In sodium-ion hybrid capacitors(SIHCs),the high-capacity metal selenide anodes are severely limited by structural instability and polyselenide dissolution/shuttle during cycling.This study proposes an innovative strat...In sodium-ion hybrid capacitors(SIHCs),the high-capacity metal selenide anodes are severely limited by structural instability and polyselenide dissolution/shuttle during cycling.This study proposes an innovative strategy utilizing high-electronegativity N(χ=3.04)to modulate local electronic domains and stabilize amorphous Mo–Se coordination(N/Mo-Se).Through self-polymerization and tunable selenization,N-doped carbon(NC)nanospheres encapsulating N-stabilized amorphous Mo-Se clusters(N/Mo-Se@NC)are successfully constructed.Theoretical and experimental analyses reveal that N-optimization effectively reconstructs the electronic distribution of Mo–Se coordination via strong covalent Mo–N bonds.This significantly enhances the covalency of Mo-Se clusters and induces localized electronic domains,thereby substantially suppressing polyselenide dissolution/shuttle during cycling.Concurrently,the amorphous N/Mo-Se clusters provide isotropic ion diffusion pathways,and together with the threedimensional(3D)conductive networks of the NC,they jointly optimize charge transfer kinetics.The N/Mo-Se@NC anode exhibits a high reversible capacity of 328.7 mAh g^(-1)after 5000 cycles,even at 10.0 A g^(-1),with a remarkable capacity retention of 110%.The assembled N/Mo-Se@NC//AC SIHCs achieve high energy/power densities(236.1 Wh kg^(-1)/9990 W kg^(-1)),demonstrating superior comprehensive performance compared to most previously reported anodes.This study,through high-electronegativity atom modulation and amorphization engineering,opens new avenues for designing highly stable and high-rate Na^(+) storage materials.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52573299)the Natural Science Foundation of Jiangxi province(Grant Nos.20242BAB25223,20232BCJ23025,20232BCJ25040,and 20232BAB214024)the Special Funding Program for Graduate Student Innovation of Jiangxi Province(No.YC2024-S594)。
文摘In sodium-ion hybrid capacitors(SIHCs),the high-capacity metal selenide anodes are severely limited by structural instability and polyselenide dissolution/shuttle during cycling.This study proposes an innovative strategy utilizing high-electronegativity N(χ=3.04)to modulate local electronic domains and stabilize amorphous Mo–Se coordination(N/Mo-Se).Through self-polymerization and tunable selenization,N-doped carbon(NC)nanospheres encapsulating N-stabilized amorphous Mo-Se clusters(N/Mo-Se@NC)are successfully constructed.Theoretical and experimental analyses reveal that N-optimization effectively reconstructs the electronic distribution of Mo–Se coordination via strong covalent Mo–N bonds.This significantly enhances the covalency of Mo-Se clusters and induces localized electronic domains,thereby substantially suppressing polyselenide dissolution/shuttle during cycling.Concurrently,the amorphous N/Mo-Se clusters provide isotropic ion diffusion pathways,and together with the threedimensional(3D)conductive networks of the NC,they jointly optimize charge transfer kinetics.The N/Mo-Se@NC anode exhibits a high reversible capacity of 328.7 mAh g^(-1)after 5000 cycles,even at 10.0 A g^(-1),with a remarkable capacity retention of 110%.The assembled N/Mo-Se@NC//AC SIHCs achieve high energy/power densities(236.1 Wh kg^(-1)/9990 W kg^(-1)),demonstrating superior comprehensive performance compared to most previously reported anodes.This study,through high-electronegativity atom modulation and amorphization engineering,opens new avenues for designing highly stable and high-rate Na^(+) storage materials.
