Characterization of Titanium Diboride Composite Bipolar Plate for Polymer Electrolyte Membrane Fuel Cell

Abstract The effect of varying amounts of graphite and TiB 2 on the electrical conductivity of composite bipolarplates was systematically studied. In this study, Titanium diboride (TiB 2 ) which has a high electrical conductivity,was selected as a filler and a additive material instead of conventional graphite. For proper distribution of the fillerand matrix materials, ball milling using alumina balls was conducted for 1h, and then the hot press method wasapplied for the preparation of composite samples. The results showed a rapid increase in the electrical conduc-tivity of composite bipolar plates at the critical filler content. However, TiB 2 and graphite composite bipolar platesshowed similar increases in the electrical conductivity even though TiB 2 has a higher electrical conductivity thangraphite. In addition, it was also found that a small addition of TiB 2 to graphite filler could be very effective forincreasing the electrical conductivity and flexural strength of the composite bipolar plate.(Received March 14, 2014; Revised March 25, 2014; Accepted April 3, 2014)Key words : Titanium diboride (TiB