Stable neodymium gallium oxide (Nd 3 Ga 5 O 12 and Nd 3 GaO 6 ) phases: a study on their asymmetric supercapacitor applications

Rare-earth-based nanomaterials with exceptional electrochemical properties can be obtained a simple, low-cost, environment-friendly citrate-gel-matrix approach. Owing to their high specific capacitance, strong conductivity, and electrochemical stability, gallium-based materials are capable of withstanding numerous charge-discharge cycles, thus extending the life cycle of a supercapacitor. This tunability enabled researchers to alter the morphology and composition of the electrode to enhance supercapacitor performance. This research describes the investigation of stable neodymium gallium oxides, namely, Nd Ga O and Nd GaO , synthesised a citrate-gel-matrix method for asymmetric supercapacitor applications. Structural, morphological and optical studies elucidated the outstanding supercapacitor performance of Nd Ga O and Nd GaO . XRD revealed the formation of cubic Nd Ga O and orthorhombic Nd GaO . The vibrational modes, optical properties, surface morphology and oxidation states of Nd Ga O phases were examined using Raman spectroscopy, UV-visible spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Electrochemical studies using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy revealed that the fabricated Nd Ga O electrode resulted in a greater specific capacitance of about 418 F g than Nd GaO , thereby displaying superior electrochemical characteristics. An asymmetric device fabricated with Nd Ga O demonstrated a specific capacitance of about 64 F g , energy density of 20 W h kg and a power density of about 750 W kg . Thus, the favorable attributes of Nd Ga O in terms of its electrochemical performance indicate its significant promise for potential application in energy-storage devices.