Field-assisted conductive substrate sparks the redox kinetics of Co_(9)S_(8) in Li-and Na-ion batteries  

作　　者：Huanhuan Li Yuxin Chen Huiqin Chen Yantao Wang Jinlong Li Yanping Zheng Linlin Zhang 

机构地区：[1]Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals,Key Laboratory of Green Chemical Media and Reactions,Ministry of Education,School of Chemistry and Chemical Engineering,Henan Normal University,Xinxiang 453007,Henan,China [2]Henan Key Laboratory of Advanced Nylon Materials and Application,School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China [3]Tonghua Normal University,Tonghua 134002,Jilin,China

出　　处：《Journal of Energy Chemistry》2023年第12期114-122,I0005,共10页能源化学（英文版）

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)。

摘　　要：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.

关 键 词：Sulfur defects Mott-Schottky-like heterointerfaces Sodium lon Battery ANODE Full cell 

分 类 号：TM912[电气工程—电力电子与电力传动]