A binder-free copper sulfide cathode material for aluminum-ion batteries

This work realizes the fabrication of binderless cathode for aluminum ion batteries, the most promising alternative energy storage technology of next-generation batteries. The hypothesis is to test the concentration of urea on the morphology of copper sulfide particles grown on a nickel foam via hydrothermal synthesis for Al-ion batteries. In this context, the hydrothermal approach has been effectively employed for depositing cathode active material (CAM), copper sulfide, directly on a Ni foam, the current collector. Four distinct samples have been produced at varying urea ratios (CS-4 (4 mmol), CS-8 (8 mmol), CS-12 (12 mmol), CS-24 (24 mmol)) for the first time in the literature. The impact of the urea concentration on the CAM's morphology and structure has been assessed using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS). Their electrochemical performances have been evaluated based on the potentiostatic (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS)), and galvanostatic (charge/discharge tests) tests results. CS-12 made by 12 mmol of urea, has high crystallinity and flower-like morphology with flakes, it delivers the best electrochemical performance with 69 mAh/g after 100 cycles under a current load of 200 mA g⁻¹.