Fe₃O₄@uio66 core-shell composite for detection of electrolyte leakage from lithium-ion batteries

Fe₃O₄is an environmentally friendly gas sensing material with high response, but the cross-response to various analytes and poor thermal stability limit its practical applications. In this work, we prepared Fe₃O₄@uio66 core-shell composite via a facile method. The selective response to volatile organic compounds, especially to electrolyte vapors of lithium-ion batteries, as well as long-term stability of Fe₃O₄@uio66 has been dramatically enhanced compared to pure Fe₃O₄, due to the preconcentrator feature and thermal stability of the uio66 thin shell. Real-time detection of electrolyte leakage for an actual punctured lithium-ion battery was further demonstrated. The Fe₃O₄@uio66 sensor, after aging for 3 months, was able to detect the electrolyte leakage in 30 s, while the voltage of the punctured battery was maintained at the same level as that of a pristine battery over 6 h. This practical test results verified ability of the Fe₃O₄@uio66 sensor with long-term aging stability for hours of early safety warning of lithium-ion batteries.