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

使用金属锂阳极有可能将锂电池的比能量和容量提高一个数量级。这将促进可再生能源和电动汽车的突破。目前，技术挑战和安全问题阻碍了金属锂作为电池阳极的大规模使用。这主要是由于其高反应性和有限的循环效率与目前使用的液体有机电解质的组合。固体电解质在与金属锂接触时更稳定，并且会增加电池的安全性。然而，迄今为止，它们的应用受到其低机械稳定性和离子导电性的限制。该研究提案的目标是开发一种用于RLIB的固体电解质，该电解质具有高离子电导率，机械坚固，提供与电极的良好接触，并在与锂金属阳极结合使用时抑制枝晶的生长。主要项目是制作一种高度导电的超离子陶瓷材料的3D支架，该材料与柔性聚合物相互渗透并稳定。陶瓷框架将通过碳支架内的硬模板形成，该碳支架通过Bijel方法或高分辨率3D打印和碳化获得。然后通过原位聚合或通过用熔融聚合物浸渍，用机械稳定聚合物填充所获得的脆性离子传导陶瓷框架。预期这将产生在一个聚合物-陶瓷-复合物中结合陶瓷的离子传导性与聚合物的上级机械稳定性和柔性的固体电解质。在第二个项目中，将探索提高聚电解质的电导率。离子对的一部分的空间分离应形成用于移动离子以与其配位的可用位点，并由此增加离子迁移率。这种新的方法制备这样的材料，使用交联聚电解质将被调查，并可能成为一个有前途的新方法，提高聚电解质的离子电导率。

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.