Solid electrolyte system compared to a liquid electrolyte is desirable for some electrochemical applications. Natural polymers like polysaccharides were explored as polymer matrix in the development of solid electrolyte system. Among the polysaccharides screened, k-carrageenan showed promising results. Cyclic voltammetry of the I3
-/I- redox couple in k-carrageenan gel showed improved performance compared to aqueous medium. Composite films of k-carrageenan with KI and I2 as triiodide sources and polymer electrolytes based on k-carrageenan and ionic liquid, 1,3-dimethyl imidazolium iodide (DMII) with I2 were prepared and characterized. The composite characterizations indicate that lower conductivity using Van der Pauw technique was observed with KI/I2 system owing to its porous surface. The k- carrageenan/DMII/I2 system on the other hand showed a smooth surface and significantly higher conductivity making it a promising solid electrolyte system.
Solid electrolyte, Carrageenan, ionic liquid