A V ₂ CT _x /V ₂ O ₅ /SnO ₂ Ternary Heterostructure <i>-</i> Based Gas Sensor for Highly Selective Detection of Electrolyte Leakage in a Lithium <i>-</i> Ion Battery

This work presents a highly selective gas sensor employing a ternary V₂CT_x/V₂O₅/SnO₂ heterostructure for the early detection of characteristic electrolyte solvent vapors in lithium-ion batteries. To overcome the significant cross-sensitivity between the structurally similar gas molecules, a novel dual-electrode (Au-Au and Au-Ag) sensing configuration featuring both gold and silver contacts was developed on a single sensitive film. This design established distinct Schottky barrier heights, effectively enabling a single material to generate differentiated response patterns for ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC). The enriched multidimensional signal data from this dual-channel output was subsequently processed by a dedicated GRU-Attention (gated recurrent unit-attention mechanism) model, enabling the accurate identification and concentration prediction of each component within gas mixtures. Experimental results demonstrate that the fabricated sensor (Au-V₂CT_x/V₂O₅/SnO₂-Au) exhibits excellent response and recovery performance (17/38 s), high gas response (11.9 to 50 ppm EMC), and a low detection limit (200 ppb). The intelligent sensing system achieves average prediction errors below 7.8% for EMC. Validation in a simulated battery puncture experiment confirms that the gas sensor provides a significantly earlier warning signal compared to traditional voltage monitoring.