Author: Mikael Unge
Title: Electronic structure of amorphous poly(ethylene oxide)
Poly(ethylene oxide) (PEO) has been extensively studied with focus on usage as polymer electrolyte in solid state battery applications. Primarily Li ion conduction in PEO has been studied in the literature, but as the polymer electrolyte become thinner, to facilitate ion conduction, electronic leakage currents may be of increasing importance. Here we focus on electronic structure properties which will be of relevance for understanding electronic leakage currents in PEO. PEO is a semi crystalline material and here we focus on the amorphous part. Amorphous structures are generated and relaxed using molecular dynamics and electronic structure is calculated using linear-scaling DFT. First results indicate that the conduction states are inter chain states and occupies free volume pockets. Mobility edges are calculated for holes and electrons at 0 K and estimated to be 0.5 eV and 0.8 eV away from the band edges, respectively. At room temperature and 80 degC, these shift to 0.1 eV and 0.3 eV, respectively.