▎ 摘　　要

The NiAl-layered double hydroxides (NiAl LDHs) has been known as a very desirable positive electrode material for alkaline supercapacitors due to it can provide a higher theoretical specific capacity than beta-Ni(OH)(2). However, NiAl LDHs is structurally unstable in an alkaline solution and can easily convert into another crystal (beta-Ni(OH)(2)). Therefore, it is important to study and design the true active phase of the effective electrode material. In this work, we use high-valence Al ions to replace some of the Ni ions in the raw materials to stabilize its crystal structure and prepare the tremella-like NiAl LDHs decorated on polydopamine/reduced graphene oxide (NiAl LDHs@PDA/rGO) by a simple hydrothermal method. The NiAl LDHs@PDA/rGO exhibit high specific capacitance of 2210.7 F g(-1) at 1 A g(-1) and excellence rate performance (71% of capacitance retention with the increase of current density from 1 to 40 A g(-1)) as the cathode material for supercapacitor. Furthermore, the hybrid supercapacitor delivers a superior energy density of 58.93 W h Kg(-1) at 800.21 W kg(-1) and long cycling life. This work not only provides a simple method to prepare the tremella-like NiAl LDHs@PDA/rGO but also paves the way for the development of advanced cathode materials for the next generation of supercapacitors. (c) 2020 Elsevier B.V. All rights reserved.