Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly ...Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly desirable but still challenging.Herein,the N/P/S-rich carbon nanosheets with ultrathin thickness(2–3 nm)and hierarchical porous structure are successfully prepared via phytic acid-driven interfacial phosphorization strategy using S-bridged covalent triazine framework nanosheets(CTFS)as precursor,which are synthesized through a eutectic molten salt-induced ionothermal polymerization.The carbon electrode with adequate N/P/S active sites is pioneeringly introduced in SCRE,clarifying that the coupling hierarchical porous structure and multi-electroactive sites can effectively enhance the interface interaction between carbon electrodes and redox electrolytes via the ex-situ characterizations and theoretical calculations.Consequently,the resultant N/P/S-rich carbon nanosheet(PCTFSC)enables SCRE in KI-doped H2SO4 electrolyte to achieve state-of-the-art specific capacity(1586 mA·h·g^(-1) at 1 A·g^(-1))with 60%of capacity retention at 16 A·g^(-1) and ultra-high energy density of 816 Wh·kg–1,exceeding the reported aqueous supercapacitors thus far.Moreover,the PCTFS based SCRE also exhibits a low self-discharge rate(holding 50%of open circuit potential after 15 h).This study provides new insights to design and regulate advanced carbon materials from the atom level and nano-morphology toward high performance SCRE.展开更多
基金supported by the National Natural Science Foundation of China(22409170)the Hunan Provincial Natural Scientific Foundation of China(2024JJ7315)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(24B0170)the Scientific Research Projects of Hunan University of Arts and Science(24ZZ01).
文摘Controllable fabrication of multi-electroactive sites and morphology-ordered carbon electrodes with excellent capacity and alleviating self-discharge behavior for aqueous redox-enhanced supercapacitors(SCRE)is highly desirable but still challenging.Herein,the N/P/S-rich carbon nanosheets with ultrathin thickness(2–3 nm)and hierarchical porous structure are successfully prepared via phytic acid-driven interfacial phosphorization strategy using S-bridged covalent triazine framework nanosheets(CTFS)as precursor,which are synthesized through a eutectic molten salt-induced ionothermal polymerization.The carbon electrode with adequate N/P/S active sites is pioneeringly introduced in SCRE,clarifying that the coupling hierarchical porous structure and multi-electroactive sites can effectively enhance the interface interaction between carbon electrodes and redox electrolytes via the ex-situ characterizations and theoretical calculations.Consequently,the resultant N/P/S-rich carbon nanosheet(PCTFSC)enables SCRE in KI-doped H2SO4 electrolyte to achieve state-of-the-art specific capacity(1586 mA·h·g^(-1) at 1 A·g^(-1))with 60%of capacity retention at 16 A·g^(-1) and ultra-high energy density of 816 Wh·kg–1,exceeding the reported aqueous supercapacitors thus far.Moreover,the PCTFS based SCRE also exhibits a low self-discharge rate(holding 50%of open circuit potential after 15 h).This study provides new insights to design and regulate advanced carbon materials from the atom level and nano-morphology toward high performance SCRE.
