Hierarchical design of core–shell structured NiCoAl-LDH composites on rGO/Ni foam with enhanced electrochemical properties for asymmetric supercapacitor
摘要
In this report, 2D hierarchical NiCo-LDH/rGO was fabricated for the purpose of super capacitors. The NiCoAl-LDH nanoplates were affix on the rGO nanosheets, forming a cross-linked core–shell structure. The morphological, textural and elemental composition of the samples was analysed through SEM, BET, XRD, Raman and XPS analysis. The NiCoAl-LDH/rGO composite exhibited the highest specific capacitance of 1916 ± 0.2 Fg−1 at 1 Ag−1 with an excellent cyclic stability of 90.5% over 10,000 charging and discharging cycles at 20 Ag−1. The asymmetric supercapacitor assembled with NiCoAl-LDH/rGO and AC electrodes exhibited a high specific capacitance of 182.5 ± 0.1 Fg−1 at 1 Ag−1 and superior energy density of 59.3 ± 0.2 Whkg−1. The increased conductivity of rGO makes it function faster electrochemically than pure NiCoAl-LDH. SCs may use these materials to hold and transform energy.