Electrochemical preparation, characterization and discharge performance of solid K3Na(FeO4)2

An electrosynthesis from an iron wire gauze in concentrated NaOH electrolyte is first presented for the synthesis of 0.82 M Na2FeO4 solution, and then for the synthesis of solid K3Na(FeO4)2 with purities of 95.3–97.5% and a highest yield of 95%. The synthesis conditions have been explored. The EDX, AAS, FTIR, XRD and electrochemical measurements have been used to characterize the obtained solid sample. Different from K2FeO4 crystals, the synthesized K3Na(FeO4)2 powders exhibit three characteristic IR absorption peaks (787, 801–802 and 858–862 cm−1) and a hexagonal unit cell with the space group P3¯m1 (164). The results of electrochemical experiments show that the K3Na(FeO4)2 electrode has slightly better discharge performance than K2FeO4 one at relatively high discharge currents.