Aqueous Rechargeable Manganese/Iodine Battery

Abstract

Carbon neutralization has promoted the identification of new types of energy storage devices. Aqueous iodine batteries (AIBs) with reversible iodine redox activity are considered a viable candidate for stationary energy storage units and thus have recently drawn extensive research interest. Herein, we introduce an aqueous manganese iodine battery (AMIB), utilizing sodium iodide (NaI) as a redox-active additive in the Mn(ClO₄)₂ (NMC) electrolyte, activated carbon (AC) as a redox host and Mn ions as the charge carrier. Taking advantage of enhanced kinetics facilitated by I₂/2I⁻ redox activity, our suggested AMIBs can be electrochemically charged/discharged with only a 6 % loss in capacity after 2,000 cycles at a low current density of 0.3 A g⁻¹ in an AC||AC coin cell configuration. Moreover, the AC||Zn−Mn hybrid full-cell configuration is also established with AC and a Zn−Mn anode involving the NMC electrolyte, which retains a high energy of 185 Wh kg⁻¹ at a specific power of 2,600 W kg⁻¹. Overall, the AMIBs in this study preferred I₂/I⁻ conversion chemistry, yielding stable cycle stability, rate performance, and low capacity loss per cycle when compared to Manganese Ion Batteries (MIBs) which are based on Mn²⁺ intercalation chemistry.