Efficiency and reliability of energy transmission and storage is dependent on the storage capacity of the battery. This is applicable to all systems, ranging from small personal devices to power grids. Batteries are used to supply power to portable devices, to fuel vehicles, and to cause disruptions in the working of electric grids. However, despite the high applicability of batteries, technological advances in the battery industry in meeting the demand for power in the modern world have been slow-paced.
A noteworthy innovation in the battery industry is the pioneering research on liquid-metal rechargeable batteries conducted by Professor Donald Sadoway at the Massachusetts Institute of Technology. The research included application of magnesium-antimony (Mg-Sb) and lead-antimony (Pb-Sb) in the experiments at MIT. In the experiment, electrode and electrolyte layers are heated until they turn into liquid and segregate due to density and immiscibility. Liquid metal batteries have longer lifespans than conventional batteries.
The technology for liquid metal batteries was first proposed in 2009. It was based on the separation of magnesium and antimony by molten salt. The selection of magnesium and antimony at negative and positive electrodes, respectively, was done primarily due to their low cost. Moreover, magnesium exhibited low solubility in molten-salt electrolyte, whereas, antimony was anticipated to discharge higher voltage.
Based on metal composition in battery, the liquid metal battery market trendscan be segmented into Mg-Sb battery, Pb-Sb battery, and Na-S battery. Sodium-sulfur (Na-S) batteries are partially molten-metal batteries. They can be used for storing energy for renewable applications, load leveling, or providing backup source. Raw materials required for producing Na-S batteries are relatively inexpensive; they are also abundantly available. However, the lifespan of Na-S battery is short due to degradation caused by the corrosive nature of its active ingredients viz. sodium and sulfur. Furthermore, usage of Na-S batteries has been limited to large-sized applications.