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.