Transition metal selenides are regarded as prospective conversion-reaction anodes for potassium-ion batteries(PIBs)because of their relatively high electrical conductivity,large theoretical specific capacity,abundant ...Transition metal selenides are regarded as prospective conversion-reaction anodes for potassium-ion batteries(PIBs)because of their relatively high electrical conductivity,large theoretical specific capacity,abundant resources and low cost.The challenge of the metal selenides originates from a serious volume change during cycling,which induces serious structural collapse and fast capacity degradation.In the present work,the multi-dimensional carbon nano-architectures confined bimetallic selenides(ZnSe/CoSe_(2)@N-CNTs/rGO)were constructed by a facile MOF-assisted strategy.In such special nanoarchitectures,N-doped CNTs protect the metal selenides centers from serious volume expansion/electrode pulverization,as well as improve the sluggish kinetics.ZnSe/CoSe_(2)@N-CNTs/rGO electrode boosts the lifespan of half PIBs with a large discharge specific capacity of 200 m Ah g^(-1)at 2 A g^(-1)after 3800 cycles.The full PIBs battery with ZnSe/CoSe_(2)@N-CNTs/rGO electrode as anode and Prussian blue as cathode exhibits well electrochemical performance(151 m Ah g^(-1)at 100 m A g^(-1)after 100 cycles).DFT calculation suggests that the CNTs could change the K+adsorption energy and decrease K+diffusion energy barrier,which dramatically enhances K+storage kinetics.This work offers an effective material engineering approach for designing hierarchical“all-in-one”electrodes with high excellent cycling stability for PIBs.展开更多
基金supported by the National Natural Science Foundation of China(21806187,51802357)。
文摘Transition metal selenides are regarded as prospective conversion-reaction anodes for potassium-ion batteries(PIBs)because of their relatively high electrical conductivity,large theoretical specific capacity,abundant resources and low cost.The challenge of the metal selenides originates from a serious volume change during cycling,which induces serious structural collapse and fast capacity degradation.In the present work,the multi-dimensional carbon nano-architectures confined bimetallic selenides(ZnSe/CoSe_(2)@N-CNTs/rGO)were constructed by a facile MOF-assisted strategy.In such special nanoarchitectures,N-doped CNTs protect the metal selenides centers from serious volume expansion/electrode pulverization,as well as improve the sluggish kinetics.ZnSe/CoSe_(2)@N-CNTs/rGO electrode boosts the lifespan of half PIBs with a large discharge specific capacity of 200 m Ah g^(-1)at 2 A g^(-1)after 3800 cycles.The full PIBs battery with ZnSe/CoSe_(2)@N-CNTs/rGO electrode as anode and Prussian blue as cathode exhibits well electrochemical performance(151 m Ah g^(-1)at 100 m A g^(-1)after 100 cycles).DFT calculation suggests that the CNTs could change the K+adsorption energy and decrease K+diffusion energy barrier,which dramatically enhances K+storage kinetics.This work offers an effective material engineering approach for designing hierarchical“all-in-one”electrodes with high excellent cycling stability for PIBs.
