Facile synthesis of the binder-free CoNiMn LTH/nickel foam electrode for high-performance hybrid supercapacitor

The facile synthesis of binder-free electrodes for supercapacitors is crucial, as it provides high electrochemical performance, excellent conductivity, easy manufacturing, and enhanced cycling stability. Layered double hydroxides (LDH) and layered triple hydroxides (LTH) are excellent candidates for achieving these storage characteristics. In this work, binder-free CoNi LDH/nickel foam (NF), CoMn LDH/NF, NiMn LDH/NF, and CoNiMn LTH/NF electrodes were prepared using a facile one-step hydrothermal method. Various characterization techniques were employed to investigate and compare the structural, microstructural, and electrochemical properties. The CoNiMn LTH/NF electrode demonstrated the highest specific capacitance of 2212 F g⁻¹ , attributed to its unique 1D nanoneedle morphology and the synergistic effect of Co, Ni, and Mn elements. The nanoneedle morphology of CoNiMn LTH/NF results in additional diffusion channels and facilitates the penetration of electrolytes. Moreover, the CoNiMn LTH/NF//activated carbon capacitor exhibited battery-type behavior with an energy density of 26.4 Wh kg⁻¹ at a power density of 1397 W kg⁻¹ .