NiCo-layered double hydroxide coating on nitrogen/oxygen co-doped carbon nanocage composite for high-performance supercapacitor electrode

Nickel–cobalt-layered double hydroxide (NiCo-LDH) has received considerable attention in the field of supercapacitor; however, the low conductivity and structural instability limit its practical applications. In this paper, a facile strategy for the fabrication of NiCo-layered double hydroxide (NiCo-LDH) coating on nitrogen/oxygen co-doped carbon nanocages (NOCN) was proposed in this paper. This multicomponent nanocomposite, NiCo-LDH@NOCN, has a high specific capacitance of 1842 F g−1 at 1 A g−1, a remarkable rate capability of 68.1% increasing the current density to 30 A g−1, and excellent cycling stability of 72.1% after 1000 cycles. Furthermore, an asymmetric supercapacitor (ASC) composed of NiCo-LDH@NOCN as a positive electrode and NOCN as a negative electrode was fabricated. The ASC shows a superior energy density of 31.6 Wh kg−1 at a power density of 700 W kg−1, which suggests the great practical application potential of supercapacitor.