Li dendrites and electrolyte leakage are common causes of Li-ion battery failure. H, generated by Li dendrites, and electrolyte vapors have been regarded as gas markers of the early safety warning of Li-ion batteries. SnO-based gas sensors, widely used for a variety of applications, are promising for the early safety detection of Li-ion batteries, which are necessary and urgently required for the development of Li-ion battery systems. However, the traditional SnO sensor, with a single signal, cannot demonstrate intelligent multi-gas recognition. Here, a single dual-mode (direct and alternating current modes) SnO sensor demonstrates clear discrimination of electrolyte vapors and H, released in different states of Li-ion batteries, together with principal component analysis (PCA) analysis. This work provides insight into the intelligent technology of single gas sensors.