FCH JU Simulation, Statistics and Experiments Coupled to develop Optimized aNd Durable micro-CHP systems using ACcelerated Tests

The main objective of Second Act has been to improve understanding of stack degradation and to propose durability improvements for micro combined heat and power systems using PEMFC and DMFC technology. Through analysis of long term lifetime tests from existing systems provided by industrial partners, identification of major failure modes as well as degradation rates was performed. The major failure modes were then investigated in laboratory scale at single cell and short stack level. Testing were conducted in way to identify degradation at component level in order to be able to implement improvements. For efficient testing, accelerated stress test protocols as well as test protocols for specific failure modes and harsh conditions were validated. Both in-situ and ex-situ characterization techniques were applied in order to investigate localized failure in degradation. A significant modelling effort has been done in the project. Physical as well as empirical modelling has been applied in order to quantify the degradation effects. Statistical analysis of degradation data was also conducted. Analysis of variance was applied in order to investigate lifetime prediction capabilities as well as significance levels in data. Principal component analysis and regression were applied to data subsets in order to correlate events in performance data to operational setpoints as well as to investigate voltage following capabilities.

Simulation, Statistics and Experiments Coupled to develop Optimized aNd Durable ?CHP systems using ACcelerated Tests. Second act aims at improving understanding of stack degradation in order to propose solutions enabling significant lifetime improvements for ?CHP systems using PEMFC or DMFC technology. Project will be thus founded and focused on two efforts: degradation understanding and durability improvement. These efforts will be oriented towards existing systems available in the project thanks to the involvement of three industry partners willing to enhance lifetime and hence competiveness for market deployment. Degradation investigations will be based on lifetime tests information from existing field tests on these systems for relevant description o f failure modes and related performance degradation; from stack and cells specific degradation/durability tests including validated accelerated stress tests emphasizing specific degradation or failure modes in cells and stacks. Understanding will be ensu red by using expertise of research groups in different techniques such as: advanced in-situ local measurements to identify heterogeneities and local performance degradation; ex-situ investigations of components to identify mechanisms; statistical analyses to identify the impact of failure modes and to relate causes to performance losses; and modelling to simulate local performance and degradation in unit cell and stack. Durability improvement will be assessed thanks to the following methodology: exploita tion of all degradation investigations for the proposal of components modifications; selection of most relevant solutions related to most critical degradation issues for their evaluation and demonstration of durability improvements; application of validat ed accelerated tests with improved components in unit cells or stacks tpo demonstrate improvement; and final achievement will be reached with the demonstration of significant measurable improvement at system level.