Structure and Electrochemical Properties of Laser-Modified NiWO<sub>4</sub>

In recent years, nickel tungstate has attracted considerable research interest as an electrode material for supercapacitors. In this work, NiWO4 was synthesized by co-precipitation and exposed to laser irradiation. The structure of nickel tungstate was investigated by X-ray diffraction and its electrochemical properties by potentiodynamics, galvanostatic and impedance spectroscopy methods. The results show that NiWO4 subjected to laser irradiation for 180 s showed higher specific characteristics than the initial material. Namely, at a discharge current of 1 mA, NiWO4 achieves a specific capacitance of 153 F/g, and this value is 48% higher than that of the initial material. The higher specific characteristics of laser-modified NiWO4 result from the ability of the material to interact better with electrolyte ions due to the passage of fast redox reactions and the capacitance of the electrical double layer, which is confirmed by impedance studies.