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

金属锂阳极的使用有可能使锂电池的比能量和容量增加高达一个数量级。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。这主要是由于它的高反应性和有限的循环效率与目前使用的液体有机电解液相结合。固体电解液与金属锂接触时更稳定，会增加电池的安全性。然而，由于其机械稳定性和离子导电性较低，其应用受到了限制。这项研究计划的目标是开发一种用于RLIB的固体电解质，它具有高的离子导电率，机械性能坚固，与电极接触良好，与锂金属阳极连接时抑制树枝晶的生长。主要项目是用一种高导电性的快离子陶瓷材料与柔性聚合物相互渗透并稳定下来，制造出一种3D支架。陶瓷框架将通过碳支架内的硬模板形成，碳支架是通过Bijel方法或高分辨率3D打印和碳化获得的。然后，通过原位聚合或熔融聚合物浸渍，在所获得的脆性离子导电陶瓷框架中填充机械稳定聚合物。预计这将产生一种固体电解质，将陶瓷的离子导电性与聚合物的卓越机械稳定性和灵活性结合在一个聚合物-陶瓷-复合材料中。在第二个项目中，将探索提高聚电解质的导电性。部分离子对的空间分离应该形成可用于移动离子的位置，从而增加离子的迁移率。这种利用交联型聚电解质制备这种材料的新方法将被研究，并可能成为一种很有前途的提高聚电解质离子电导率的新方法。

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.