Benefitting from its unique NASICON-type framework,the Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes have aroused extensive interest and have been deemed as the promising cathode candidate for sodium-ion batteries(SIBs).Unfort...Benefitting from its unique NASICON-type framework,the Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes have aroused extensive interest and have been deemed as the promising cathode candidate for sodium-ion batteries(SIBs).Unfortunately,the poor electronic conductivity,combined with the undesirable volume variations,seriously hinders the practical application of NVP cathode,especially at low temperatures.Herein,a dual-strategy,F substitution accompanied by V vacancies and the construction of three-dimensional(3D)nitrogen-doped carbonaceous frameworks(NC),were employed for the NVP cathode(F-NVP/C@3DNC).The former can remarkably decrease the particle size and enhance Na^(+)migration capability,increasing the ionic conductivity.Meanwhile,the electronic connection and effective buffering can be obtained from the latter,strengthening the electrode integrity.Consequently,up to 100 cycles at 0.1 A g^(-1),a reversible capacity of 113.8 mAh g^(-1),approaching the theoretical value(117 mAh g^(-1)),is demonstrated,accompa-nied by impressive capacity retentions at 1.0(93.75%after 4800 cycles)and 20.0 A g^(-1)(92.7%after 1000 cycles).More importantly,even at-20℃,a superior specific capacity(102.6 mAh g^(-1) after 100 cycles at 0.1 A g^(-1))and high capacity retention(86.6%at 20.0 A g^(-1) up to 1000 cycles)can still be obtained simul-taneously.Significantly,the design of F-NVP/C@3DNC provides insights for the fabrication of polyanion cathodes for applications at low temperatures with modified structure stability and reaction kinetics.展开更多
基金support from the faculty startup funds from the Yangzhou University,the Natural Science Foundation of Jiangsu Province (Grant No.BK20210821)the National Natural Science Foundation of China (Grant No.21978251)the Lvyangjinfeng Talent Program of Yangzhou.
文摘Benefitting from its unique NASICON-type framework,the Na_(3)V_(2)(PO_(4))_(3)(NVP)cathodes have aroused extensive interest and have been deemed as the promising cathode candidate for sodium-ion batteries(SIBs).Unfortunately,the poor electronic conductivity,combined with the undesirable volume variations,seriously hinders the practical application of NVP cathode,especially at low temperatures.Herein,a dual-strategy,F substitution accompanied by V vacancies and the construction of three-dimensional(3D)nitrogen-doped carbonaceous frameworks(NC),were employed for the NVP cathode(F-NVP/C@3DNC).The former can remarkably decrease the particle size and enhance Na^(+)migration capability,increasing the ionic conductivity.Meanwhile,the electronic connection and effective buffering can be obtained from the latter,strengthening the electrode integrity.Consequently,up to 100 cycles at 0.1 A g^(-1),a reversible capacity of 113.8 mAh g^(-1),approaching the theoretical value(117 mAh g^(-1)),is demonstrated,accompa-nied by impressive capacity retentions at 1.0(93.75%after 4800 cycles)and 20.0 A g^(-1)(92.7%after 1000 cycles).More importantly,even at-20℃,a superior specific capacity(102.6 mAh g^(-1) after 100 cycles at 0.1 A g^(-1))and high capacity retention(86.6%at 20.0 A g^(-1) up to 1000 cycles)can still be obtained simul-taneously.Significantly,the design of F-NVP/C@3DNC provides insights for the fabrication of polyanion cathodes for applications at low temperatures with modified structure stability and reaction kinetics.
