A Long Cycle Life, Self-Healing Zinc-Iodine Flow Battery with High Power Density

摘要

A zinc-iodine flow battery (ZIFB) with long cycle life, high energy, high power density, and self-healing behavior is prepared. The long cycle life was achieved by employing a low-cost porous polyolefin membrane and stable electrolytes. The pores in the membrane can be filled with a solution containing I-3(-) that can react with zinc dendrite. Therefore, by consuming zinc dendrite, the battery can self-recover from micro-short-circuiting resulting from overcharging. By using KI, ZnBr2, and KCl as electrolytes and a high ion-conductivity porous membrane, a very high power density can be achieved. As a result, a ZIFB exhibits an energy efficiency (EE) of 82% at 80mAcm(-2), which is 8times higher than the currently reported ZIFBs. Furthermore, a stack with an output of 700W was assembled and continuously run for more than 300cycles. We believe this ZIFB can lead the way to development of new-generation, high-performance flow batteries.