Prospects of open cathode fuel cells in future powertrains

Abstract

Fuel cell technology shows great potential as an eco-friendly alternative to conventional internal combustion engines. Conventional internal combustion engines only manage efficiencies of 20–30%, whereas fuel cells can attain efficiencies of up to 40–60%. In contrast to internal combustion engines (IC engines), which release pollutants into the air and worsen global warming, fuel cells only release water (or vapour) in the exhaust. Despite the fast advancements in fuel cell technology, it still lags IC engines in terms of maturity and encounters challenges such as low life, high costs, unreliability, and a lack of hydrogen refuelling infrastructure. Furthermore, fuel cell vehicles are expensive because of the high price of fuel cell stacks and hydrogen storage systems. Therefore, improving fuel cell performance and reducing costs are of utmost importance to fully utilize its potential and make it practical in future powertrains. A noteworthy advancement in clean energy technologies is open cathode fuel cells that generate power reliably and in an eco-friendly manner. There is no longer a requirement for compressed oxygen or air supply systems in open cathode fuel cells, as they offer an exposed cathode surface that allows direct access to ambient air, in contrast to typical closed cathode designs. Open cathode fuel cells are a promising alternative for several renewable energy applications due to their dependence on natural convection for oxygen delivery, which simplifies the system structure and reduces complexity. Moreover, open cathode fuel cells are more efficient at converting energy and provide more power when operated at higher temperatures. Their exceptional power density and efficiency make them ideal for transportation and distributed power generation, among other uses. However, there are still uncertainties that prevent this technology from being widely used, such as managing humidity, temperature, and durability in exposed locations. This chapter provides an overview of open cathode fuel cell technology, including its background, current uses, and potential future developments. In addition, it outlines a strategy for optimizing and characterizing the performance of open cathode fuel cells using a simplified electrochemical–thermodynamic modelling approach.