Development of High Areal Capacity Electrolytic <scp>MnO<sub>2</sub>–Zn</scp> Battery via an Iodine Mediator
Xinhua Zheng, Ruihao Luo, Touqeer Ahmad, Jifei Sun, Shuang Liu, Na Chen, Mingming Wang, Yuan Yuan, Mingyan Chuai, Yan Xu, Taoli Jiang, Wei Chen
Abstract
The commercialization of electrolytic MnO 2 –Zn batteries is highly applauded owing to the advantages of cost‐effectiveness, high safety, high energy density, and durable working performance. However, due to the low reversibility of the cathode MnO 2 /Mn 2+ chemistry at high areal capacities and the severe Zn anode corrosion, the practical application of MnO 2 –Zn batteries is hampered by inadequate lifespan. Leveraging the full advantage of an iodine redox mediator, here we design a highly rechargeable electrolytic MnO 2 –Zn battery with a high areal capacity. The MnO 2 –Zn battery coupled with an iodine mediator in a mild electrolyte shows a high discharge voltage of 1.85 V and a robust areal capacity of 10 mAh cm −2 under a substantial discharge current density of 160 mA cm −2 . The MnO 2 /I 2 –Zn battery with an areal capacity of 10 mAh cm −2 exhibits prolonged stability of over 950 cycles under a high‐capacity retention of ~94%. The scaled‐up MnO 2 /I 2 –Zn battery reveals a stable cycle life under a cell capacity of ~600 mAh. Moreover, our constructed MnO 2 /I 2 –Zn battery demonstrates a practical energy density of ~37 Wh kg −1 and a competitive energy cost of <18 US$ kWh −1 by taking into account the cathode, anode, and electrolyte. The MnO 2 /I 2 –Zn battery, with its remarkable reversibility and reasonable energy density, enlightens a new arena of large‐scale energy storage devices.