In 2017, Germany launched a consortium of leading industrial companies to investigate high-volume production of automotive fuel cell stacks. (Earlier post.) Now, the first development phase—Evolution 1—of the stack development is complete; the level achieved will be evaluated by the partners.

The complexity and number of parts of a fuel cell (FC) system is similar to a combustion engine. A key component is the FC stack. This is by contrast, far different to the assembly of a basic engine from a process engineering point of view.

Depending on capacity, the stack alone consists of up to 400 pairings of individual parts (cells) in addition to assembly parts, end plates and system interfaces. On top of this comes the system technology for the operation of the stack in the vehicle.

The ongoing project, which began in 2017 and runs until the end of 2021, is pursuing three main objectives:

1. Automotive high-performance technology: highest power density including lower platinum loading, complete project maturity, achievement of automotive target costs;

2. Exploitation of industrial economies of scale: joint FC specification and system interfaces, scalable FC output, common technological platform; and

3. Mass production capability: selection and evaluation of critical processes, achievement of automotive quality requirements, plant planning for 10,000 and 30,000 stacks per year.

Compared to the battery electric vehicle, in total there are many more components on board, as the ‘charging pole’ is, for all intents and purposes, integrated into the vehicle, because the electrical energy is being generated during the journey as required.

—André Martin, co-cordinator

While benefits can be derived from the results of previous projects AutoStack (2009-2012, EU project, feasibility study) and AutoStack Core (2012-2017, EU project, technological proof of concept), industrialization is the focus of the German project Autostack Industrie.

With sufficient time it will thus be possible to prepare for the production of a large number of vehicles through the development and testing of industrialization-ready high speed processes for stack manufacture and be able to meet future market demands in appropriate phases”, explains Martin. Specifically, this means having a stack product and a manufacturing process that can be converted to industrial scale over a manageable time period of 18 to 24 months following project completion. This fits nicely together with the plans of German automotive manufacturers, who have announced increasing quantities of FC vehicles from 2023 and 2024.

—André Martin

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With respect to resources allocated and the overall budget in the project, Martin estimates that around two-thirds are allotted to product development including the issue of scaling, and a third on production development.

The OEMs in AutoStack Industrie have agreed on a specification and a fundamental system description with the relevant interfaces. After the evaluation of the first development phase, around 60 stacks will be constructed by 2021 in two phases. They will be tested by the participating OEMS, by the ZSW and other project partners.

Depending on the test target objective, different stack sizes will be used. The specified reference output of the stack is 85 kW.

The challenge of long-term durability. Before series maturity, there are certainly a few challenges to overcome. These include long-term durability; the smooth coordination of the main components; and a substantial reduction in the amount of time it takes for the stack to start operation.