Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To o...Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.展开更多
基金supported by Natural Science Foundation of Ningxia Province,China(No.2023AAC05047)Special Project for the Central-Guided Local Science and Technology Development(No.2024FRD05062)+1 种基金Graduate Student Innovation Project of North Minzu University(No.YCX24102)Ningxia Science and Technology Innovation Team for Key Materials and Devices in High-Performance Secondary Batteries(No.2024CXTD003).
文摘Although manganese-based oxide is regarded as a promising cathode material for zincion hybrid supercapacitors(ZHSCs),its practical application is hindered by slow zinc ion diffusion and the instability of MnO_(2).To overcome this obstacle,a δ-MnO_(2)/MXene heterostructure was created using a simple one-step process under gentle condition.The ZHSC was assembled using this heterostructure as the cathode,activated carbon(AC)as the anode and 2 mol·L−1 ZnSO_(4) as the electrolyte.The resultingδ-MnO_(2)/MXene//ZnSO4//AC ZHSC shows a maximum specific capacitance of 97.4 F·g^(−1) and an energy density of 32.27 Wh·kg^(−1) at the best cathode-to-anode mass ratio.Ex situ characterizations reveal the reversible energy storage mechanism combing Zn^(2+)insertion/extraction in the cathode,ion adsorption and desorption on the anode surface,and partial reversible formation and dissolution of Zn_(4)SO_(4)(OH)_(6)·5H_(2)O(ZHS)components on both electrodes.Adding of Mn^(2+)to the electrolyte reduced Mn dissolution,improving the ZHSC’s specific capacitance and energy density to 140.4 F·g^(−1) and 49.36 Wh·kg^(−1),respectively,while also enhancing its rate performance and cyclability.The improved electrochemical reaction kinetics was verified through various tests.The results suggest that the δ-MnO_(2)/MXene heterostructure has great potential as a high-performance cathode material for ZHSCs.
