Fiber Optic Sensors for Detection of Sodium Plating in Sodium-Ion Batteries

Optical fiber sensors integrated into sodium-ion batteries could provide a battery management system (BMS) with information to identify early warning signs of plating, preventing catastrophic failure and maintaining safe operation during fast charging. This work shows the possibility directly detecting plating sodium metal in electrochemical cells by means operando optic evanescent wave (FOEW) spectroscopy. The results include measurements FOEW on bare copper substrates as well hard carbon anodes both half- full-cell configurations. Full using Prussian white cathodes high areal capacities (>1.5 mAh cm–2) are shown cycle pouch cells. also demonstrate sodiation at different rates.