Boosting the charge storage capability of Ni foams via femtosecond laser structuring in different solvents

The current energy crisis and increasing demand for energy questions to develop new and advanced electrode materials to address this global challenge. Enhancing the capabilities of current collectors can significantly improve the performance of both established and newly developed electrode materials. For this purpose, femtosecond laser technology offers a promising approach to boost the charge storage capacity of electrodes by increasing surface area and porosity. In this study, we utilized an ultrafast femtosecond laser (fs) ablation method to structure nickel (Ni) foam, a common current collector material, in different solvents such as deionized water and acetone. The formed micro/nanostructures on the surface of the ablated Ni foams led to improved surface properties, and these samples were used as a current collector for supercapacitor applications. We investigated the impact of the structural, morphology and elemental compositions of the fs-laser ablated Ni foams on their electrochemical properties. Our findings reveal that the femtosecond laser ablated sample in acetone demonstrates the lowest resistance to internal charge transfer and the highest specific capacitance values, achieving 466.01 mF/cm² at a scan rate of 2 mV/s and 509.45 mF/cm² at a current density of 1 mA/cm². This approach of using femtosecond laser-treated Ni foam as a current collector can enhance the charge storage capacity of supercapacitors when combined with various nanomaterials as electrode active materials.