Two Concepts for Solid Electrolytes to Increase Battery Capacity and Safety using Lithium Metal Anodes

• Applicant: Dr. Felix Richter
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 265425036

The use of metallic lithium anodes has the potential to increase the specific energy and capacity of lithium batteries by up to an order of magnitude. This would facilitate the breakthrough of renewable energies and electromobility. Currently, technological challenges and safety issues prevent the use of metallic lithium as battery anodes on the large scale. This is mostly due to its high reactivity and limited cycling efficiency in combination with liquid organic electrolytes used today. Solid electrolytes are much more stable in contact with metallic lithium and would increase battery safety. However, their application is limited so far by their low mechanical stability and ionic conductivity. The goal of this research proposal is to develop a solid electrolyte for RLIB, which has high ionic conductivity, is mechanically robust, provides good contact with the electrodes and inhibits the growth of dendrites when used in connection with a lithium metal anode. The main project is to make a 3D scaffold of a highly conductive superionic ceramic material interpenetrated and stabilized with a flexible polymer. The ceramic framework is to be formed by hard templating within a carbon scaffold, which is obtained by means of the bijel methodology or high-resolution 3D printing and carbonization. The obtained brittle ion conducting ceramic frame will then be filled with a mechanically stabilizing polymer by in-situ polymerization or by impregnation with a molten polymer. This is anticipated to produce a solid electrolyte combining the ionic conductivity of the ceramic with the superior mechanical stability and flexibility of the polymer in one polymer-ceramic-composite. In a second project, increasing the conductivity of polyelectrolytes will be explored. Spatial separation of a part of the ion pairs should form available sites for moving ions to coordinate to, and, thereby, increase ion mobility. This new approach of preparing such a material using cross-linked polyelectrolytes will be investigated and may turn out to be a promising new approach of increasing the ionic conductivity of polyelectrolytes.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Dr. Peter Bruce