Unraveling the Role of Fluorinated Alkyl Carbonate Additives in Improving Cathode Performance in Sodium-Ion Batteries.

A key issue in the development of sustainable Na-ion batteries (NIBs) is the stability of the electrolyte solution and its ability to form effective passivation layers on both cathode and anode. In this regard, the use of fluorine-based additives is considered a promising direction for improving electrode performance. Fluoroethylene carbonate (FEC) and -difluoroethylene carbonate (DFEC) were demonstrated as additives or cosolvents that form effective passivating surface films in Li-ion batteries.

Improving Amorphous Carbon Anodes for Na Ion Batteries by Surface Treatment of a Presodiated Electrode with AlO.

Disordered carbons are promising anode materials for sodium ion batteries. However, a major drawback of these materials is their low coulombic efficiency in the first cycles, which indicates parasitic reactions. Such reactions can be suppressed by alumina coating on the surface of the anodic materials; more ions are then available for electrochemical activity, and less electrolyte solution is lost.