A DFT study of adsorption of LIBs thermal runaway gases by HfS2 surface decorated with Ag3 and Au3 cluster

In this study, the adsorption properties of Ag₃ and Au₃ clusters decorated HfS₂ surfaces for thermal runaway gases (C₂H₄, CH₄ and CO) of lithium ion batteries (LIBs) were investigated by density functional theory (DFT) method. The Perdew-Burke-Ernzerhof (PBE) functional, the generalized gradient approximation (GGA) and the projection augmented plane wave (PAW) method are used in the calculation, and the van der Waals force is corrected by the DFT-D3 method. It is found that when Ag₃ and Au₃ are located directly above Hf atoms, the binding energy is the largest, and the structure is stable. The pure HfS₂ has the best adsorption performance for C2H4. The adsorption performance of Ag₃@HfS₂ and Au₃@HfS₂ for C₂H₄ and CO is improved, and the adsorption performance for CH₄ is poor. The adsorption of C₂H₄ on Au₃@HfS₂ is stronger than that of Ag₃@HfS₂, and the adsorption of CO on Au₃@HfS₂ is chemical adsorption. CH₄ adsorption has little effect on the electronic structure of the system, and C₂H₄ and CO adsorption have significant electronic interaction. The adsorbed gas reduces the work functions of Ag₃@HfS₂ and Au₃@HfS₂, and C₂H₄ loses the most electrons. The adsorption performance of Ag₃@HfS₂ can be regulated by biaxial strain, and the adsorption energy is the largest when the strain is −8 %. The adsorption of Ag₃@HfS₂ is unstable. Au₃@HfS₂ can be used as a CO and C₂H₄ scavenger at room temperature, and it is expected to be used to monitor the thermal runaway gas of lithium ion batteries at high temperature. This study provides a theoretical basis for thermal runaway gas detection of lithium-ion batteries.