Hollow CeO <inf>2</inf> spheres conformally coated with graphitic carbon for high-performance supercapacitor electrodes

Publication Type:
Journal Article
Citation:
Applied Surface Science, 2019, 463 pp. 244 - 252
Issue Date:
2019-01-01
Full metadata record
© 2018 Elsevier B.V. Electrode material is essential for supercapacitors which are an important energy storage device that can deliver high power. Herein, we report the successful synthesis of hollow CeO 2 nanospheres conformally coated with graphitic carbon (H-CeO 2 @GC) via a facile hydrothermal method as a kind of electrode materials of supercapacitors. The as-prepared H-CeO 2 @GC hollow spheres presented a high specific surface area (153 m 2 ∙g −1 ), a well-defined hollow structure (a monodisperse size of ∼260 nm with inner diameter of ∼200 nm and shell thickness of ∼30 nm), and nanocrystals of CeO 2 (∼10 nm) conformally encapsulated in ultra-thin graphitic carbon layers. When applied in supercapacitors, the H-CeO 2 @GC hollow spheres delivered a high specific capacitance of 501 F∙g −1 at a current density of 1 A∙g −1 , a high energy/power density, excellent rate capability and long cycle life owing to its unique architecture. In particular, an energy density of 17.2 Wh∙kg −1 with a power density of 2600 W∙kg −1 was achieved. The supercapacitors retained 85% of the specific capacitance (refer to 1 A∙g −1 ) even at a high current density of 15 A∙g −1 and exhibited excellent cycling stability with 93% of the capacity retention after 5000 cycles at 10 A∙g −1 . This work offers a new approach to developing high-performance supercapacitors using the strategy of combining hollow nanosphere architecture and conductive graphitic carbon nanocoating.
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