Abstract:Fuel cells, a kind of efficient and environmentally friendly power generation system which can continuously convert chemical energy into electricity directly, are the fourth power generation devices since hydropower, thermal power and nuclear power. Among them, proton exchange membrane fuel cells show prominent advantages of long life, high specific power and specific energy, fast start-up at room temperature, etc. They have displayed promising application potential in both portable power and immobile power with military, transportation and telecommunication uses, and are considered as one of the ideal power sources with high adaptability to future energy and environment situation. The bipolar plate, which is one of the core components of a proton exchange membrane fuel cell, occupies a large part of the quality and cost of the whole battery pack and has the functions of uniformly distributing the reactant gas, conducting current, and concatenating monocells, etc. In order to realize these functions, a qualified bipolar plate should have the characteristics of high thermal conductivity, high electrical conductivity, corrosion resistance, low density, favorable mechanical properties, low cost, easy processing and so on. However, the contemporary bipolar plate products suffer poor matching between corrosion resistance and poor conductivity, also high production cost and short service life. Accordingly, it is crucial for commercial applications of fuel cells to achieve a reasonable matching of the conductivity and corrosion resistance of the bipolar plate materials, in other words, to ensure high corrosion and service life of the entire system resistance in the case of reasonable conductivity. Currently, the commonly used substrate materials of proton exchange membrane fuel cell bipolar plates include graphite mate-rials, metal materials and composites, all of which have different advantages and disadvantages but are nonetheless unsatisfactory. This in recent years has urged intensive and fruitful research efforts to improve bipolar plates’ performance by means of material doping or surface modification, and a majority of modified materials have shown acceptable performance according to the criteria of the United States Department of Energy. This paper systematically summarizes the above three types of bipolar plate materials, with an emphasis on the performances of the combinations of a diverse variety coating materials and substrates (including stainless steel, aluminum alloy, titanium alloy substrates). Finally, the development trend of bipolar plate materials, especially metallic bipolar plates are further discussed.

https://doi.org/10.11896/j.issn.1005-023X.2018.15.008