Hierarchical Ni–Mn layered double hydroxide grown on nitrogen-doped carbon foams as high-performance supercapacitor electrode

Abstract

Hierarchical Ni–Mn Layered Double Hydroxide (Ni–Mn LDH) nanosheets grow on a nitrogen-doped carbon foam skeleton through a one-step hydrothermal reaction. LNCF-2 exhibits high specific capacitance (2128.3 F g−1 at 0.5 A g−1) and good cyclic stability (94.3% retention after 5000 cycles at 2 A g−1) as an electrode material for supercapacitors. Furthermore, as a positive electrode material for an asymmetric supercapacitors (ASCs), it also has a high specific capacitance (125.1 F g−1 at 0.5 A g−1) and an excellent cyclic stability (80.1% retention after 10000 cycles at 5 A g−1). The increase in electrochemical performance is attributed to the high Faradaic pseudocapacitance of Ni-Mn LDH and the introduction of three-dimensional carbon foam. Because the introduction of three-dimensional carbon foam can provide an interconnection network for electron and ion transfer, allowing efficient charge exchange.