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To meet the demand for high-power-density and long lifespan surpercapacitors (SCs), the Ni–P@Ni HL/CC-1h with a core–shell structure (Ni–P sphere as the core and nanoflake with the Ni and Ni–P heterogeneous layer as shell) was constructed via a facile strategy. The strategy included hydrothermal synthesis of Ni–P spheres with large Ni surface layer on carbon cloth (Ni–P@Ni HL/CC) and subsequent chemical dealloying using HCl as etching solution in order to remove the redundant Ni substances. The morphology, composition, and electrochemical performances of raw Ni–P@Ni HL/CC and the corresponding samples obtained by different dealloying times (0.5, 1, and 2 h) were characterized. Interestingly, the Ni–P@Ni HL/CC-1h presents a unique structure with a nanoflake shell and a porous core, which can provide a large number of exposed active sites, accelerate electrolyte ion diffusion and support ultra-long cycling. Furthermore, the Ni species existing in the outer flake can increase the conductivity and promote the capacitance during the charge–discharge processes. The Ni–P@Ni HL/CC-1h exhibited high specific capacity of 280.8 C g−1 at current density of 1 mA cm−2, high rate retention of 76.2% at 20 mA cm−2. The maximum specific capacity could reach 388.8 C g−1 at 8 mA cm−2, and maintained the 92.6% retention after 3000 cycles. Moreover, the Ni–P@Ni HL/CC-1h//AC all-solid-state asymmetric supercapacitor (ASC) exhibited high specific capacity, 86.0% retention after 10,000 cycles and high energy density of 27.6 Wh kg−1 at power density of 942.8 W kg−1.

Metal-organic frameworks featuring controllable morphologies and tunable compositions and pore structures are widely used as precursors for supercapacitors electrode materials. A zinc/cobalt-based zeolitic imidazolate framework was utilized as a precursor to synthesize N, S-codoped porous carbon supported CoS2 nanocomposites, using a two-step (carbonization and sulfurization) procedure. The as-prepared materials maintained the rhombic dodecahedral structure of the precursors, and carbon nanotubes were rooted onto the nanocomposite surface. The N, S-codoped porous carbon supported CoS2 nanocomposite hybrid electrode exhibited excellent electrochemical performance: high specific capacitance (635.8 F/g at 1 A/g), good rate capability (544.2 F/g at 10 A/g), and long-term cycling stability (88.0% retained after 2000 cycles). Moreover, the energy density of the N, S-codoped porous carbon-supported CoS2 nanocomposites//activated carbon asymmetric supercapacitor reached 14.1 Wh/kg at the power density of 0.71 kW/kg, and its capacitance remained 92.2% after 2000 cycles in the 0–1.4 V potential range.