Experimental Investigation of Na-Zn Molten Salt Batteries

High-temperature batteries with molten metal electrodes have been explored for more than 50 years. Today, three such devices are commercially available: the sodium-sulphur battery, the ZEBRA (or Na-NiCl2) battery and the Ca-Sb liquid metal battery. In view of the need to integrate large amounts of renewable energy into the electric grid, several alternative stationary energy storage technologies are currently being explored. The main objective of this research is to reduce the storage price and improve the lifetime, sustainability and recyclability of these devices. Within the Horizon 2020 project SOLSTICE1, two different Na-Zn molten salt batteries are currently being developed. While the first cell operates with a solid ceramic electrolyte at 300°C, the second employs a fully liquid electrolyte working at 600°C.
The talk will give an overview of the working principle, challenges and opportunities of the Na-Zn battery concept also highlighting the fluid dynamic aspects of battery operation. Some first experimental results, which have been obtained during the last year, will be presented.