As a promising candidate electrode material in both Li-and Na-ion batteries(L/SIBs),the application of Co_(9)S_(8) is being hindered by its unsatisfactory electrochemical performance caused by the sluggish ion diffusi...As a promising candidate electrode material in both Li-and Na-ion batteries(L/SIBs),the application of Co_(9)S_(8) is being hindered by its unsatisfactory electrochemical performance caused by the sluggish ion diffusion kinetics and drastic volume expansion.Herein,a hybrid material composed of Co_(9)S_(8-x),N-doped carbon foam that seeded with Co nanoparticles(Co_(9)S_(8-x)@Co-NC) is constructed.Particularly,theoretical and experimental results imply that a built-in electric field at the interface of Co and NC is observed due to the variation of Fermi levels,forming rich Mott-Schottky-like heterointerfaces,which can significantly enhance the charge transfer capability between the active materials of Co_(9)S_(8) and conductive NC skeleton.Moreover,the sulfur defects in Co_(9)S_(8-x)can not only effectively lower the energy barrier of the ion diffusion and charge transfer processes,but also endow the target sample with more storage/adsorption/active sites for Li^(+)/Na^(+) ions,thus improving the rate performance of the Co_(9)S_(8-x)@Co-NC composite.As a result,the Co_(9)S_(8-x)@Co-NC exhibits fast surface-controlled redox kinetics and robust cycling stability.For instance,the Co_(9)S_(8-x)@Co-NC displays impressive Li-storage properties in both half and full cells with a high reversible capacity of 1007.4 mA h g^(-1)at 0.1 A g^(-1)after 100 cycles and superior rate capability up to 5 A g^(-1).Moreover,based on these comprehensive merits,the Co_(9)S_(8-x)@Co-NC composite shows decent electrochemical performance(472.2 and 311.1 mA h g^(-1)at 0.1 and 10 A g^(-1),respectively) as an anode for SIBs.This work presents an effective strategy for the construction of Mott-Schottky-like heterointerfaces in Co_(9)S_(8) based materials and provides specific inspiration for future works designing high-performance electrodes via interfacial engineering.展开更多
基金the financial support of the National Natural Science Foundation of China (51902089)the Educational Department of Jilin Province, China (JJKH20230587KJ)the Science and Technology Department of Jilin Province, China (20220101071JC)。
文摘As a promising candidate electrode material in both Li-and Na-ion batteries(L/SIBs),the application of Co_(9)S_(8) is being hindered by its unsatisfactory electrochemical performance caused by the sluggish ion diffusion kinetics and drastic volume expansion.Herein,a hybrid material composed of Co_(9)S_(8-x),N-doped carbon foam that seeded with Co nanoparticles(Co_(9)S_(8-x)@Co-NC) is constructed.Particularly,theoretical and experimental results imply that a built-in electric field at the interface of Co and NC is observed due to the variation of Fermi levels,forming rich Mott-Schottky-like heterointerfaces,which can significantly enhance the charge transfer capability between the active materials of Co_(9)S_(8) and conductive NC skeleton.Moreover,the sulfur defects in Co_(9)S_(8-x)can not only effectively lower the energy barrier of the ion diffusion and charge transfer processes,but also endow the target sample with more storage/adsorption/active sites for Li^(+)/Na^(+) ions,thus improving the rate performance of the Co_(9)S_(8-x)@Co-NC composite.As a result,the Co_(9)S_(8-x)@Co-NC exhibits fast surface-controlled redox kinetics and robust cycling stability.For instance,the Co_(9)S_(8-x)@Co-NC displays impressive Li-storage properties in both half and full cells with a high reversible capacity of 1007.4 mA h g^(-1)at 0.1 A g^(-1)after 100 cycles and superior rate capability up to 5 A g^(-1).Moreover,based on these comprehensive merits,the Co_(9)S_(8-x)@Co-NC composite shows decent electrochemical performance(472.2 and 311.1 mA h g^(-1)at 0.1 and 10 A g^(-1),respectively) as an anode for SIBs.This work presents an effective strategy for the construction of Mott-Schottky-like heterointerfaces in Co_(9)S_(8) based materials and provides specific inspiration for future works designing high-performance electrodes via interfacial engineering.