Development of high-capacity flexible sodium manganese periodate batteries with dual polymer electrolytes

We present the development of a dual-electrolyte, flexible battery based on sodium manganese periodate-zinc system. H₃PO₄-KCl quasi-solid dual electrolytes separated by an anion-exchange-membrane maintained the desired pH at electrodes and blocked unwanted ion movements. Poly(acrylic acid) based quasi-solid electrolytes were optimized to fortify the electrodes, increase electrode flexibility, eliminate free-flow liquids, and enhance battery performance. Anode electrolyte pH adjustment enhanced ionic conductivity and reduced zinc corrosion. The nano-grade NaMnIO₆ showed a specific capacity of 650 mA h g⁻¹, approximately 81 % of its theoretical capacity even when cells are bent. The capacity reported here is at least 80 % higher than other flexible battery reported before.