Rare earth nanostructures based on PrOx/CNT composites as potential electrodes for an asymmetric pseudocapacitor cell

Rare earth metal oxides have been widely used as pseudocapacitor electrodes owing to their unique physical and electronic properties. The present paper reports the synthesis and pseudocapacitor applications of praseodymium oxides, owing to their unique physical properties. PrOx/unzipped carbon-nanotubes were synthesized following a hydrothermal approach. Detailed morphological as well as electrochemical analyses were performed to elucidate how the unique properties of PrOx affect the charge storage ability. Special emphasis was given on the effect of anion intercalation due to the surface oxygen vacancies in PrOx which would contribute towards the pseudocapacitive energy storage. Oxygen intercalation was exploited for the first time in fluorite crystals for fast energy storage and a specific capacitance value as high as 1099 F/g was obtained with the electrodes. An asymmetric supercapacitor prototype was also fabricated with a V2O5/graphene counter electrode and the energy and power density values obtained are as high as 52.08 Wh/kg and 2.9 kW/kg, respectively. (C) 2020 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.