Physical bottom Up Multiscale Modelling for Automotive PEMFC Innovative performance and Durability optimization

Final Report Summary - PUMA MIND (Physical bottom Up Multiscale Modelling for Automotive PEMFC Innovative performance and Durability optimization)

Proton Exchange Membrane Fuel Cells (PEMFCs) are complex nonlinear systems. In order to improve their durability and efficiency and to decrease their cost and required development time, the design of new diagnostic tools is crucial. Powerful mathematical models of the dynamic...

Executive Summary:

Proton Exchange Membrane Fuel Cells (PEMFCs) are complex nonlinear systems. In order to improve their durability and efficiency and to decrease their cost and required development time, the design of new diagnostic tools is crucial.

Powerful mathematical models of the dynamic behavior of PEMFCs are necessary for such design and improvement of diagnostic tools. The project PUMA MIND enhanced the understanding of interactions, competitions and synergies among the mechanisms at multiple working scales from the material to the system level. It lead to the development of robust dynamic macroscopic models for control-command purposes with predictive capabilities.

Most of the novel mathematical models developed by PUMA MIND have been tested experimentally, in order to ensure the applicability on commercial attainable components and catalysts. The most suitable catalysts for the MEA manufacturing technology have been used for these experiments.

The major target outcomes PUMA MIND are a set of simulation tools at the various scales between the material and the system level, which provide a better understanding of the interplay between mechanisms at different scales regarding the catalyst working (reaction mechanisms at the atomic scale), the electrochemistry (including degradation such as catalyst dissolution) and transport mechanisms (including water management), and their relative impact on the whole cell behavior in real automotive application conditions .

Project Context and Objectives:

Description of the project and objectives

The overall objectives and outcomes are:

• A detailed understanding of the multiscale interplaying and their impact on PEMFC performance and durability.

• The validation of the modelling codes with experiments by advanced characterization methods and in-situ diagnostic tools.

• The prediction of improved operating conditions, recovery protocols, material choice and component design.

WP1: Specifications and Technology Watch

The definition of the specifications of the components, the experimental protocols and the operating conditions was completed mainly during the first period of the project. Only the technology watch task continued during the second period. The aim of this task was to follow the advances in the field, which have been relevant for the project. In doing so, the consortium created a document in which all relevant papers which have been published since the start of the project are listed. For each of the papers a short description is provided in this document as well. In addition to this deliverable D1.2, the consortium decided to write a review paper based on the extensive literature research done within WP1 in order to share the gained knowledge with the community and also to increase the visibility of the PUMA MIND project. This comprehensive review paper has currently been published in the Journal of Power Sources.

WP2: Atomistic Modeling Platform

The scientific objectives of WP2 are multifold. From DFT calculations, we aim firstly to describe water and hydrogen peroxide formation on nano-sized platinum particles at the atomic scale (Task 2.1). Secondly, we aim to investigate model processes of the degradation phenomenon of platinum catalysts at the atomic scale (Task 2.2). Finally, we aim to study the influence of the water environment (explicit solvent model) on the adsorption properties of at least the reactant (i.e. molecular oxygen) (Task 2.3). Our ab initio results will allow the estimation of the rate constants of the elementary steps of the ORR mechanism, which are the key ingredients to be injected in the upper working scales of PUMA MIND consortium (especially WP3 and WP4).

WP3: Mesoscale Level Modelling Platform

The main objective of this task is the development and implementation of models able to predict and describe the components and the interfaces structural properties from their chemical composition as well as their associated reactivity and transport properties. For that purpose, in LRCS proposes to develop a mesoscopic kinetic Monte-Carlo Code (KMC) devoted to study the catalyst reactivity and degradation process, based on the elementary kinetic reaction activation barriers obtained by DFT in WP2, in order to explore the ORR intermediates species coverage dynamic in the Inner Layer (IL). The outcomes of this model will be intergraded in a multiscale simulation package called MS LIBER-T (Multiscale Simulator of Lithium Ion Batteries and Electrochemical Reactor Technologies), emerged in 2013, that integrates a new model of electrochemical double layers.

