Hollow Bowl NiS2@polyaniline Conductive Linker/Graphene Conductive Network: A Triple Composite for High‐Performance Supercapacitor Applications

Abstract The achievement of the outstanding theoretical capacitance of nickel sulfide (NiS 2 ) is challenging due to its low conductivity, slow electrochemical kinetics, and poor structural stability. In this study, we utilize polyaniline (PANI) as a linker to anchor the NiS 2 with a hollow bowl‐like structure, uniformly dispersed at the surface of graphene oxide (GO)(NiS 2 @15PG). The presence of PANI provides growth sites, resulting in a uniform and dense arrangement of NiS 2 . This morphological modulation of NiS 2 increases the contact area between the active material to electrolyte. Additionally, PANI effectively connects NiS 2 with the conductive network of GO, which advances the electrical conductivity and ion diffusion properties. As a result, the R ct (charge transfer resistance) and Z w (Warburg impedance) of NiS 2 @15PG decrease by 82.61 % and 66.76 % respectively. This unique structure confers NiS 2 @15PG with high specific capacitance (536.13 C g −1 at 1 A g −1 ) and excellent multiplicative property of 60.93 % at 20 A g −1 . The assembled NiS 2 @15PG//YP‐50 supercapacitors (HSC) demonstrates an energy density (13.09 Wh kg −1 ) at a high‐power density (16 kW kg −1 ). The capacity retention after 10,000 cycles at 5 A g −1 is 86.59 %, indicating its significant potential for practical applications.