Direct Ethanol Fuel Cells: Ethanol for our future fuel cells?

Ethanol is the most used bio-fuel world-wide with an existing supply chain and infrastructure in many parts around the world. The most attractive direct ethanol fuel cell (DEFC) technology for vehicle applications is based on alkaline membranes, AAEM, enabling the usage of Pt-free catalysts. Also the high efficiency makes DEFC attractive, but the absence of cells and prototypes tested and evaluated in terms of vehicle demands makes the technology more challenging.

The aim of this study is to identify the potential of the DEFCs and to compile the state of the art for the technology from a vehicle perspective. There are several issues need to be addressed before the technology could be scaled up for vehicle applications; issues mainly related to materials, cells, and system solutions of the DEFC itself, but also related to the fuel and comparative studies of competing technologies. Based on this pre-study the following recommendations for future research and development activities have been identifies:

Primary:

Materials and cells

- AAEM-based concepts and development of metal-oxide catalysts.

- investigations how temperature and other operational parameters affects the power density and vehicle installation complexities.

Vehicle

- development of vehicle simulation models to evaluate system design constraints and corresponding vehicle performance.

Secondary:

Fuel

- sensitivity analysis of how the denaturalisation additives affect the overall performance and durability

- extended well-to-wheel analysis to determine the environmental impact.

Techno-economic studies

- potential of DEFC in vehicle applications: comparisons of EVs utilising different technologies: DEFC, DMFC, and PEMFC, in relationship to battery electric vehicles of same size and performance requirements.