Fuel cells that operate between approximately 150 ^oC and 250 ^oC accrue certain advantages, most notably facilitated operation with low grade / low cost hydrogen sourced from carbon feedstocks, direct oxidation of high energy density fuels such as dimethyl ether, robust cathode performance in the presence of air contaminants, absence of balance of plant components for stack water management, high quality heat, and readily sourced materials of construction. Fuel cells running at these intermediate temperatures with phosphoric acid as the electrolyte currently hold the record for a commercial lifetime warrantee (1). Yet, lower temperature polymer electrolyte fuel cells (PEFC) operating at under 100 ^oC and comprised of a conductive membrane, electrodes, and gas diffusion layers offer the potential for low cost assembly at high volumes, especially if these components are made with roll-to-roll processes. The better of these two technologies would be a hybrid high temperature Membrane Electrode Assembly (MEA) based on phosphoric acid electrolyte.

Advent Technologies identified and developed a pyridine polymer based TPS^® system using phosphoric acid imbibed into the membrane matrix. Advent’s TPS membranes operate over a wide temperature range from ~120 °C to greater than 200 °C. In 2014, Advent became the licensee of BASF’s PBI MEA (P1100W) and gas diffusion electrode technology. Advent develops, manufactures, and markets both PBI and TPS MEAs. Thus, these two platforms fulfill the promise of the operating features of the phosphoric acid electrolyte with the manufacturing ease of MEAs.

This presentation will present an overview and survey of advances pertaining to medium temperature fuel cells. The survey will include examples of membrane developments including next generation PBI as well as TPS MEAs operating at over 200 °C with direct fuels. We will present several commercial successes utilizing the features of medium temperature fuel cells. Lastly, we will show the results of Advent’s efforts in leveraging our HT MEAs in medium temperature stack technology in the 100W to 3kW range.

1. http://www.doosanfuelcell.com/en/main.do