Studies on Preparation and Performance of Sodium Silicate/Graphite Conductive Composites

Abstract

Sodium silicate/graphite conductive composites are prepared by mold pressing at room temperature. The effects of graphite content, size of graphite particles, mold pressing pressure, and mold pressing time on the electrical conductivity of composites are discussed. The density and the water content are composites with different graphite content and are also investigated. The optimized preparation conditions are determined. The results show that the electrical conductivity, the density, and the water content of sodium silicate/graphite composite bipolar plate for proton exchange membrane fuel cell (PEMFC) is >100 s/cm, 1.8g/cm3, and 9 wt%, respectively. The density of this composite bipolar plate material is smaller than that of another bipolar plate. This composite bipolar plate material contains gel capillary pores and has sufficient hydrophilicity, which can humidify the proton exchange membrane during the operating process of PEMFC.