Three-Dimensional Flower-Like Ce-Doped NiGa Layered Double Hydroxide for All-Solid-State Asymmetric Supercapacitors

Abstract

Ternary layered double hydroxides are considered ideal electrode materials for high-performance supercapacitors because they have more valence states and higher electrochemical activity than binary layered double hydroxides. Therefore, Ce-doped NiGa layered double hydroxide (Ce–NiGa LDH) loaded on nickel foam (NF) is synthesized by a hydrothermal reaction in this work. Ce–NiGa LDH/NF displays a hybrid morphology of vertically cross-linked nanosheet arrays and microflowers, which has high electrochemical activity. The specific capacitance of 10% Ce–NiGa LDH/NF can reach 1737 F g–1 at 1 A g–1, which is 1.6 times that of NiGa LDH/NF (1077 F g–1 at 1 A g–1). In addition, the assembled 10% Ce–NiGa LDH/NF//activated carbon (AC) all-solid-state asymmetric supercapacitor (ASC) with a poly(vinyl alcohol) (PVA)/KOH gel as the electrolyte shows an energy density of 38.8 Wh kg–1 at the power density of 573 W kg–1. Two ASC devices in series are able to power a red light-emitting diode (LED). As a result, this work provides a thought for the development of the next-generation energy storage device.