Ultra-trace Leakage Detection of 1, 2-Dimethoxyethane in Lithium-Ion Battery Electrolyte Via Lacunary Polyoxometalates-Driven Synthesis of NiO/Si-NiWO4/WO3 Heterostructure Nanofibers

Early detection of electrolyte leakage is crucial to prevent thermal runaway in lithium-ion batteries (LIBs). Gas sensors offer a potential solution, however, designing sensing materials that can sensitively identify organic molecules from electrolyte leakage remains a great challenge. Herein, the heterostructured NiO/Si-NiWO4/WO3 nanofibers (NFs) were achieved as a sensing material for highly sensitive detection of 1, 2-dimethoxyethane (DME), a typical electrolyte organic molecule. This was accomplished using the highly negatively charged lacunary polyoxometalates (POMs) TBA4H6[SiW9O34]·2 H2O (α-SiW9) and Ni2+ as precursors, resulting in a series of uniform Si-NiWO4/WO3 decorated NiO NFs synthesized through a two-step process involving electrospinning followed by thermal oxidation. By utilizing the synergistic effect of abundant active interfaces, rapid carrier transfer, and a large specific surface area inherent to NFs, the sensor shows high sensitivity (1.87–300 ppb DME), reliable reproducibility and stability, and superior selectivity. Moreover, the sensor is highly responsive to electrolyte leakage simulations, making it a strong candidate for safety systems of LIBs. The study outlines a cost-effective method for preparing NiO/Si-NiWO4/WO3 NFs, setting a foundation for developing various heterostructured nanomaterials with POMs as precursors.