The Preparation And Performance Of The Bipolar Plate Without Agglomerant

Fuel cells get more and more attention of people, because of its high energy density and energy conversion efficiency, and the characteristics of environmental protection. Especially, the proton exchange membrane fuel cell is remarkable than other fuel cells own to its high energy density, low working temperature, quick start, etc. Bipolar plate is one of the most important body part of the fuel cell, and on account of the unsatisfactory performance and cost give rise to the restricting of fuel cell’s development. Therefore, looking for excellent performance, low cost, simple preparation, lightweight bipolar plates has become an important subject in the development of proton exchange membrane fuel cell.This article mainly study on preparation bipolar plates with expanded graphite as the main raw material without resin cornerstone ink, and exploring and improving its performance. First of all, we prepared the raw material of bipolar plate, expanded graphite with the oxide layer method. The structure of expanded graphite were characterized by diffraction analysis(XRD), Fourier transform infrared spectroscopy(FT-IR),thermal gravimetric and scanning electron microscopy. Then we manufacture the bipolar plate of expanded graphite by moulding after ball-milling. And by choosing diverse ball-milling time, moulding pressure and dwell time to explore the influence law of the conductivity and bending strength of bipolar plate in different process conditions. The research indicated that, ball milling time has the greater influence on the properties of the bipolar plate than moulding pressure and the influence of dwell time is relatively small. After that we test some performance of the bipolar plates we made before such as hydrophobic angle, density, thermal stability and corrosion resistance. The measurement indicated that the bipolar plate made by expanded graphite own the performance meet the requirements of DOE completely.After all, in order to make bipolar plates made by expanded graphite possessing more excellent comprehensive performance, we modified by adding additives include flake graphite, artificial graphite, carbon black and carbon fiber. The research indicated that, all kinds of additives pay different role on bipolar plate’s properties. Flake graphite will increase the conductivity with the content increase, but at the same time the bending strength will decline. The increasing of synthetic graphite will deteriorate both conductivity and the bending strength. Conductivity will go up when the content of graphite black adding moderate, but negative consequences result will take place when the content is superfluous. Regardless of quantity, the addition of carbon black on the bending strength is unfavorable. The addition of carbon fiber is useful to bending strength,but it will decrease the conductivity of bipolar plates.