Thermal Runaway Gas Composition Database (NMC/LFP/Solid-State)

Thermal runaway in lithium-ion batteries is an exothermic, self-propagating failure cascade triggered by internal short circuits, overcharging, or external heating. As cell temperature exceeds ~130–200 °C, successive decomposition reactions occur—electrolyte oxidation, SEI breakdown, cathode oxygen release (especially in NMC), and anode reaction with electrolyte—generating complex, often toxic and flammable gas mixtures. The database systematically documents these emissions across chemistries: NMC cells typically emit high levels of CO, HF, and hydrocarbons due to Ni-rich cathode oxygen release and LiPF₆ hydrolysis; LFP cells produce significantly less HF and fewer flammable gases owing to their thermally stable olivine structure and absence of lattice oxygen; solid-state batteries (e.g., sulfide- or oxide-based) show markedly reduced gas volume and altered speciation (e.g., diminished HF but potential H₂S from sulfide electrolytes) due to suppressed liquid electrolyte volatility and interfacial reactivity. Data are generated using coupled techniques including micro-gas chromatography (μGC), Fourier-transform infrared spectroscopy (FTIR), mass spectrometry (MS), and online gas sensors, with metadata on test protocols (heating rate, state-of-charge, cell format, pressure), enabling cross-study comparison. This empirical foundation informs computational fluid dynamics (CFD) simulations of battery enclosure venting, toxicity exposure limits (e.g., IDLH thresholds), and selection of gas-detection strategies in ESS installations.