Synthesis of ZnFe2O4@MnO2 Multilevel Nanosheets Structure and Its Electrochemical Properties as Positive Electrodes for Asymmetric Supercapacitors. Issue 17 (7th May 2019)

• Record Type: Journal Article
• Authors: Sun, Shuanggan; Zhang, Xinyang; Wu, Yunpeng; Liu, Xilong; Meng, Yanan; Zhao, Xudong; Liu, Porf. Xiaoyang
• Is Part Of: ChemistrySelect. Volume 4:Issue 17(2019)
• Page Start: 5168
• Page End: 5177
• Publication Date: 2019-05-07
• Subjects: hydrothermal method -- nanosheets -- supercapacitors; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201900346
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: ZnFe2 O4 @MnO2 was synthesized by a facile hydrothermal method. The morphology of ZnFe2 O4 @MnO2 was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM photographs showed that the structure of manganese dioxide was affected by the reaction time. The composition of this compound was investigated by XRD and XPS. Electrochemical tests showed that ZnFe2 O4 @MnO2 had more desirable electrical properties than ZnFe2 O4, and the areal capacitance was 1442 Fg −1 at 2 mA cm −2 . It also showed that ZnFe2 O4 @MnO2 possessed superior stability (90%remained after 3000 cycles). Activated carbon and ZnFe2 O4 @MnO2 were used to form the negative and positive electrodes of an asymmetric supercapacitor, respectively. The asymmetric supercapacitor had an energy density and power density of 49.7 Wh kg −1 and 1918.4 W kg −1, respectively. Abstract : The ZnFe2 O4 @MnO2 core‐shell nanosheets was synthesized by two step hydrothermal method. The MnO2 structure can increase the contact area of ZnFe2 O4 with the ions in the electrolyte, and enhance the electrochemical properties of the electrode material. Furthermore, an asymmetric supercapacitor (ASC) is fabricated using ZnFe2 O4 @MnO2 as the negative electrode and activated carbon as the positive electrode. This asymmetric capacitor possesses a high power density.