Projects

 

Energy storage is undeniably amongst the greatest societal challenges. Batteries will be key enablers but require major progress. Battery materials that promise a step-change in energy density compared with current Li-ion batteries rely on fundamentally different reactions to store charge, e.g. Si alloying or O2 reduction instead of intercalation. They have in common high volume changes on cycling and poor conductivity. For the active component of a battery electrode to function it must be simultaneously in contact with ionic and electronic pathways to electrolyte and current collector. State-of-the-art conducting additives and binders in the composite electrodes cannot ensure ideal contact for such materials and fail to exploit their full potential.
In this project we directly target these fundamental challenges of high-energy batteries by replacing now used conducting additives and binders with flexible organic mixed ion and electron conductors that follow volume changes to ensure at any stage intimate contact with ions and electrons. This requires progress with the fundamental science of such conductors, for which to achieve we develop and combine synthetic, electroanalytic and spectroscopic methods, aided by theory. Mixed conducting polymer gels, designed for the particular storage material, are elaborated for two ultra-high capacity electrodes, the O2 cathode and the Si anode. The significant advantage, next to intimate contact, is that the packing density of active material can be maximized. This boosts energy stored by total electrode mass and volume by rigorously cutting the amount of non-active materials compared with current approaches. The expected overriding scientific impact includes improved understanding of mixed conductors concerning synthesis, structure, conductivity and their behavior in the complex battery environment. This opens up new perspectives for the realm of high-capacity battery materials that demand such a breakthrough to succeed.

 

Dr. Eléonore Mourad, DI Nika Mahne, DI Lukas Schafzahl and Christian Leypold MSc, Yann Petit MSc, are currently working on these topics.

 

The maximum energy density of current lithium-ion batteries is limited by their chemical material composition, and thus such batteries are not satisfactory for the practical application of electric vehicles (EV). Li-air batteries (LAB) have attracted much attention as a possible alternative, offering the highest theoretical energy density (3500 Wh/kg) compared with other current battery systems. But several challenges have to be overcome until a high energy, reliable LAB can be achieved. The aim of the project in cooperation with AIT is to tackle these difficulties through understanding reaction mechanisms and particularly parasitic reactions at the cathode, and developing (electro)chemically stable, highly porous cathode hosts. Already at an early stage of development highly efficient simulation software are used on the basis of experimental data by the company partner AVL List GmbH to support the partners in the areas device safety, cell management and battery design. The partner thinkstep AG contributes with life cycle assessment of LABs in comparison to competing battery systems to allow judging environmental impact and development goals and investigating possible recycling potentials.

 

DI Bettina Schafzahl , DI Aleksej Samojlov and DI Lukas Schafzahl are currently working on these topics.