Developing suitable electrode materials capable of tolerating severe structural deformation and overcoming sluggish reaction kinetics resulting from the large radius of potassium ion(K+)insertion is critical for pract...Developing suitable electrode materials capable of tolerating severe structural deformation and overcoming sluggish reaction kinetics resulting from the large radius of potassium ion(K+)insertion is critical for practical applications of potassium-ion batteries(PIBs).Herein,a superior anode material featuring an intriguing hierarchical structure where assembled MoSSe nanosheets are tightly anchored on a highly porous micron-sized carbon sphere and encapsulated within a thin carbon layer(denoted as Cs@MoSSe@C)is reported,which can significantly boost the performance of PIBs.The assembled MoSSe nanosheets with expanded interlayer spacing and rich anion vacancy can facilitate the intercalation/deintercalation of K+and guarantee abundant active sites together with a low K+diffusion barrier.Meanwhile,the thin carbon protective layer and the highly porous carbon sphere matrix can alleviate the volume expansion and enhance the charge transport within the composite.Under these merits,the as-prepared Cs@MoSSe@C anode exhibits a high reversible capacity(431.8 mAh g^(-1) at 0.05 A g^(-1)),good rate capability(161 mAh g^(-1) at 5 A g^(-1)),and superior cyclic performance(70.5%capacity retention after 600 cycles at 1 A g^(-1)),outperforming most existing Mo-based S/Se anodes.The underlying mechanisms and origins of superior performance are elucidated by a set of correlated in-situ/ex-situ characterizations and theoretical calculations.Further,a PIB full cell based on Cs@MoSSe@C anode also exhibits an impressive electrochemical performance.This work provides some insights into developing high-performance PIBs anodes with transition-metal chalcogenides.展开更多
Transition-metal compounds have received extensive attention from researchers due to their high reversible capacity and suitable voltage platform as potassium-ion battery anodes.However,these materials commonly featur...Transition-metal compounds have received extensive attention from researchers due to their high reversible capacity and suitable voltage platform as potassium-ion battery anodes.However,these materials commonly feature a poor conductivity and a large volume expansion,thus leading to underdeveloped rate capability and cyclic stability.Herein,we successfully encapsulated ultrafine CoP and CoSb nanoparticles into rich N-doped carbon nanofibers(NCFs)via electrospinning,carbonization,and phosphorization(antimonidization).The N-doped carbon fiber prevents the aggregation of nanoparticles,buffers the volume expansion of CoP and CoSb during charging and discharging,and improves the conductivity of the composite material.As a result,the CoP/NCF anode exhibits excellent potassium-ion storage performance,including an outstanding reversible capacity of 335mAh g^(-1),a decent capacity retention of 79.3%after 1000 cycles at 1Ag^(-1)and a superior rate capability of 148mAh g^(-1)at 5Ag^(-1),superior to most of the reported transition-metalbased potassium-ion battery anode materials.展开更多
基金supported by the National Natural Science Foundation of China(52072323,52122211,51872098,21975154,and22179078)the “Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University+1 种基金the financial support from the Opening Project of National Joint Engineering Research Center for Abrasion Control and Molding of Metal MaterialsHenan Key Laboratory of High-temperature Structural and Functional Materials,Henan University of Science and Technology(HKDNM2019013)。
文摘Developing suitable electrode materials capable of tolerating severe structural deformation and overcoming sluggish reaction kinetics resulting from the large radius of potassium ion(K+)insertion is critical for practical applications of potassium-ion batteries(PIBs).Herein,a superior anode material featuring an intriguing hierarchical structure where assembled MoSSe nanosheets are tightly anchored on a highly porous micron-sized carbon sphere and encapsulated within a thin carbon layer(denoted as Cs@MoSSe@C)is reported,which can significantly boost the performance of PIBs.The assembled MoSSe nanosheets with expanded interlayer spacing and rich anion vacancy can facilitate the intercalation/deintercalation of K+and guarantee abundant active sites together with a low K+diffusion barrier.Meanwhile,the thin carbon protective layer and the highly porous carbon sphere matrix can alleviate the volume expansion and enhance the charge transport within the composite.Under these merits,the as-prepared Cs@MoSSe@C anode exhibits a high reversible capacity(431.8 mAh g^(-1) at 0.05 A g^(-1)),good rate capability(161 mAh g^(-1) at 5 A g^(-1)),and superior cyclic performance(70.5%capacity retention after 600 cycles at 1 A g^(-1)),outperforming most existing Mo-based S/Se anodes.The underlying mechanisms and origins of superior performance are elucidated by a set of correlated in-situ/ex-situ characterizations and theoretical calculations.Further,a PIB full cell based on Cs@MoSSe@C anode also exhibits an impressive electrochemical performance.This work provides some insights into developing high-performance PIBs anodes with transition-metal chalcogenides.
基金financially supported by the National Natural Science Foundation of China(22075147)the Natural Science Foundation of Jiangsu Province(BK20180086).
文摘Transition-metal compounds have received extensive attention from researchers due to their high reversible capacity and suitable voltage platform as potassium-ion battery anodes.However,these materials commonly feature a poor conductivity and a large volume expansion,thus leading to underdeveloped rate capability and cyclic stability.Herein,we successfully encapsulated ultrafine CoP and CoSb nanoparticles into rich N-doped carbon nanofibers(NCFs)via electrospinning,carbonization,and phosphorization(antimonidization).The N-doped carbon fiber prevents the aggregation of nanoparticles,buffers the volume expansion of CoP and CoSb during charging and discharging,and improves the conductivity of the composite material.As a result,the CoP/NCF anode exhibits excellent potassium-ion storage performance,including an outstanding reversible capacity of 335mAh g^(-1),a decent capacity retention of 79.3%after 1000 cycles at 1Ag^(-1)and a superior rate capability of 148mAh g^(-1)at 5Ag^(-1),superior to most of the reported transition-metalbased potassium-ion battery anode materials.
