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In the past two and a half decades, there has been rapid growth in the study of electrochemical supercapacitors. Zinc oxide based electrode materials are proposed for supercapacitor applications because of their less price, ecofriendliness, good electrochemical reversibility, more specific capacitance, etc. In this research work, a set of nanohybrid electrode materials with a composition of Zn 1-x Mg x O 1-δ (where x = 0.1, 0.2, 0.3 and 0.4) has been prepared by a simple chemical precipitation technique. The prepared electrode materials were analyzed by XRD, FTIR, SEM and EDAX. Electrochemical studies, such as cyclic voltammetry, galvanostatic charge-discharge and impedance analysis were carried out in an aqueous electrolyte (1 molL -1 Na 2 SO 4 ) to understand the electrochemical characteristics of the Mg-doped ZnO nanohybrid materials. The findings show that the doping level of Mg in ZnO had an important role in understanding the capacitive behaviors of the materials. Among the four-electrode materials studied, Zn 0.90 Mg 0.10 O 1-δ electrode material exhibits a maximum specific capacitance of 26.33 Fg -1 at a scan rate of 10 mV and hence which may be suitable for electrochemical supercapacitor applications.

In this research work, fine powders of spinel-type LiMn 2-x Ni x O 4-δ (where x = 0.1, 0.2, 0.3, 0.4 and 0.5) as cathode materials for lithium ion batteries were synthesized by combustion synthesis using urea as fuel and metal nitrates as oxidizers at a temperature of 600°C. The physiochemical properties of the prepared cathode materials were investigated by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), particle size analysis, energy dispersive analysis (EDAX) and scanning electron microscopy (SEM). The electrochemical characteristics were studied by impedance spectroscopy. It was found that the physical charactetertistics were moderately influenced because of different dopant (Ni) concentration. Among the samples studied, LiMn 1.9 Ni 0.1 O 4-δ resulted in better electrical conductivity (6.49 x 10-5 Scm-1) at room temperature and hence it may be suitable for lithium ion battery applications.

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