THE NOVELTIES IN THE DEVELOPMENT OF NA-ION BATTERIES
Today Li-ion batteries dominate as the power sources for portable electronics (mobile phones, lap-top calculators) as well as for electric cars. The main problem with their use is limited sustainability: the raw materials for their production: lithium, cobalt and nickel, are deficient in the earth’s crust. Potential exhaustion of mining resources treats to disable the production of Li-ion batteries in near future. On the other hand, Na-ion batteries, which work on similar principles to Li-ion batteries, present a real sustainable alternative. Namely, the abundance of sodium in the earth’s crust is far higher in comparison to lithium, and Na-ion batteries may be produced from very abundant metals, excluding cobalt and nickel. Thus, the development of Na-ion batteries is the subject of interest of a broad number of research groups worldwide. Currently, the main flaw of Na-ion batteries is lower energy density (~ 50 % that of Li-ion ones), thus the competitiveness in the market is still always relatively low, enabling the first generation of these batteries only complementary use in low-demanding areas, (for example in grid voltage stabilization). However, recently a number of improvements is realized, promising a rapid increase in the competitiveness of Na-ion batteries in all areas of use. In this work, the survey was made on the properties of commercial versions of first-generation batteries. Also, recent advances in improvements of anode and cathode materials which may lead to the second generation of Na-ion batteries are summarized.