Oxygen vacancies enhancing capacitance of MgCo2O4 for high performance asymmetric supercapacitors

Here, we report a facile strategy to synthesize MgCo2O4 with abundant oxygen vacancies (OV-MgCo2O4) using for the electrode materials of asymmetric supercapacitors (ACS). Benefiting from the NaBH4 reduction treatment to offer oxygen vacancies, the specific capacitance of OV-MgCo2O4 was improved to 460 F g(-1) (1 A g(-1)), much higher than untreated MgCo2O4 (340 F g(-1) at 1 A g(-1)). We fabricated OV-MgCo2O4//AC ACS device to investigate the further application of OV-MgCo2O4. This hybrid ACS exhibits excellent specific capacity of 52.5 F g(-1) (0.4 A g(-1)), with a great energy density of 18.7 Wh kg(-1) (320 W kg(-1)). Our work demonstrates the important role of oxygen vacancies in improving the capacity of metal oxides. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A facile strategy was reported to synthesize MgCo2O4 with abundant oxygen vacancies (OV-MgCo2O4), resulting in improved specific capacitance. The ACS device fabricated using OV-MgCo2O4 exhibited excellent specific capacity and energy density, demonstrating the important role of oxygen vacancies in enhancing the capacity of metal oxides.