A DFT Based Investigation of Structural and Optoelectronic Properties of Solid Polymer Electrolyte LiFSI Complexes

Computational tools for studying the atomic and molecular structures of complex systems are very useful. This work uses the first principle method to investigate the structural and optoelectronic properties of a polyethylene oxide (PEO)-based solid polymer electrolyte including lithium salt (LiFSI) as an ion-conducting species. DFT has been used for the analysis of electrolyte conducting properties. The electrical band gap of the polymer electrolyte (PEO)8-LiFSI system has been quantitatively examined by density of states (DOS) studies. From electronical analysis, it is verified that (PEO)8 exhibits insulator properties with a wide band gap of 6.2797 eV, whereas the bandgap of (PEO)8-LiFSI slightly drops to 6.0028 eV. These findings suggest that the current polymer electrolyte system (PEO)8-LiFSI could be a viable option for the electrolyte in next-generation energy storage devices.