WP4: Full Bottom-Up Multiscale Simulations

The objectives of this during the second period concerned the integration of the data and mechanisms resolved in WP2 and WP3 into the pre-existing CEA full bottom-up multiscale model EDMOND. Intensive multiscale numerical simulations should then be performed in order to calculate the relative impact weight of the different mechanisms on the global cell performance and durability as function of the chemical and structural properties of the materials and components, and of the operation conditions. This will allow to better understand the interplaying of physicochemical and degradation mechanisms at the local scale and to help in the prediction of the performance and durability of the materials at the local level, and to provide guidelines about the processes to be incorporated in the models developed in WP5.

WP5: Macroscopic Single-Cell Models

The objectives of this workpackage during the second reporting period were to achieve the development of the 2D single cell CFD model to incorporate multicomponent performance and degradation functionality and to exploit the multiscale and multiplatform simulation platform to couple macroscopic single cell model and PUMA MIND degradation library. This allows to study the dependence of the global cell performance and durability on the chemical and structural properties of the materials and components and on the operation conditions. Based on these developments, the simulations will provide spatially averaged cell degradation data to WP6 for real-time diagnostics and control.

WP6: Real-Time Diagnostic Models

The goals of this workpackage during the second period was to continue developing and exploit the models and methods presented during the first reporting period. The first objective was to develop a control oriented model described by ordinary differential equations (ODE) based on the mathematical reduced version developed in WP6 for real-time diagnostic purposes. The second objective was to develop and implement on-board monitoring tools to determine fuel cell performance and degradation indicators based on the mathematical model. The final goal is the development of a model based control strategies with the purpose of enhancing the PEMFC performance and durability, and to design dynamic observers for the estimation of states and performance variables in the PEMFC.

WP7: Experimental Validation Platform

The objective of the experimental validation platform during the second period concerned firstly ex situ experiments which will supply specific data to refine the description of the mechanisms in the electrochemical part of the WP4 model. These ex situ analyses will include specific electrochemical experiments such as RRDE and half-cells. Secondly, the SAS fuel cell and single-cell experiments will be performed for respectively WP4 and WP5 models validation for different operating conditions (reactant concentrations, temperature...) according to the protocols specified during the first reporting period. Finally, the electrochemical and structural TEM and XPS characterizations of the aged components will be achieved and data for the validation of the operation strategies based on the online control-command model developed should be provided.

WP8: Coordination of Scientific and Technical Strategy

No major problems of project management occurred in the second reporting period.

The grant agreement was signed by all the partners the 17th of December 2012.

WP9: Dissemination and exploitation

The consortium promoted the R&D results and the project via a number of channels. These included presentations in over 55 scientific events and authoring of 62 publications (journal articles, book chapters and conference proceedings) as reported in D09.02. The project organized two workshops of its own. The first one in June 2014 in Grenoble, France and the second one in March 2015 in Freiburg, Germany. Exploitation consists of ‘leveraging’ and ‘mainstreaming’ of results. The PUMA MIND exploitation plans contain partners’ options and opportunities about how to use the knowledge and tools acquired during the project at organizational, regional, national, European, and/or international levels. As the majority of the intellectual property is deeply embedded in the fuel cell models, patents have not been considered as an attractive option. As per the consortium agreement where several partners have jointly carried out work generating foreground and where their respective share of the work cannot be ascertained, they have joint ownership of such foreground in equal parts. Given the level of maturity of the technology and integration of the different levels, the decision taken is to focus on securing contract research, either from private or public sources (national, European, or international). In this case each of the joint owners shall be entitled to use the foreground as it sees fit, including but not limited to grant non-exclusive licenses to third parties, without any right to sub-license. The consortium believes that results should be of particular interest to automotive companies active in fuel cell vehicles as well as specialist OEMs. Importantly, few PUMA MIND researchers now work for such organizations facilitating technology transfer and supporting the formation of new partnerships.

Project Results:

See final report PDF.

Potential Impact:

See final report PDF.

List of Websites:

https://www.pumamind.eu