Favorable performance of WSe2 monolayer modified by chromium catalyst for sensing thermal runaway gases H2, CO and C2H4 using first-principles theory

Abstract

Detections of thermal runaway gases in the Li-ion batteries (LIBs) is a workable method to evaluate its running status. In this work, first-principles theory is adopted to simulate adsorption and sensing performances of Cr-decorated WSe2 (Cr-WSe2) monolayer upon three typical gases, namely H2, CO and C2H4, in the thermal runaway LIBs. Results indicate that Cr-WSe2 monolayer performs physisorption upon H2 with Ead of −0.37 eV and chemisorption upon CO and C2H4 with Ead of −1.62 and −1.41 eV. The Cr adatom causes strong magnetic behavior to Cr-WSe2 monolayer, which impact the magnetic property of the adsorbed gas molecule as well. The analysis of electronic property suggests the strong potential of Cr-WSe2 monolayer as a high-sensitivity CO and C2H4 sensor, and can be applied as a reusable C2H4 sensor after gas desorption for 70.38 s at 398 K. The analysis of work function (WF) reveal its potential as a potential WF-based gas sensor upon H2 and CO as well. The findings in this work uncover the sensing potential of Cr-WSe2 monolayer upon three typical gases of thermal runaway in the LIBs, which can be explored as a nano gas sensor to perform thermal runaway monitoring using the nano-sensing method.