SiC-induced modification of MnCo₂O₄ nanoneedles fabricated on Ni foam for binder-free electrodes in high-performance asymmetrical supercapacitors

Supercapacitors with large energy densities are required for commercial applications. Herein, the urchin-like and hexagonal MnCo₂O₄/SiC composite is prepared in situ on Ni foam. The urchin-like MnCo₂O₄/SiC consists of nanoneedle clusters with a length of about 10 μm and a diameter of 20 nm. The MnCo₂O₄/SiC||AC asymmetrical supercapacitor (ASCs) shows an energy density of 90.3 Wh/kg (1.73F cm⁻²) at a power density of 1.25 kW/kg together with 92.1 % retention of the specific capacitance after 10,000 cycles. The results reveal excellent properties and large commercial potential. © 2024 Elsevier B.V.