High-energy aluminium metal-organic batteries

In the proposed project High-Energy Aluminium metal-ORganic Batteries (HEALORB) we will develop novel high-energy aluminium battery based on aluminium metal anode and organic cathode. Organic cathodes have shown promising electrochemical performance in aluminium batteries due to the fact that organic cathodes can circumvent limitations of difficult insertion and side reactions, typically encountered in inorganic hosts. However, state-of-the-art aluminium-organic batteries still face issues that will be addressed in this project. First, they operate through shuttle of the positive chloroaluminate species instead of uncoordinated aluminium ion. This means that not just the amount the Al metal, but also the amount of aluminium electrolyte, acting as anolyte, is determining the anode capacity, which considerably lowers the practical anode/anolyte capacity from the high capacity of the pure aluminium metal. To improve dissociation of aluminium species we will prepare new generation of Al electrolytes and apply chelating additives to improve dissociation of aluminium species. On the cathode side main issue is poor capacity utilization of polymers, which will be addressed through the nanostructurization of cathodes. Nanostructurization will be guided by the determination of transport parameters inside electrodes through the study of electrochemical mechanism with electrochemical impedance. Another approach will be synthesis of polycylic hexaazatrinaphthalene based compounds with inclusion of new redox active groups within the structure. On the anode side, we will investigate aluminium metal deposition at different current densities and its influence on the deposit morphology. Alternative Al structures will be used to achieve lower overpotential of metal plating/stripping and more even aluminium deposition. Study of the battery mechanism will be at the core of this project and will be performed in three main directions. Investigation of cathode mechanism will allow us to monitor active Al species interacting with cathode and tailor Al electrolytes. Electrochemical impedance study will help us to define relevant transport parameters and guide the electrode preparation procedure. Finally, X-ray Raman spectroscopy will allow us to investigate electrochemical reaction in the bulk and verify our surface sensitive techniques (XPS, ATR-IR). Through development of novel high-energy aluminium battery, we will deliver a new battery system that will speed up market penetration of renewable energy sources through cost-effective stationary energy storage.