Structural Transformation by Crystal Engineering Endows Aqueous Zinc‐Ion Batteries with Ultra‐long Cyclability
Kangning Wang, Jianwei Wang, Peiming Chen, Mengran Qin, Chunming Yang, Wenlin Zhang, Zhuangzhuang Zhang, Yanzhong Zhen, Feng Fu, Bin Xu
Abstract
Abstract Manganese oxide is a promising cathode material for aqueous zinc batteries. However, its weak structural stability, low electrical conductivity, and sluggish reaction kinetics lead to rapid capacity fading. Herein, a crystal engineering strategy is proposed to construct a novel MnO 2 cathode material. Both experimental results and theoretical calculations demonstrate that Al‐doping plays a crucial role in phase transition and doping‐superlattice structure construction, which stabilizes the structure of MnO 2 cathode materials, improves conductivity, and accelerates ion diffusion dynamics. As a result, 1.98% Al‐doping MnO 2 (AlMO) cathode shows an incredible 15 000 cycle stability with a low capacity decay rate of 0.0014% per cycle at 4 A g −1 . Additionally, it provides superior specific capacity of 311.2 mAh g −1 at 0.1 A g −1 and excellent rate performance (145.2 mAh g −1 at 5.0 A g −1 ). To illustrate the potential of 1.98%AlMO to be applied in actual practice, flexible energy storage devices are fabricated and measured. These discoveries provide a new insight for structural transformation via crystal engineering, as well as a new avenue for the rational design of electrode material in other battery systems.