Fuel Cell technology is seen as one of the key enabling technologies for future zero emission transport and renewable-based energy infrastructure of Europe. Ideally, excess electricity from hydro power, wind power and solar power plants is converted via electrolysers into...
Fuel Cell technology is seen as one of the key enabling technologies for future zero emission transport and renewable-based energy infrastructure of Europe. Ideally, excess electricity from hydro power, wind power and solar power plants is converted via electrolysers into hydrogen to be used as fuel in FC vehicles or stored for later use in times of energy shortage. PEM Fuel Cell systems use (stored) hydrogen (H2) and convert it in electrical energy and heat. Even though the development of PEMFC components and stacks for transport applications have reached a mature level, in which the operational performance specifications are met, certain aspects like manufacturability, production efficiency and production cost have a large improvement potential since they have not been the focus up to this point. Fit-4-AMandA focuses on several critical production steps in the PEMFC technology chain that are still inefficient with respect to cycle time, cost, yield and reliability. Fit-4-AMandA provides a solution to automatize the production process for stacks in order to overcome the inefficiencies.
WP1: The definite setting of the technical requirements focuses on the review of the technical specifications of PEM Fuel Cell and currently available business studies was performed by the Fraunhofer IWU (FhG).
WP2: The re-design of the current stack design and stack components for mass production and design-to-cost with increasing manufacturability of stack with optimized stack component design and identifying innovative production technologies to advance stack-component production beyond state-of-the-art was performed by PM.
WP3: The manufacturing of robotic systems for stack components from EWII has as main goal the development of stack components suitable for automatic production of them. For the production of bipolar plates as one of the stack key components, a baseline report was submitted.
WP4: For the development, manufacturing and testing of technology and machine system for the automatic assembly of fuel cell stacks, USK developed a manufacturing technology for the automated production of fuel cell stack.
WP5: The work of TUC focusses on the development of fast in-line tests methods for automated production of MEAs and stacks.
WP6: The Integration concept for stack components and stacks for UPS’ transport application are main activities of this WP.
WP7: Effective communication of the project results and to pave the way to exploitation of the project results.
-The formulation of the specifications of requirements for the automatic machine that will be producing stacks, which is the centrepiece of the fuel cell systems.
-A technology and business study in the field of fuel cell technologies in the transport sector (parcel delivery), depending on government requirements (latest pollution laws, etc.) and focusing on the production aspects of fuel cells.
-Key production parameters of the EWII BPP manufacturing line has been recorded and compiled.
-Collection of all the specifications related to the FC stack product, the machine design, the machine parameters and processing steps, as well as the quality control measures.
-The fuel cell stack design was adapted - parallel with development of assembly technology and equipment system - according the process requirements of automated manufacturing, assembly, transportation, handling, image processing and testing.
-Provide a list of methods suitable for the fast in-line tests of fuel-cell components and subassemblies.
-Carry out feasibility study, to determine the applicability of the fuel cell technology for a commercial FC electrical vehicles
1 PEM Fuel Cell Stack
PM and EWII in cooperation with USK inspected closely the existing components and identified the features already compatible with mass manufacture as well as the problematic areas that had to be altered. For example, the footprint of the bipolar plates was changed to make them easier to handle by the grippers and alignment features were added to aid the vision system and manipulators to meet very stringent tolerances while operating at high speed. The GDL concept was revised for better automated handling. Stack end plates and tightening system also had to be modified to conform to the hydraulic press. The resulting fuel-cell stacks should have more consistent characteristics, be more reliable due to the automated assembly.
2 Major stack components: MEAs
The targeted work on optimizing the BPP molding was focused on automation, which resulted in the implementation of a supporting tool to make molding tool exchange between production orders more easy. In a process to reduce the raw material loss (scrap) within production, it has been recognized that the scrap rate is related to the overall design of the BPP manufactured. Most specifically, a BPP with outer extremities requires excessive dosage of raw material to fill the extremities, whereas a compact BPP design produces less scrap. A simple progressive approach to scrap reduction therefore involves counseling for the customers in the BPP design phase. Optimization of the material feed machine has at present not lead to increased automation. Improved pass yield has also been studied, and a general gain of experience within the production staff has presently improved the pass yield to an amount, where the rate of discarded plates has been cut in half.
3 Manufacturing processes for stacks
Three methods of stack assembly can be considered: manual, semi-automated, and automated. Depending on the production rate, a suitable assembly process is chosen. At the lowest production rate, a manual assembly is preferable. It consists of workers using their hand to pick and place each element of the fuel-cell stack. The stack is built sequentially at a single workstation. After the pressing and tensioning with tie rods or with compression bands, the finished stack is removed from the workstation and then subjected to testing and conditioning. Because the workers can inspect parts (e.g. BPPs) during the stacking, less quality-control instrumentation (e.g. optical detection system) is needed. At higher production rates, the semi-automatic or automatic stack assembly (see Figure 1) is superior. In semi-automatic stack assembly, repetitive processes such as alternating the BPP and MEAs are automated, but the assembly of the end components (end plates, current collectors, initial cells), pressing and tensioning is done manually.
4 Develop a suite of sufficiently fast and conclusive methods to be implemented as in-line as well as end-of-the-line tests, while minimise the time necessary to perform and evaluate the tests;
More info: http://www.fit-4-amanda.eu.