Rational design and facile synthesis of Ni-Co-Fe ternary LDH porous sheets for high-performance aqueous asymmetric supercapacitor

Abstract

Reasonable construction of microstructure and successful combination of multiple components provide an extensible strategy for the exhibition of electrode materials in asymmetric supercapacitors (SCs). Lately, transition-metal-based ternary layered double hydroxides (LDHs) have evoked substantial focus in the area of supercapacitor by reason of their excellent features such as tunable chemical composition and a high electro-chemical competence. In order to make certain the impact of metal proportion on electrochemical performance of LDHs, herein, two-dimensional porous NixCo1-xFe-LDHs (NixCo1-xFe-LDH, x = 0, 0.25, 0.75, 1) nanosheets are synthesized by a succinct-operated hydrothermal method to employ in high energy density hybrid supercapacitor (HSC). The molar ratio of NiCoFe-LDH compounds is regulated and researched the difference of structural, morphological, and electrochemical properties by the numbers, subsequently compared with their binary counterparts. Here we demonstrate that the higher the nickel content is, the higher the specific capacity is of LDH so that NiCoFe-LDH product renders a large capacitance of 425.56 mAh·g−1 at a current density of 1 A·g−1 with 94.52% capacitance retention observed at 10 A·g−1. Moreover, the trimetallic CoNiFe-LDH are more effective in boosting the SCs performance than the two sets of bimetallic LDHs. An aqueous HSC device is composed of NiCoFe-LDH and activated carbon (AC) which displays a high energy density (51.82 Wh·kg−1) at a power density of 1.26 kW·kg−1 with outstanding cycle stability (95.16 % after 10,000 cycles). The excellent NiCoFe-LDH electrode material is hopeful for high-property SCs.