Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
ACS Sens. 2022 Feb 25;7(2):674-683. doi: 10.1021/acssensors.2c00113. Epub 2022 Feb 16.
Detection of toxic and flammable gases and volatile organic compounds (VOCs) released from Li-ion batteries during thermal runaway can generate an early warning. A submicron (∼0.15 μm)-thick poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) sensor film is coated on a platinum electrode through a facile aqueous dispersion. The resulting sensor reliably detected different volatile organic compounds (VOCs) released during the early stages of thermal runaway of lithium-ion batteries (LIBs) even at low concentrations. The single-electrode sensor utilizes impedance spectroscopy to measure ethyl methyl carbonate and methyl formate concentrations at 5, 15, and 30 ppm independently and in various combinations using ethanol as a reference. In contrast to DC resistance measurement, which provides a single parameter, impedance spectroscopy provides a wealth of information, including impedance and phase angle at multiple frequencies as well as fitted charge transfer resistance and constant-phase elements. Different analytes influence the measurement of different parameters to varying degrees, enabling distinction using a single sensing material. The response time for ethyl methyl carbonate was measured to be 6 s. Three principal components (PCs) preserve more than 95% of information and efficiently enable discrimination of different classes of analytes. Application of low-power PEDOT:PSS-based gas sensors will facilitate cost-effective early detection of VOCs and provide early warning to battery management systems (BMS), potentially mitigating catastrophic thermal runaway events.
检测锂离子电池热失控过程中释放的有毒和易燃气体以及挥发性有机化合物（VOCs）可以产生预警。通过简单的水基分散法，在铂电极上涂覆了一层亚微米（约 0.15 μm）厚的聚（3,4-亚乙基二氧噻吩）聚苯乙烯磺酸盐（PEDOT：PSS）传感器薄膜。该传感器能够可靠地检测锂离子电池（LIB）热失控早期释放的不同挥发性有机化合物（VOCs），即使在低浓度下也是如此。该单电极传感器利用阻抗谱法测量乙基甲基碳酸酯和甲酸甲酯在 5、15 和 30 ppm 下的浓度，同时使用乙醇作为参考独立且以各种组合进行测量。与仅提供单个参数的直流电阻测量不同，阻抗谱法提供了丰富的信息，包括多个频率下的阻抗和相位角，以及拟合的电荷转移电阻和恒相元件。不同的分析物以不同的程度影响不同参数的测量，从而可以使用单一的传感材料进行区分。测量乙基甲基碳酸酯的响应时间为 6 s。三个主成分（PC）保留了超过 95%的信息，并有效地实现了不同类别的分析物的区分。基于低功耗 PEDOT：PSS 的气体传感器的应用将有助于经济高效地早期检测 VOCs，并为电池管理系统（BMS）提供预警，从而可能减轻灾难性的热失控事件。
