A novel interlaced NiCoFe hydrotalcite assembled by nanorods and nanosheets with enhanced electrochemical performance for supercapacitor

Abstract

Layered double hydroxide (LDH) has attracted extensive attention as the potential electrode materials used in asymmetric supercapacitor (ASC) because of its adjustable elemental composition and microstructure. In this work, a series of NiCoFe-LDH with different element ratios and morphology was synthesized by a facile hydrothermal treatment. A special interlaced structure assembled by nanorods and nanosheets surprisedly emerged. The nanorods and nanosheets have same chemical composition. The corresponding NiCoFe-LDH with interlaced structure exhibits much excellent electrochemical performance than that with single structure. Especially, the Ni₂Co₁Fe₁-LDH material has the highest specific capacitance of 1772.26 F g⁻¹ at 1 A g⁻¹ due to the suitable specific surface area and pore structure, faster electron transportation and dynamic Faradaic redox reactions. The Ni₂Co₁Fe₁-LDH//AC ASC based on the Ni₂Co₁Fe₁-LDH and active carbon (AC) reveals a better specific capacitance of 256.19 F g⁻¹ at 1 A g⁻¹ and an excellent energy density of 91.09 Wh kg⁻¹ at the power density of 809.68 W kg⁻¹. The change of metal element proportion effectively adjusted the interlaced structure of NiCoFe-LDH and extremely enhanced the electrochemical performance of the resulted electrode materials.