Novel dealloying-fabricated NiCo₂S₄ nanoparticles with excellent cycling performance for supercapacitors

In this work, NiCo₂S₄ nanoparticles for supercapacitors are successfully synthesized with a top-down strategy, using a novel dealloying method with an ion exchange reaction. The surface morphology and x-ray diffraction investigations demonstrated that NiCo₂S₄ nanoparticles are interconnected by ligaments of the synthesized sample. The dealloyed NiCo₂S₄ shows an enhanced electrochemical performance of about 1132.5 F g^-1 at 0.5 A g^-1; kinetic analysis implies a surface-controlled contribution from NiCo₂S₄ (53.86% capacitive contributions). Notably, the NiCo₂S₄//AC (active carbon) device displays a comparatively high energy density (22.83 Wh kg^-1), maximum power density (1327.1 W kg^-1) and superior cycling performance (capacitance retention of 108% after 30 000 cycles).