Structural, electronic, and thermal studies of Poly(ethylene oxide) based solid-state polymer electrolyte

Abstract

Abstract All-solid-state polymer electrolytes have grown in significance for next-generation energy storage devices because of their high energy endurance, safety, and flexibility. Electrolytes made of poly(ethylene oxide) (PEO) have received a lot of interest because they can dissolve a wide range of ionic salts. We have observed the effects of lithium bis(trifluoromethanesulfonyl)imide salts on the structural, electronic, and thermal properties of solid-state polymer electrolyte systems incorporating PEO using methods based on density functional theory. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) i.e., HOMO-LUMO gap of the PEO and polymer electrolyte are found at 5.74 eV and 3.84 eV, respectively. The value of the HOMO-LUMO gap for PEO and solid-state polymer electrolyte shows similarity with the previous studies. The global and local chemical descriptors are calculated using the HOMO-LUMO gap. The electrochemical stability analysis is performed using the HOMO-LUMO method. Thermal functions also have been studied using density functional theory techniques. The theoretical vibrational frequencies of PEO and solid-state polymer electrolyte are investigated and compared with experimental values.