INVESTIGATION OF ELECTROCHEMICAL CHARACTERISTICS of α-NaxMnO2 CATHODES FOR SODIUM-ION BATTERIES

Abstract

P2 and O3 layered structure materials have large potential for application as cathodes for sodium-ion batteries. This article presents the research results on the electrochemical properties of layered structure α-NaxMnO2 (x = 0.7-1.0) cathode materials synthesized via the sol-gel method. The α-NaxMnO2 cathode materials were characterized by X-ray diffraction (XRD) to determine their crystal structure, scanning electron microscopy (SEM) to analyze their morphology, and energy-dispersive X-ray spectroscopy (EDX) to assess their elemental composition. The electrochemical properties of α-NaxMnO2 materials were investigated using CR2032 coin cells, in which the cathodes were fabricated from the synthesized α-NaxMnO2 materials. The α-NaxMnO2 cathode material exhibited the highest initial charge-discharge capacity at a rate of 0.1 C when x = 1.0, with values of 168.43 mAh.g-1 and 165.18 mAh.g-1 in the first cycle, respectively. However, the capacity declined significantly after 10 cycles and reached only about 50.02% of its initial value after 50 cycles. The composition with the highest cycling stability was Na0.8MnO2 (x = 0.8), maintaining 63.37% of its initial capacity after 50 cycles. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were conducted using an Ivium potentiostat to evaluate the electrochemical properties of the synthesized materials. The α-NaxMnO2 material demonstrates strong potential as a cathode candidate for sodium-ion batteries.