Constructing High‐Performance Composite Bipolar Plates via Multidimensional Carbon Networks

ABSTRACT This study presents a facile route to fabricate a high‐performance composite bipolar plate (CBP) by incorporating multidimensional carbon materials into a polyvinylidene fluoride (PVDF) matrix. Zero‐, one‐, and two‐dimensional carbon materials establish a percolating conductive network, thereby optimizing the electrical and mechanical properties of CBP even at low filler loading. Besides, Ketjen black adsorbs on the PVDF nanoparticles during the high‐speed stirring, acting as a physical spacer that prevents PVDF re‐aggregation. The electrical conductivity reaches a peak value of 103.43 S/cm at a carbon content of 55%, with a corresponding flexural strength of 26.17 MPa, exceeding the most reported CBP with high carbon content. The multiple charge–discharge cycling test is carried out in the zinc‐bromine flow battery, and the variation of energy efficiencies, coulombic efficiencies, and voltage efficiencies is less than ±1.5% at the current density of 30–70 mA cm⁻², demonstrating the excellent cycling stability.