Na-ion batteries development
Na-ion batteries are potential alternatives to Li-ion batteries (LIBs). They are based on abundant elements (Na, Fe, Mn, ...) and can be cheaper than their Li-ion counterparts. Although their energy density cannot rival NCM-based Li-ion systems, they can achieve similar performances to LiFePO4 (LFP)- based ones. This makes them interesting alternatives to LIBs for lower cost applications. At present, improvements are needed both on the positive and negative electrode. At the positive side, we look at finding new cathode materials with improved energy density; candidate materials belong to both the layered and polyanionic class of compounds. At the anode, amorphous carbons are used because graphite cannot intercalate Na. Carbons with high capacity and high efficiency are sought, as well as composites with alloying elements.