Boron‐Catalytic Graphitization Boosting the Production of High‐Performance Carbon Paper at a Moderate Temperature

Carbon papers (CPs), as the substrate materials for gas diffusion layers in proton exchange membrane fuel cells, require high electrical conductivity, efficient gas permeability, and robust mechanical properties, which are unable to be completely satisfied by graphitization at a high temperature. Herein, the boron‐catalytic graphitization of CPs is reported. The boron‐doped CP matrix starts to graphitize at 1800 °C, and evolves into well‐oriented graphitic carbon at 2100 °C. In contrast, the graphitization temperature for undoped CPs increases by several 100 degrees. The boron‐doped CPs achieve the in‐plane electrical conductivity of around 4.8 × 104 S m−1 after graphitization at 2100 °C, which is ≈2 times as high as that of undoped CPs graphitized at 2700 °C. In addition, the tensile strength of the former one is 1.7 times of that of the latter one. The through‐plane gas permeability of boron‐doped CPs is comparable to that of a commercial Toray CP. Boron‐catalytic graphitization at a moderate temperature provides a more sustainable pathway of producing high‐performance CPs.