Preparation of a concentrated carbon black-PTFE dispersion for micro-porous layer of PEMFC

摘要

A micro-porous layer (MPL) of a triple-layer gas diffusion electrode for a PEM fuel cell was made by a dispersion of carbon black and PTFE particles using a non-ionic surfactant such as Triton X-100. Typically, the concentration of the dispersion was below 13 % solids in this paper. We obtained a dispersion of 43% solids by examining the phase separation condition of the carbon black-PTFE dispersion containing Triton X-100. The zeta-potential of the thin dispersion (solids content = 13%) and the thick dispersion(solids content = 43%) are -35mV and -34mV, respectively. The average particle sizes in both dispersions are 500nm. The zeta-potential and the particle size were proven that the dispersibility of dispersion did not change by concentrating dispersion. This concentrated dispersion was suitable for the manufacturing of the MPL sheet of the PEM fuel cell.