One-step synthesis of Co(OH)2/SnOx/C hybrid nanosheets for asymmetric solid-state supercapacitors

Material defects play an important role in metal oxide-based or hydroxide-based supercapacitors. Oxygen vacancies as anion vacancy defects can not only offer a high electron conductivity by act as shallow donors but also can adjust the materials' surface properties. Herein, we synthesis a novel oxygen-vacancy-rich Co (OH)(2)/SnO./C hybrid nanosheets which are prepared by using a facile one-step hydrothermal route. Possessing special petal-like nanosheets and rich oxygen vacancies, the as-prepared dual ligand hybrid nanosheets (marked Co(OH)(2)/SnO./C) present a high specific capacitance of 806.36 F g(-1) at 1 A g(-1), much higher than single ligand compound (338.36 F g(-1) or 450.00 F g(-1)). The solid-state asymmetrical super-capacitors assembled with Co(OH)(2)/SnO./ C show energy density of 49.73 Wh kg(-1) with a power density of 1599.98 W kg(-1), and good cycle stability with 64.43% capacitance retention after 20,000 cycles at the current density of 1 A g(-1). (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Material defects, specifically oxygen vacancies, play a crucial role in high electron conductivity and surface property adjustment in metal oxide-based supercapacitors. The novel Co(OH)(2)/SnO./C hybrid nanosheets synthesized in this study exhibit high specific capacitance and good cycle stability, showing potential for use in energy storage applications.