Development of chitosan-based polymer electrolyte membrane from blood clam (Anadara granosa) shells with KCl and PVA/PAN blend polymers

• Chitosan-based polymer electrolytes were developed from blood clam shells. • The highest ionic conductivity achieved was 0.0437 S/cm at optimal composition. • KCl enhanced mechanical stability, with peak tensile strength at 8.77 MPa. • FTIR and SEM confirmed KCl integration and its effect on membrane morphology. • The hybrid conductivity mechanism shows promise for sustainable biobatteries. The increasing reliance on renewable energy sources necessitates efficient and sustainable energy storage technologies, with batteries playing a crucial role in this transition. However, conventional batteries, particularly dry cell batteries, pose environmental concerns due to hazardous waste, which highlight the urgent need for biodegradable alternatives such as biopolymer-based electrolytes to reduce environmental impact and promote sustainable energy storage solutions. This study focuses on developing chitosan-based polymer electrolyte membranes from blood clam ( Anadara granosa ) shells combined with PVA/PAN blend polymer and KCl. The research process involved preparing blood clam shells of chitosan and fabricating chitosan/PVA/PAN/KCl polymer electrolyte membrane. The analysis included ionic conductivity analysis, mechanical properties, morphological, and functional group characterization of the membrane. The results of highest ionic conductivity measurement was 4.37×10 -2 S/cm, corresponding to a bulk resistance (R b ) of 0.18 Ω, with PVA/PAN ratio of 30:70, a chitosan content of 3.0 g and KCl of 1.2 g. Additionally, tensile strength analysis showed that KCl incorporation enhanced mechanical stability, with the highest tensile strength (8.77 MPa) and Young’s modulus (114.64 MPa) obtained at KCl of 1.2 g. Elongation at break initially increased with KCl addition, peaking at 11.88% at 0.8 g KCl, before decreasing at higher concentrations, indicating a trade-off between flexibility and mechanical rigidity. Structural analysis using FTIR spectroscopy confirmed the successful integration of KCl, while SEM imaging provided visual evidence of its distribution and impact on membrane morphology. The high ionic conductivity of this chitosan-based PEM likely stems from a hybrid mechanism of KCl-driven vehicle diffusion and proton hopping, indicating strong potential for sustainable energy storage, though further optimization is required for commercial biobattery applications.