MAFIA

This interdisciplinary and fundamental research project involves researchers from the “Institut de chimie des milieux et des matériaux de Poitiers”, from the “Institut de chimie de la matière condensée de Bordeaux”, from the “Institut Pprime” in Poitiers and from the Sunergy company. The next breakthroughs in batteries could come from metal-air systems. By selecting the anode material, both energy density and costs can be tailored to target specific applications. Zn is among the most promising anode elements. However, rechargeable zinc-air batteries (ZAB) suffer from poor energy efficiency (= 60%) and low power output mainly due to the sluggish kinetics of the charge (i.e. oxygen evolution reaction – OER) and discharge (i.e. oxygen reduction reaction - ORR) reactions involved at the positive electrode. There is therefore a critical need to explore and develop new strategies to implement these systems with a truly reversible and stable air electrode (catalysing both OER and ORR). The commonly applied strategy consists in trying to develop ever more active and stable materials. Beyond catalysts development, it has been recently demonstrated that kinetics of OER/ORR can be significantly enhanced using an activation process such as a static magnetic field although the mechanisms involved remain unclear. MAFIA project provides a new approach that could lead to the development of new ZAB systems potentially acting as game-changing application in the field of energy storage and conversion. The main objective of this project (technology readiness level of 4) is thus twofold: (i) design a reversible air electrode and implement it in a prototype ZAB cell operating under static magnetic field, (ii) achieve a highly stable air electrode. For this purpose, it is proposed to: 1) Design innovative carbon allotrope free bifunctional OER/ORR catalysts consisting of Ti or Ta-based MXene supported 3d transition metal-based chalcogenides (M3dX where M3d = Ni, Fe and or Mn and X = O and/or S). Materials will be characterized using a multiscale approach from the macroscopic level down to the nanometer scale. The dynamics of electrode/electrolyte interface will be scrutinized under reaction conditions using an innovative set of in situ techniques (in situ transmission electron microscopy, in situ X-ray diffraction, in situ Raman and infrared spectroscopies). This will allow to shed light on reaction mechanisms, surface reconstruction of catalysts under reaction conditions and ageing phenomena. 2) Rationalize the mechanisms behind the SMF boosting of OER/ORR activity of M3dX/MXene composites, a necessary prerequisite for further development. 3) Design a dedicated ZAB cell operating under static magnetic field. This will allow validating the catalyst design strategy. A complete study of the impact of the static magnetic field on the Zn anode performances will also be performed. This latter study will allow adjusting the electrolyte composition. This PRCE project will enable the academic partners to benefit from Sunergy’s expertise in zinc-based batteries to design a dedicated ZAB working under static magnetic field. This ZAB will be implemented with specifically designed Zn-based negative electrode and electrolyte starting from products already developed by Sunergy. Vice versa, it will enable Sunergy to benefit from the academic partners’ know-how in materials synthesis, characterization as well as in (magneto)electrocatalysis. The PRCE tool is thus useful to accelerate the development of an innovative and efficient ZAB technology.