High-Performance Lithium-Iodine Flow Battery

Abstract

A cathode-flow lithium-iodine (Li-I) battery is proposed operating by the triiodide/iodide (I-3(-)/I-) redox couple in aqueous solution. The aqueous Li-I battery has noticeably high energy density (approximate to 0.28 kWh kg(cell)(-1)) because of the considerable solubility of LiI in aqueous solution (approximate to 8.2 m) and reasonably high power density (approximate to 130 mW cm(-2) at a current rate of 60 mA cm(-2), 328 K). In the operation of cathode-flow mode, the Li-I battery attains high storage capacity (approximate to 90% of the theoretical capacity), Coulombic efficiency (100% +/- 1% in 2-20 cycles) and cyclic performance (>99% capacity retention for 20 cycles) up to total capacity of 100 mAh.