ABSTRACT
The total size of the global rechargeable battery market is estimated to have grown from about 10 billion dollars in 2010 to over 30 billion dollars in 2020, with significant growth of electromobility and energy storage systems. The development of sodium-ion batteries began simultaneously with Li-ion batteries in the early 1970s and 1980s, but the success of Li-ion battery chemistry dominated research in Na-ion batteries, which became almost unnoticeable. The research trend shows development of gel polymer electrolyte and hybrid materials due to additional advantage of significant thermal safety for sodium-ion batteries operating at room temperature. An electrolyte in an oversimplified “old school” approach is responsible for the charge and mass transfer between electrodes. Similar properties are needed for sodium-ion electrolytes and for lithium ones. However, in recent times its role has changed from a “passive” provider of solvent-soluble salt ions.
