Contribution of stilbene-imine additives on the structural, ionic conductivity performance and theoretical evaluation...

New solid biopolymer electrolytes (SBEs) were prepared by integrating stilbene-imine derivatives bearing vinylene (CHCH) and azomethine (CHN) as additives in carboxymethyl cellulose (CMC) based electrolyte. The investigation on their spectroscopic and theoretical assessments were conducted to alter the energy level in improving the structural and ionic conductivity performance. The simulated results from frontier molecular orbitals (FMO) and Mulliken-charge analysis revealed that -CF₃ and -NO₂ substituents significantly reduce the HOMO-LUMO gap up to 0.68 eV. The highest ionic conductivity of SBEs achieved at ambient temperature was ∼8 × 10^-3 Scm^-1 upon the addition of additive, obeying an Arrhenius model with reciprocal of temperature (303 K-373 K). The coordination interaction of CO bond and CHN band facilitated the dissociation of more cation (H⁺) of NH₄Cl which permits alternative route for H⁺ to hop into coordinating site in CMC. The outcomes are ideal in the development of electrochemical devices.