AV4+-V2O5 cathode with mixed vanadium valences was prepared via a novel synthetic method using VOOH as the precursor,and its zinc-ion storage performance was evaluated.The products are hollow spheres consisting of nan...AV4+-V2O5 cathode with mixed vanadium valences was prepared via a novel synthetic method using VOOH as the precursor,and its zinc-ion storage performance was evaluated.The products are hollow spheres consisting of nanoflakes.The V4+-V2O5 cathode exhibits a prominent cycling performance,with a specific capacity of 140 mAhg-1 after 1000 cycles at 10 A g.1,and an excellent rate capability.The good electrochemical performance is attributed to the presence of V4+,which leads to higher electrochemical activity,lower polarization,faster ion diffusion,and higher electrical conductivity than V2O5 without V4+.This engineering strategy of valence state manipulation may pave the way for designing high-performance cathodes for elucidating advanced battery chemistry.展开更多
Biphasic and multiphasic compounds have been well clarified to achieve extraordinary electrochemical properties as advanced energy storage materials.Yet the role of phase boundaries in improving the performance is rem...Biphasic and multiphasic compounds have been well clarified to achieve extraordinary electrochemical properties as advanced energy storage materials.Yet the role of phase boundaries in improving the performance is remained to be illustrated.Herein,we reported the biphasic vanadate,that is,Na_(1.2)V_(3)O_(8)/K_(2)V_(6)O_(16)·1.5H_(2)O(designated as Na0.5K0.5VO),and detected the novel interfacial adsorption-insertion mechanism induced by phase boundaries.Firstprinciples calculations indicated that large amount of Zn^(2+)and H^(+)ions would be absorbed by the phase boundaries and most of them would insert into the host structure,which not only promote the specific capacity,but also effectively reduce diffusion energy barrier toward faster reaction kinetics.Driven by this advanced interfacial adsorption-insertion mechanism,the aqueous Zn/Na_(0.5)K_(0.5)VO is able to perform excellent rate capability as well as long-term cycling performance.A stable capacity of 267 mA h g^(-1)after 800 cycles at 5 A g^(-1)can be achieved.The discovery of this mechanism is beneficial to understand the performance enhancement mechanism of biphasic and multiphasic compounds as well as pave pathway for the strategic design of highperformance energy storage materials.展开更多
基金supported by National Natural Science Foundation of China(Nos.51802356,51872334,and 51572299)Innovation-Driven Project of Central South University(No.2018CX004)
文摘AV4+-V2O5 cathode with mixed vanadium valences was prepared via a novel synthetic method using VOOH as the precursor,and its zinc-ion storage performance was evaluated.The products are hollow spheres consisting of nanoflakes.The V4+-V2O5 cathode exhibits a prominent cycling performance,with a specific capacity of 140 mAhg-1 after 1000 cycles at 10 A g.1,and an excellent rate capability.The good electrochemical performance is attributed to the presence of V4+,which leads to higher electrochemical activity,lower polarization,faster ion diffusion,and higher electrical conductivity than V2O5 without V4+.This engineering strategy of valence state manipulation may pave the way for designing high-performance cathodes for elucidating advanced battery chemistry.
基金National Natural Science Foundation of China,Grant/Award Numbers:51932011,51802356,51972346Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,Grant/Award Number:CSUZC202003+1 种基金Innovation-Driven Project of Central South University,Grant/Award Number:2020CX024Program of Youth Talent Support for Hunan Province,Grant/Award Number:2020RC3011。
文摘Biphasic and multiphasic compounds have been well clarified to achieve extraordinary electrochemical properties as advanced energy storage materials.Yet the role of phase boundaries in improving the performance is remained to be illustrated.Herein,we reported the biphasic vanadate,that is,Na_(1.2)V_(3)O_(8)/K_(2)V_(6)O_(16)·1.5H_(2)O(designated as Na0.5K0.5VO),and detected the novel interfacial adsorption-insertion mechanism induced by phase boundaries.Firstprinciples calculations indicated that large amount of Zn^(2+)and H^(+)ions would be absorbed by the phase boundaries and most of them would insert into the host structure,which not only promote the specific capacity,but also effectively reduce diffusion energy barrier toward faster reaction kinetics.Driven by this advanced interfacial adsorption-insertion mechanism,the aqueous Zn/Na_(0.5)K_(0.5)VO is able to perform excellent rate capability as well as long-term cycling performance.A stable capacity of 267 mA h g^(-1)after 800 cycles at 5 A g^(-1)can be achieved.The discovery of this mechanism is beneficial to understand the performance enhancement mechanism of biphasic and multiphasic compounds as well as pave pathway for the strategic design of highperformance energy storage materials.
