Investigations on structural and electrochemical energy storage properties of pH dependent MnWO4 nanoparticles

The electrochemical characteristics of MnWO 4 nanoparticles were engineered via tailoring the pH of the precursor solution during the facile co-precipitation synthesis. The MnWO 4 electrodes were examined for their physicochemical properties using various characterization techniques, wherein the structural study confirms the pure monoclinic crystal structure having a P2/c space group. The electrochemical study confirms the presence of distinct redox peaks during the voltammetry measurements, suggesting efficient intercalation processes. The charge-storage kinetics study confirms that a more complex process than pure diffusion control is involved in electrochemical measurements. The MnWO 4 electrode synthesized at pH 11 exhibited a specific capacitance of 711 F g −1 at a scan rate of 10 mV s –1 , along with a capacitance retention of 90.3% at a scan rate of 100 mV s – 1 . Moreover, the MnWO 4 //AC asymmetric device exhibited a remarkable electrochemical performance, achieving a high energy density of 24.30 Wh kg −1 at a power density of 950 W kg −1 . This study reveals the significant role of pH during the synthesis of nanomaterials, which governs the phase formation, morphological modifications, and electrochemical performance. These results suggest that MnWO 4 is an ideal candidate for advanced energy-storing devices.