Metal–Organic Framework‐Derived MnO Nanocrystals Embedded in a Spindle Carbon for Rechargeable Aqueous Zinc Battery with a Molten Hydrate Electrolyte
Hongwen Liu, Chih-Yao Chen, Jialong Jiang, Runhao Zhang, Lianli Zou, Yong‐Sheng Wei, Peng Cheng, Qiang Xü, Wei Shi
Abstract
Rechargeable aqueous zinc batteries (RAZBs) are emerging candidates for large‐scale energy storage. However, the lack of high‐capacity cathodes because of the electrostatic interactions between Zn 2+ and cathode and the inferior electronic conductivity restricts their performance. The operating voltage limitation imposed by water is another barrier for RAZBs. Herein, manganese oxide (MnO) nanocrystals embedded in a spindle carbon matrix (MnO@C) synthesized from a metal–organic framework are used as a cathode. The uniform distribution of fine‐sized MnO (≈100 nm) in the carbonized matrix (≈5 μm) and the intimate connection between them not only increase the utilization of electroactive material but also eliminate the use of conductive additive. By utilizing the molten hydrate electrolyte, ZnCl 2 ·2.33H 2 O, a discharge voltage plateau approaching 1.60 V and a high reversible capacity of 106 mAh g −1 after 200 cycles are achieved. This research proposes an approach for affordable RAZBs to fulfill large‐scale energy storage.