A new European project coordinated by DTU Energy aims to bring a promising energy conversion technology closer to market by increasing the robustness of the materials used in solid oxide fuel cell and electrolysis units while decreasing production cost.
Cheap and efficient technologies for the conversion and storage of electricity are essential to enable widespread integration of wind and solar power into the energy system. Solid oxide cells (SOC) – electrochemical cells made of ceramics (solid oxides) – are an attractive technology for this purpose: Used as electrolysis cells they can convert electricity to chemical energy by splitting water to form hydrogen, and as fuel cells they can efficiently convert hydrogen back to electrical energy when needed. But considerable cost reductions and a higher robustness are needed to make this technology commercially viable.
Now, a team led by DTU Energy and bringing ten European companies and universities together will tackle these issues in a new European project funded by the Fuels Cells and Hydrogen 2 Joint Undertaking (FCH 2 JU). The project will focus on the stainless steel interconnects and the cathode contact layers, two components which are used to connect several solid oxide cells together in a stack for increased power output, much like batteries are connected together in series.
The stainless steel interconnect is a thin plate of a special steel capable of withstanding the aggressive atmosphere and high temperature in a stack. The interconnect can account for as much as 30% of the total materials cost of a SOC stack. Reducing the price is therefore crucial for making the technology more affordable. The project will do this through a combination of introducing cheaper materials and making the manufacturing process more efficient and streamlined.
A second objective is to increase the robustness of the SOC stack. Today, the weakest link in many SOC stacks is the interface between the interconnect and the cell. Researchers at DTU Energy have come up with a novel solution – termed ‘reactive bonding’ – for improving this interface. Preliminary tests show that reactive bonding may increase the interface toughness by more than a factor of three. The new project will allow the researchers to thoroughly test and optimize the concept.
To achieve these ambitious targets, DTU Energy have brought together a project team covering the entire value and production chain from supply of raw materials to fabrication and testing. The final solution will be implemented and tested by two of Europe’s leading SOC manufacturers, SOLIDpower and Sunfire.
