Enhanced Gas-Sensing Properties of Platinum-Doped InSe Monolayers for Lithium-Ion Battery Emission Monitoring: A Comprehensive DFT Analysis

Thermal runaway in lithium-ion batteries generates toxic and flammable gases such as CO, C₂H₂, and C₂H₄, presenting severe safety risks. Early detection of these gases is essential for battery safety monitoring. In this study, the gas sensing performances of pristine and Pt-doped indium selenide (InSe) monolayers toward CO, C₂H₂, and C₂H₄ were investigated using first-principles density functional theory (DFT). The adsorption energies, charge transfer, and electronic structure changes were systematically analyzed to evaluate sensing sensitivity. Results indicate that pristine InSe exhibits weak interaction with all target gases. However, Pt doping significantly enhances gas adsorption with increased adsorption energies and substantial charge transfer. The Pt dopant also modulates the electronic structure of InSe, which is favorable for sensing signal transduction. These findings demonstrate that Pt-doped InSe monolayers possess excellent selectivity and sensitivity toward critical warning gases from thermal runaway, offering theoretical guidance for the design of high-performance 2D material-based gas sensors.