Ultrafast Co0.8Al0.2-Layered Double-Hydroxide Nanosheets Cathode for High-Performance Co-Zn Battery

Developing cathode materials of high capacity and rapid rate ability is crucial to aqueous Zn-based batteries. Herein, we demonstrate Co0.8Al0.2-layered double hydroxide (LDH) nanosheets arrays as powerful cathodes for advanced Co-Zn batteries. Benefitting from the ultrathin nanosheets morphology and the large interlayer space LDH structure, both the electrochemical activity and the OH--diffusion kinetics are boosted. As a result, the Co0.8Al0.2-LDH exhibits outstanding electrochemical properties with a high capacity of 318 mAh g(-1) and robust rate ability (74.5% of the capacity maintained at 64.8 A g(-1)). Furthermore, the Co0.8Al0.2-LDH cathode is employed to fabricate a Co0.8Al0.2-LDH//Zn battery, which achieves an impressive energy density of 392.9 Wh kg(-1) (based on the total active mass), and still maintains 264 Wh kg(-1) at a record high power density of 75.7 kW kg(-1) together with a long lifespan (96% capacity maintained after 8000 cycles), which surpasses almost all of the currently reported Ni/Co-Zn batteries. This ultrafast and high-capacity Co0.8Al0.2-LDH cathode is promising for progressive aqueous Zn-based batteries.