The future of energy storage systems requires high energy and power capabilities, particularly for electronics and electric vehicles. This study presents copper tungstate (CuWO4) nanocrystals synthesized via a coprecipitation method and post-heat-treated at 500 ºC for 2 hours. X-ray diffraction patterns and Rietveld refinement data showed that the CuWO4 nanocrystals are monophasic with a triclinic structure, featuring distorted octahedral [CuO6] and [WO6] clusters. Spectroscopic analyses, including micro-Raman and Fourier transform infrared, identified multiple vibrational modes, while X-ray photoelectron spectroscopy confirmed the presence of Cu 2p, W 4f, and O 1s electronic states. Optical bandgap measurements showed an energy value of 2.48 eV. Scanning electron microscopy indicated the formation of aggregated, quasi-spherical nanocrystals. The Ni-foam|CuWO4 electrode present a high specific capacitance of 954.6 Fg-1 at 0.3 Ag-1 at 1240.1 Fg-1 at 5 mVs-1 measure through by galvanostatic chargedischarge and cyclic voltammetry and retention close to 97% after 5,000 cycles. Finally, Nyquist plots were obtained, and a good capacity of mass transport can be retained well after 5,000 cycles with the typical behavior of intrinsic ohmic and charge transfer resistances. The Ragone plots were obtained, showcasing impressive parameters of power density and energy density, with maximum values of 809.9 WKg-1 and 96.66 WhKg-1, respectively.
