Ultrasensitive Detection for Lithium-Ion Battery Electrolyte Leakage by Rare-Earth Nd-Doped SnO₂ Nanofibers

The problems of lithium-ion battery (LIB) failure have attracted growing attention since flammable and explosive electrolyte leakage might lead to serious consequences. However, due to the redox-neutral and volatile nature of main electrolyte components, such as dimethyl carbonate (DMC), trace leakages are difficult to detect. Therefore, research on LIB electrolyte sensors is urgent and lacking. Herein, sensors based on rare-earth Nd-doped SnO2 nanofibers are reported for detecting DMC vapor in LIB. The excellent sensitivity (distinct response to 20 ppb DMC), high response (∼38.13–50 ppm DMC), and superior selectivity and stability of 3%Nd-SnO2 suggest that it should be a promising candidate for LIB safety monitors. Meanwhile, it also shows clear and rapid response during the LIB-leakage real-time detection experiment. The doping of Nd endows SnO2 with more oxygen vacancy defects. In addition, the highly active Nd sites greatly enhanced the adsorption energy of DMC on SnO2. All of these features contribute to the improvement of DMC-sensing performances.