Synthesis and characterization of zinc-thiocyanato and chromium(III)-quinoline complex as K-ion battery material

Potassium ion-based batteries have potential as cathode for replacement lithium-ion battery. Prussian Blue-Like (PBL) compounds are one of a candidate for potassium ion battery. In this study, we synthesized the PBL compound using zinc chloride, quinoline, chromium(III) chloride, and potassium thiocyanate with a mole ratio of 1:2:1:6 and as well as the characterization of the complex compound as material for Potassium Ion Battery (PIB). As-synthesized compound was formed dark-greenish purple crystals, which melt at 182-185 degrees C. The UV-Vis characterization indicates the presence of Cr3+ ion. The as-synthesized structure formula, K[Cr(C9H7N)(2)(SCN)(2)][Zn(SCN)(4)], was indicated by using XRD and SEM-EDX analysis. The presenting of quinoline and thiocyanate as ligands were identified from the as-synthesized FT-IR spectra. Its reduction potential showed the potential properties as battery material up to 0.45 V.