The project should focus on the improved industrialization-ready designs of high efficiency and low cost Balance-of-Plant (BoP) PEMFC system components on the cathode side (compressor, humidification, intercooler, valves, and turbine/expander). The FC stack is also within the scope to be funded, although it is not the focus of the innovation. The FC stack is required to demonstrate the system level performance and may therefore be adapted from existing technology.
Development of a new generation of systems using cost engineering to identify cost reduction potentials for each component and perform design-to-cost activities and trade-offs with other BoP components. As an example: low O2 permeation valves can be used to reduce O2 ingress into the stack and thus decreasing start-up (SU) degradation. The project must include durability testing of the components (or testing at the system level if meaningful) under automotive conditions.
The project must address the following key issues:
- Novel system prototypes that eliminate or reduce issues currently experienced with PEMFC systems such as voltage cycling, SU/SD corrosion which leads to increased degradation
- Freeze start design and system component layout to minimize water pooling and consequent ice blockages and reduction of thermal mass to enable faster start up at sub-zero temperatures
- Air compressor prototypes that simultaneously
- provide higher efficiency at max load point to enable reduction of parasitic power while providing increased durability
- meet automotive dynamic requirements (0-90% power in 0,5s)
- improve flow vs. pressure operating window at low current densities
Optionally the project can also address the following issues:
- Turbine/expanders prototypes that reduce parasitic losses with high recovery efficiency.
- New humidification prototypes that simultaneously
- improve water transfer rates between wet and dry side
- improve durability to meet automotive requirements of 6,000h
- minimize packaging space
- reduce pressure drop
- Intercoolers (gas-to-gas or gas-to-liquid) that simultaneously
- high thermal transfer efficiency
- minimize package space
- reduce pressure drop
To insure the usefulness of the results for the automotive industry, the following methodologies are required:
- Automotive development methods, design to cost, reliability and robustness methods
- Detailed component level simulation for analysis and optimization (e.g. of multiphase transport and phase transition processes including multi-component diffusion and mixing phenomena of humidifiers etc.)
- Sub-system and system level simulation for component specification and assessment of overall performance of different component configurations
- Automated-/hardware-in-the-loop-/accelerated testing methods
Typical PEMFC systems still have important challenges before mass production in transportation may be realised, namely cost, reliability and durability. Some of these challenges can be tackled improving the system components as well as by introducing novel system configurations.
While the technical feasibility has been demonstrated in several configurations, a major challenge remains on the high cost of these solutions due to low production volumes, the use of expensive materials and designs not suitable for automated manufacturing. Moreover, the supply chain for some components is still not in place.
Some of the specific outstanding issues concern the freeze start that is still too long and not reliable for low cost stacks and the water management at low temperatures and subsequent freeze preparation. Some failure modes for key components such as compressor air bearings have still to be solved. Packaging in combination with cost effective solutions remain an issue in view of future integration in mass production of the automotive industry.
In addition, the fuel cell system, power degradation is still too high, caused by events such as start-up/shut-down, fuel starvation and potential cycling. With novel system architecture and component designs, the FC degradation can be reduced to levels equivalent to incumbent technologies.
The biggest cost-down leverage in a FC system is on the cathode side: the components are usually the most expensive and the ones with the highest parasitic power and strongest impact to FC performance.
Additionally, the automotive supply chain needs to be established for some of the components and should be further supported by bringing together OEM and potential n-Tier suppliers in development projects such as the present one.
By addressing design to manufacturing and cost engineering tools, further cost-down potential should be reached on the main BoP components, thus bringing costs in line with positive business cases at the system level, not only for OEMs but also for the entire supply chain.
The project must show that the proposed BoP solutions support the targets at the FC system level. Details on the trade-offs between stack and BoPs including cost estimation are expected. All projects must also produce validated evidence of lifetimes; cost targets and efficiencies throughout life.
The following KPIs are expected to be reached at the FC system level:
- FC system production cost: 100 €/kW at 50 000 units/year production rate
- Maximum power degradation of 10% after 6000 h for passenger cars
Cold Start: Improved freeze start up performance and reliability closer to standard automotive conditions