite/phenolic resin composite greatly improved its electrical conductivity, thus reducing the content of the graphite fillers, which could provide a reasonable balance of the electrical conductivity and flexural strength of the composite bipolar plate. The optimal contents of C@AgNWs and graphite was 2.5 and 60%, respectively, and the through-plane electrical conductivity of the bipolar plate was as high as 127.4&#xa0;S/cm, with the flexural strength reaching 51.2&#xa0;MPa. It also showed a low corrosion current density and gas permeability. The maximum power density of PEMFC reached 685 mW·cm^− 2 when using the composite bipolar plates. The graphite/phenolic resin composite bipolar plate could be one of the promising candidates to improve the performance of PEMFC.</p> Graphic Abstract <p></p>