Empowering Green Energy: ί-Carrageenan Based Solid Polymer Electrolytes for Zinc Ion Batteries

This work investigates the potential of ί-carrageenan, a natural biopolymer, doped with zinc trifluoromethanesulfonate (Zn(Tf)₂) (or zinc triflate), to serve as a solid polymer electrolyte (SPE) films for zinc ion conducting batteries (ZIBs). The solution casting technique is employed to prepare the electrolyte films. The study focuses on examining the impact of the dopant and its concentration on the electrochemical properties of the polymer. The research verifies the effectiveness of this SPE by incorporating it into a Zn/MnO₂ primary cell. The results show that the cell achieved an initial open-circuit voltage (OCV) of 1.55 V and an initial short-circuit current (SCC) of 1 mA. Furthermore, the SPE demonstrated a conductivity of 10⁻⁵ S cm⁻¹, which is two orders higher than the undoped polymer. This significant improvement in conductivity highlights the potential of ί-carrageenan doped with zinc triflate as SPE for ZIBs.