TMCP: Mario Valvo -"Iron oxides: challenges and possibilities for rechargeable Li- and Na-ion batteries’’
- Date: 06 March, 09:15–10:00
- Location: Ångströmlaboratoriet, Lägerhyddsvägen 1
- Organiser: 4312
- Contact person: Andreas Mattsson
Iron oxides are interesting candidates to possibly replace graphite as negative electrode in Li-ion batteries (LIBs) due to their high theoretical capacity exceeding that of carbonaceous materials. Iron oxides are attractive, as they are easy to synthesize in nanostructured forms via different techniques at low temperatures. They are abundant, cheap, non-toxic and can be efficiently coupled to greener electrode preparations in combination with renewable, water-soluble polymer binders. All these features make iron oxides valuable potential alternatives to graphite, which was flagged by a EU directive in the last years as ‘critical material’ together with Cobalt - another crucial LIB component used as positive electrode.
Differently from graphite, iron oxides do not rely only on insertion of Li+ ions in their structures, but also undergo conversion reactions at low potentials vs. Li+/Li. This leads to amorphization and formation of metallic Fe nanoparticles embedded in a Li2O matrix. This conversion mechanism is reversible to a large extent and accounts for high Li storage capacities in these compounds. Nevertheless, conversion reactions have also intrinsic limitations in terms of energy efficiency and volume variations upon repeated charge/discharge, thus reducing related electrode lifetime.
In this talk, I will discuss about opportunities and limitations of iron oxides in the context of Li- and Na-ion batteries, highlighting briefly their main drawbacks and viable strategies to enable their possible usage in more sustainable rechargeable batteries.