First-principles investigation of characteristic gas adsorption on Pt-decorated monolayer AlN for lithium-ion battery thermal runaway detection

Enhancing the safety and reliability of lithium-ion batteries demands the development of novel sensing materials for selective recognition and rapid response to characteristic gases released during thermal runaway events. In this study, we use density functional theory (DFT) calculations to systematically investigate the adsorption behavior and gas-sensing performance of pristine AlN monolayers and platinum-decorated AlN (Pt–AlN) monolayers toward representative decomposition gases—including C 2 H 2 , C 2 H 4 , CO, CH 4 , and HF-which are commonly generated during battery failure. Our results reveal that Pt decoration significantly enhances the gas sensitivity of AlN. While all gas molecules exhibit physisorption on pristine AlN, the Pt-AlN system shows chemisorption characteristics for C 2 H 2 , C 2 H 4 , and CO, whereas physisorption is maintained for CH 4 and HF. Notably, C 2 H 2 demonstrates a high adsorption energy of −3.279 eV, indicating strong interaction and suggesting promising potential for selective capture and removal. Furthermore, the moderate adsorption energies and favorable reversibility of C 2 H 4 and CO on Pt-AlN support the design of low-power, reusable resistive-type gas sensors. This theoretical study expands the application prospects of AlN-based two-dimensional materials in gas sensing and provides new insights into the rational design of highly selective gas sensors. • The Pt decorated AlN monolayers are sensitive to C 2 H 2 , C₂H₄, CO, CH 4 , and HF. • AlN monolayer detects multiple gases with distinct responses. • AlN monolayer shows moderate adsorption and excellent reusability for C₂H₄ and CO sensing.