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• The NiCoS@NiMo-LDH hierarchical composites are synthesized on Ni foam. • NiCoS@NiMo-LDH nanostructure provides abundant active sites and enough ion channels. • The binder-free NiCoS@NiMo-LDH electrode exhibits excellent electrochemical properties. • The fabricated ASC device exhibits a high energy density and good stability. Ni(OH) 2 ·0.75H 2 O nanosheets embedded with NiMoO 4 nanoparticles (NiMo-LDH) supported by nickel cobalt sulfur (NiCoS) nanorods were prepared by a multi-step hydrothermal method, which provides an effective channel for ion transport and abundant active sites for charge storage. The NiCoS@NiMo-LDH electrode exhibited a very high capacitance of 1302.5 μAh cm−2 at 10 mA cm−2, with 54 % capacitance retention observed at 50 mA cm−2. The asymmetric supercapacitor (ASC) assembled with the NiCoS@NiMo-LDH as the positive electrode and active carbon (AC) as the negative electrodes which exhibits an energy density of 1096.6 μWh cm−2 at a power density of 2.8 mW cm−2 along with good stability of 86.67 % after 5000 cycles. [ABSTRACT FROM AUTHOR]

• The controllable synthesis of nano-hexahedron porous carbon was obtained. • The capacitance retention of nano-hexahedron porous carbon is up to 100% at 5 A g−1 after 10,000 cycles. • The symmetrical supercapacitor exhibits a high energy density of 9.04 Wh kg−1 at a power density of 350 W kg−1. The nano-hexahedron porous carbon was prepared by directly carbonizing a Zn-based zeolitic imidazolate framework (ZIF-8) at designed temperatures. After carbonization, the nano-hexahedron porous carbon shows a large specific surface area of 1142 m2 g−1 at a pore diameter of approximate 3 nm, a high capacitance of 187 F g−1, a remarkable rate-capability of 75.9%, and an unchangeable capacitance retention after 10,000 cycles. Furthermore, the symmetrical supercapacitor exhibits a high energy density of 9.04 Wh kg−1 at a power density of 350 W kg−1 and a notable capacitance retention of 80.2% after 5000 cycles. All results have suggested that the nano-hexahedron porous carbon is adaptable to the assembly of effective electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]