Development of iodate-based high oxidation state cathode for aqueous battery system

• Published in: Materials chemistry and physics 2021-11, Vol.273, p.125070, Article 125070
• Main Authors: Wang, Zhiqian, Di Benedetto, Giuseppe L., Zunino, James L., Mitra, Somenath
• Format: Article
• Language: English
• Subjects: 3D printing; Anion exchange membrane; Aqueous battery; Cathodes; Chemical precipitation; Discharge; Electrode materials; Electrolytes; Iodate; Lead; Oxidation; Primary batteries; Reaction products; Redox reactions; Saline water; Three dimensional printing; Valence
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.125070

We present the synthesis of lead iodate (Pb(IO3)2) using precipitation reactions for the fabrication of cathodes. Pb(IO3)2-Zn reserve batteries are fabricated in 3D-printed battery casings. Pb(IO3)2-nano carbon composites show higher stability and more consistent performance than the mixtures of these compounds. The reaction products and cell performances are dependent on electrolytes and discharge rates. These primary batteries exhibit an output voltage around 1.6 V when acid-salt water dual electrolytes are used. At low discharge rates, the iodate gets reduced to I2, yet under high-rate discharge, PbI2 is produced. The cathode material Pb(IO3)2 hence demonstrates specific capacities between 416 and 550 mAh g−1. Only the IO3− takes part in the redox reactions and provides the capacity. Hence, Pb could be replaced with other metals, and the chemistry here could be applied to other insoluble iodate salts for environmental concerns and lower costs. [Display omitted] •Lead iodate-zinc batteries have been developed.•Pb(IO3)2 goes through a 5-electron reduction to I2 at low discharge rates.•At a fast discharge rate, Pb(IO3)2 is reduced to PbI2 via a 6-electron process.•Pb(IO3)2 shows specific capacities of 416–550 mAh g−1 at low to high discharge rates.•Incorporation of nano-carbon in Pb(IO3)2 further improved performance.