Hydrothermal approach to Co-Ni Layered Double hydroxide: high-performance electrode materials for energy storage devices

In this work, a binder-free Co-Ni layered double hydroxide (Co-Ni LDH) electrode with a distinct flower-like nanostructure was directly deposited on conductive nickel foam via a simple hydrothermal method. Structure, vibration, and electrochemical research were used to analyze the synthesized Co-Ni LDH. Moreover, the electrochemical effectiveness has been evaluated by electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge (GCD), and cyclic voltammetry (CV). The maximum capacitance of the Co-Ni LDH electrode reached 465 F/g with a current of 3 A/g. It also showed good cyclic stability, retaining 89% of its original capacitance following 8000 charge-discharge cycles. A Co-Ni LDH//AC electrode showed high specific capacitance (99.2 F/g at 2 A/g), power density (844 W/kg), and energy density (30.27 Wh/kg). Furthermore, the electrode retained 69.4% of its specific capacitance after a long cycle test (4000) in 3 M KOH solution. The combination of a binder-free design, direct growth, and flower-like nanoarchitecture represents a significant advancement in the development of cost-effective and scalable energy storage materials.