Impact of Ammonium Triflate on Iota Carrageenan Solid Biopolymer Electrolytes for Electrochemical Devices

Abstract

A free-standing, flexible polysaccharide-based natural solid polymer electrolyte composed of i-Carrageenan doped with various concentrations of ammonium triflate is created via the solution casting approach. An investigation was conducted into the effects of ionic dopant on the structural, vibrational, thermal, dielectric, transport, and electrochemical properties of created solid polymer electrolyte. Structural analysis (X-ray difraction and Fourier transform infrared spectroscopy) proves the non-crystalline nature and the interaction between dopant salt and biopolymer. The maximum conductivity of 1.27 × 10⁻³Scm⁻¹ is achieved for the sample containing 1 g i-Carrageenan and 0.3 wt% of ammonium triflate. Dielectric studies reveal that highest conducting membrane shows maximum ε′ and ε″ values. Thermal studies indicate that low glass transition temperature of 28 °C for the highest conducting membrane. Primary proton battery and single polymer electrolyte membrane fuel cell with the highest conducting membrane were fabricated, and their properties are examined. Open-circuit voltages of proton battery and fuel cell are observed to be 1.03 V and 631 mV, respectively.