The major drawback of renewable electricity sources like wind or solar is intermittency due to demand and climate conditions. Energy storage is thus a crucial issue for a fully sustainable energy paradigm based on renewable sources of electrical power. (Fig. 1)
Hydrogen produced by water electrolysis during base load moments, stored and converted back to electricity through the inverse reaction, is the ideal energy vector. The possibility of large-scale use of hydrogen as a transport fuel massively increases the potential for renewables and base-load electricity supply. The Unitized Regenerative Fuel Cell (URFC) including in the same device an electrolyzer (EL) that converts electricity in hydrogen and oxygen, and a Fuel Cell (FC) producing electricity on demand by using the stored hydrogen and oxygen, is an enabler technology (Fig. 2).
The cost, weight and volume of an URFC are potentially lower than the combination of separate FC and EL units, but the materials and the device critical function requirements are severe (Fig. 3).
The simplification of the thermal and water management systems, the discovery of electrolytes less sensitive to humidity and platinum-free electrocatalysts are key challenges for the URFC technology.
Project UniRCell - Unitised Regenerative Fuel Cell for Efficient Renewable Energy Supply: from Materials to Device aims to develop a new generation of environmentally sustainable, high-performance and low cost materials by demonstrating their application in a prototype URFC.
The work plan is organized in innovation supporting actions and technical activities focused on the:
-development of novel electrolytes;
-development of novel OER/ORR and HER/HOR bifunctional electrocatalysts based on;
-integration of membrane electrode assemblies through evaluation of different electrode configurations, gas diffusion layers and separator plates;
-analytical and experimental critical function/validation of the components in laboratory FC, EL and URFC prototypes.
Modelling approaches are implemented in various activities in order to gain insight on:
-atomistic features of the relationships between structure, ionic transport and electrocatalysis;
-dynamic effects of two-phase flow, heat and mass transfer on device performance optimization.
Funded by COMPETE 2020 and FCT within the framework of the “Programa de Actividades Conjuntas”, the UniRCell research team combines the expertise in ionic conductors from UAveiro/CICECO and UTAD/CQ-VR to develop electrolytes, the materials chemistry from REQUIMTE/LAQV and the surface science from LSRELCM/FEUP acting together on the preparation and evaluation of electrocatalysts, and the transport phenomena engineering of FEUP/CEFT for device integration, testing and optimization.
UniRCell is thus an opportunity to develop and consolidate R&D activities on hydrogen and fuel cells technologies in Portugal, now scarce and lacking critical mass, by proving several training opportunities and scientific jobs.