Development of Low Melting Temperature Molten Halogen Salt Electrolytes for Na-Based Liquid Metal Batteries with Low Operating Temperatures below 400°C

Kurzfassung

Molten halogen salts are promising electrolytes for LMBs due to their high stability, superior conductivity and low prices. This work aims to develop molten halogen salts as low temperature and sodium solubility electrolytes for sodium-based LMBs. The molten halogen salt electrolytes are screened and selected by regarding the properties (such as melting temperature, Na solubility related to self-discharge rate, Na+ ionic conductivity) and the material cost. In this work, current research progress on selection of the best molten salt electrolytes for low-cost low-temperature (<450°C) Na-based LMBs will be presented. Based on thermodynamic calculations of the phase diagrams, melting point measurements (via Differential Scanning Calorimetry (DSC) [5] and OptiMelt) and Na solubility measurements, the most promising molten halogen salt electrolytes are selected. Moreover, the test results of these selected molten halogen salt electrolytes in the Na-based LMB test cell will be presented.