Fluffy Cotton-Like GO/Zn–Co–Ni Layered Double Hydroxides Form from a Sacrificed Template GO/ZIF-8 for High Performance Asymmetric Supercapacitors

The combination of carbon materials and active metal materials can prepare newly fashioned and hierarchical porous materials. Meanwhile, the combined action of the two materials can effectively optimize the performance of electrode materials. The electrode material GO/Zn–Co–Ni layered double hydroxides (LDHs) (abbreviated as GO/ZCN) with a fluffy cotton-like structure is prepared via sacrificing the template GO/ZIF-8, showing a combination of carbon materials (GO) and triple hydroxides (Zn–Co–Ni LDHs). ZIF-8 easily solves the agglomeration of Zn–Co–Ni LDHs by discarding its own dodecahedral structure. The GO/ZCN exhibits a 843.0 C g–1 high specific capacitance, while the current density is 1 A g–1. We can also utilize compressed GO/ZCN to acquire striking cycling stability (97.71% capacitance retention at 10 A g–1 at the end of 5000 charge–discharge circulations) which is improved greatly compared to uncompressed GO/ZCN. The supercapacitor device of GO/ZCN//activated carbon (AC) displays an excellent energy density (64.91 Wh kg–1), while the power density is 800 W kg–1, and a good cycling stability performance (a specific capacitance retention of 98.96% is obtained after 10,000 charge–discharge cycles). Two fully charged and connected GO/ZCN//AC ASC devices can have three different colored LEDs (light emitting diodes) sparkle at the same time and make a red LED glow for at least 50 min, showing a good practical application effect.