Team Electroactive Nanomaterials
Nanostructuring has a profound effect on the materials properties and is considered one of the key routes towards the improvement of their efficiency. The performance of already known materials can be strongly enhanced by decreasing the crystal size to only a few nanometers and by judiciously designing their nanomorphology. The team “Electroactive Nanomaterials” works at the development of novel synthetic methods for nanostructured materials for electrochemical energy conversion and storage applications, as well as understanding and controlling the processes influencing charge transfer and charge transport properties on the nanoscale.
Main research topics: Electroactive Nanomaterials
Fast charging batteries, more efficient electrocatalysts: these and many other electrochemical applications greatly benefit from nanostructuring, which has a profound effect on the materials properties and is considered one of the key routes towards the improvement of their efficiency. The team “Electroactive Nanomaterials” aims at the development of novel optimized morphologies of materials for energy conversion and storage applications, as well as understanding the processes influencing charge transfer and charge transport properties on the nanoscale.
We explore chemical strategies for the fabrication of ultrasmall metal oxides nanoparticles using aqueous and non-aqueous synthesis routs, as well as defined metal oxide 3D-scaffolds with a high interface area and a continuous charge transport pathways. Our current projects include iridium-based electrocatalysts for polymer electrolyte membrane (PEM) water electrolysis with a minimized Ir content, and electrode morphologies for fast charging Li-ion batteries with an increased energy density.
An increasing need for high energy density and fast charging Li-ion batteries demands the development of novel electrode morphologies. Our team works on SnO2-based conversion/alloying-type anodes and high voltage olivine-structured cathodes LiMPO4 (M = Fe, Mn, Co, Ni) that feature high energy densities but suffer from various drawbacks such as high volume changes or low electronic conductivity. To address these challenges and improve the electrode performance we use a combinations of morphology optimization (such as nanoscaling and the formation of hybrids with carbonaceous conducting materials) and changing bulk properties via doping with different ions.
PEM electrolysis enables sustainable generation of hydrogen with high efficiency, but the large scale application is currently limited by the high cost of its components and in particular iridium used to catalyze the oxygen evolution reaction (OER) process. A drastic decrease in the Ir volumetric packing density in the electrode assembly is required to make PEM technology economically feasible for the large scale hydrogen generation. We develop scalable approaches to prepare dimensionally stable OER catalyst with a very low Ir volumetric loading density but very high OER activity by developing complex porous conductive oxide supports (TiO2- and SnO2-based) and conformally coating them with small IrO2 nanoparticles.