Vanadium-based materials are recognized as promising cathodes for high-energy-density aqueous zincion batteries(AZIBs).However,their inherent low intrinsic conductivities and sluggish reaction kinetics curtail their c...Vanadium-based materials are recognized as promising cathodes for high-energy-density aqueous zincion batteries(AZIBs).However,their inherent low intrinsic conductivities and sluggish reaction kinetics curtail their capacity release.Here,we enhanced the electron and ion transport properties of vanadium-based cathodes through heterojunction engineering,coupled with in situ electrochemical activation,significantly enhancing an unprecedented zinc-ion storage capacity and rapid kinetic performance.A heterostructured V_(2)O_(3)/g-C_(3)N_(4)(V_(2)O_(3)/CN)precursor was synthesized via a calcination process firstly.When employed as a cathode in AZIBs,this precursor undergoes an in situ phase transformation into Zn_(3)(OH)_(2-)V_(2)O_(7)-2H_(2)O/C_(3)N_(4)(ZVOH/CN)during the inaugural charging process,while retaining its heterojunction structure.Both electrochemical assessments and theoretical calculations revealed that ZVOH/CN exhibits superior zinc-ion adsorption and migration capabilities compared to conventional vanadium-based cathodes.The formation of the heterojunction amplifies the material's electronic conductivity and ion diffusion kinetics.As a result,the optimal ZVOH/CN composite electrode showcases a remarkable capacity of 518.5 mAh g^(-1)at 0.5 A g^(-1),superior rate performance of 177.8 mAh g^(-1)at 20 A g^(-1),and impressive cycling stability.This work offers a novel design strategy for vanadium-based composite materials as highperformance AZIB cathodes.展开更多
基金financially supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3026)
文摘Vanadium-based materials are recognized as promising cathodes for high-energy-density aqueous zincion batteries(AZIBs).However,their inherent low intrinsic conductivities and sluggish reaction kinetics curtail their capacity release.Here,we enhanced the electron and ion transport properties of vanadium-based cathodes through heterojunction engineering,coupled with in situ electrochemical activation,significantly enhancing an unprecedented zinc-ion storage capacity and rapid kinetic performance.A heterostructured V_(2)O_(3)/g-C_(3)N_(4)(V_(2)O_(3)/CN)precursor was synthesized via a calcination process firstly.When employed as a cathode in AZIBs,this precursor undergoes an in situ phase transformation into Zn_(3)(OH)_(2-)V_(2)O_(7)-2H_(2)O/C_(3)N_(4)(ZVOH/CN)during the inaugural charging process,while retaining its heterojunction structure.Both electrochemical assessments and theoretical calculations revealed that ZVOH/CN exhibits superior zinc-ion adsorption and migration capabilities compared to conventional vanadium-based cathodes.The formation of the heterojunction amplifies the material's electronic conductivity and ion diffusion kinetics.As a result,the optimal ZVOH/CN composite electrode showcases a remarkable capacity of 518.5 mAh g^(-1)at 0.5 A g^(-1),superior rate performance of 177.8 mAh g^(-1)at 20 A g^(-1),and impressive cycling stability.This work offers a novel design strategy for vanadium-based composite materials as highperformance AZIB cathodes.
