High electrochemical performance of MnCo2O4.5 nanoneedles/NiCo LDH nanosheets as advanced electrodes of supercapacitor

MnCo2O4.5@NiCo layered double hydroxides (LDHs) are synthesized on nickel foam (NF) using the hydrothermal-calcination-hydrothermal method. It retains MnCo2O4.5 nanoneedles and NiCo LDH nanosheets structures, improving its electrochemical performance. The composite has an excellent specific capacity (1266 C g−1 when current density is 2 A g−1) and deliver an outstanding initial capacity retention (96.8% when current density is 20 A g−1). Moreover, the self-assembled MnCo2O4.5@NiCo LDH/NF//AC (actived carbon) asymmetric supercapacitor (ASC) provides the highest energy density of 33.3 W h kg−1 when the power density is 798 W kg−1 and has a long cycle life of 81% at 5 A g−1 after 7000 cycles. The above results provide a useful strategy for new-generation energy storage devices with excellent properties. [Display omitted] The hydrothermal-calcination-hydrothermal approach is used to effectively construct a needle-sheet nanostructure of MnCo2O4.5@NiCo LDH on nickel foam.