Enhanced capacitive performance in hybrid supercapacitors via synergistic co(OH)2/Ni2Co(PO4)2 composite nanomaterials

We introduce Co(OH)₂/Ni₂Co (PO₄)₂ composite nanomaterials, synthesized via hydrothermal synthesis, as potential high-stability cathode materials for hybrid supercapacitors (HSCs). Structural characterization tests, such as XRD, SEM, HRTEM, and XPS, revealed the subtleties of the morphology, structure, and composition of these nanostructures. The electrode material exhibits an ultra-high capacitance of 2131.2 F g −1 at 1 A g −1 . When combined with activated carbon (AC), the resulting HSC exhibits a high capacitance of 123.2 F g −1 and remarkable cycle life, with 94.6 % capacitance retention after 12,000 cycles. The device achieves an energy density of 39.5 Wh kg −1 at 750 W kg −1 . This study meticulously details the synthesis, structural characterization, and extensive electrochemical analysis, culminating in their effective application in HSCs.