Exploration of Prussian Blue Analogs electrodes for aqueous system

Aqueous rechargeable batteries are promising alternatives to lithium-ion systems due to their high safety, low cost, and environmental compatibility. In this thesis, Prussian blue analogue cathode materials were investigated for aqueous battery applications, focusing on copper hexacyanoferrate (CuHCF) and mixed-metal copper–zinc hexacyanoferrate (Cu–Zn HCF). Both materials were synthesized through a controlled aqueous co-precipitation method and characterized using SEM/EDX, FTIR, and thermal analyses (TGA/DTG/DSC) to evaluate morphology, composition, and thermal stability. Electrochemical performance was studied by cyclic voltammetry in aqueous zinc-based electrolytes. CuHCF showed reversible redox activity associated with the Fe²⁺/Fe³⁺ couple, confirming its suitability as a cathode. The Cu–Zn HCF analogue exhibited improved structural uniformity and a stronger electrochemical response, with sharper redox features and better stability under different scan rates and potential windows. Overall, the results indicate that CuHCF-based PBAs, especially the mixed-metal system, are promising cathode materials for safe and scalable aqueous rechargeable batteries.