Mg-Co-Al-LDH nanoparticles with attractive electrochemical performance for supercapacitor

Abstract

In order to strengthen the utilization of abundant magnesium resources in seawater, magnesium-based LDH nanoparticles (Mg-Co-Al-LDH nanoparticles) with attractive specific capacity and cycling stability were synthesized. The nanoparticles were prepared through coprecipitation of Mg(NO₃)₂, Co(NO₃)₂, and Al(NO₃)₃, and then characterized by SEM, FT-IR, and XRD. The electrochemical performances of Mg-Co-Al-LDH nanoparticles were evaluated and researched by galvanostatic charge-discharge test, cyclic voltammogram (CV), and electrochemical impedance spectroscopy (EIS). The results show that the nanoparticles own smooth surface and hexagonal layered structure, particle size is uniformly distributed between 350 and 450 nm. Electrochemical tests reveal that Mg-Co-Al-LDH nanoparticles display superior cycling stability at large current work conditions in charge-discharge tests, good capacitive performance at high scanning rate in CV tests and indicate a small internal resistance through EIS. The nanoparticles display an initial specific capacitance of 381.3 F g⁻¹ at current density of 1 A g⁻¹, with the value remaining 86.32% after 10,000 cycles. In addition, the prepared electrode performs an energy density of 13.09 Wh/kg and a power density of 149.49 W/kg. Besides, owing to the effective utilization of magnesium resources in seawater, Mg-Co-Al-LDH nanoparticles with attracted electrochemical performance are expected to achieve potential applications in supercapacitor.

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