The institute section Theory and Computation of Energy Materials (IEK-13, https://www.fzjuelich.de/en/iek/iek-13) is the coordinator of the DECODE project. IEK-13 aims at expediting the transition of the energy system by combining theoretical physics, computer simulations and physical modeling to study how energy materials form, function, fade and fail. To advance this agenda, scientists at IEK-13 employ theory and computation to close gaps in understanding structural and mechanistic phenomena in materials, discover or develop physical relations between structure and properties of complex multifunctional components, decipher multiparametric and scale-crossing correlations between materials properties and metrics of performance or lifetime, and enable the model-based diagnosis and optimization of electrochemical devices. Furthermore, IEK-13 research orchestrates modeling and data analytics with artificial intelligence to accelerate the materials workflow from discovery to integration and advance modern lab concepts. In addition to its role as project coordinator, IEK-13@FZJ contributes to: WP1 for theory and computation of electrocatalyic interfaces (to understand the local reaction environment), porous electrodes (to rationalize the distribution of reaction rates) and multi-component devices (to rationalize and predict performance); WP2: by developing integrated modeling workflow; develop and implement approach for integration and joint assessment of modeling and characterization tools; model parameterization (jointly with experimentalists) and model-based analysis of data for use case; and leading WP3 (building DECODE Foundry, and DECODE CPU-like orchestration modules. The institute for Electrochemical process engineering [https://www.fz-juelich.de/en/iek/iek-14] (IEK-14) brings more than 20 years of experience in electrochemical energy conversion, developing solutions for mobile, portable, and stationary applications. IEK-14 conducts research into using liquid energy carriers as fuels and works on groundbreaking innovations for electrochemical conversion systems for the direct generation of hydrogen, syngas, and power by means of electrolysis, co-electrolysis, and fuel cells. In this project, IEK-14 will provide experimental data for the use case PEM water electrolysis in order to verify transferability. The Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN-IEK-11) [https://www.hi-ern.de/en/research/electrocatalytic-interface-engineering-1] investigates and develops material- and process-based solutions for a climate-neutral, sustainable, and cost-effective utilization of renewable energies. The Electrocatalytic Interface Engineering research department directly contributes to DECODE project. The research interests of the department span the whole electrochemical cell: From catalyst development and membrane development over manufacturing of electrodes and membrane electrode assemblies to upscaling and automatization of manufacturing processes. IEK-11 contributes to DECODE project by performing various testing and characterization activities in supporting use cases performed in WP4.