LOW TEMPERATURE PEM FUEL CELL (LT-PEMFC)
The LT-PEMFC is a mature technology used in several industries, like backup power generation, forklift, trains or remote power. But they now also reach consumers, with the fast-growing mobility market.
Materials used for bipolar plates are directly responsible of the fuel cell life time. As of today, the available materials are:
- graphite: very good resistance to corrosion. Thickness and weight make it suitable for stationary applications,
- metal: Very thin and light, but highly prone to corrosion, metallic bipolar plates have a very limited lifetime (~5 000h) and thus are not quite suitable for heavy mobility applications,
- composite: very good resistance to corrosion. Thickness is however still too important (3-4 mm) to provide compact solution for the mobility market.
HYCCO® has developed an innovative composite solution that combines the compactness of metallic solutions (0.3 mm), with the durability of composites materials (20-30 000h) and their lightweights (1.5 g / cm3).
HIGH TEMPERATURE PEM FUEL CELL (HT-PEMFC)
However, LT-PEMFC membranes can be poisoned by impurities (like carbon monoxide) that durably bond with the catalyst and degrades the overall stack performance. For this reason, this technology can only use ultra-pure hydrogen that must reach at least 99.995% of purity. As of today, hydrogen produced by water electrolysis remains the only acceptable source of fuel for those systems.
To mitigate this drawback, systems more tolerant to impurities have emerged. The High Temperature PEMFCs use phosphoric acid doped membranes (PBI for Polybenzimidazole membrane) and work in the range of 160-180°C. HT-PEMFCs have many advantages over the LT-PEMFC systems, as no gas humidification system is needed, which greatly simplify the system. HT-PEMFC are a 1 000 time more tolerant than LT-PEMFC, and thus can run on various fuels, from electrolyser to biogas, through readily available methanol or natural gas.
HYCCO® also developed high temperature bipolar plates suitable for HT-PEMFCs. Our highly conductive plates resist up to 180°C in strong phosphoric acid environment, in order to answer the corrosion issue of traditional material used in HT-PEMFC.
ELECTROLYSEUR AND REDOX FLOW BATTERIES
Both systems also use bipolar plates. HYCCO has produced bipolar plates with polymers specially adapted to the chemistry of REDOX flow batteries or electrolysers. Our preliminary tests have shown excellent results about the lifetime of our materials in strong acidic environment.