Natural Stibnite for Lithium‑/Sodium‑Ion Batteries:Carbon Dots Evoked High Initial Coulombic Efficiency  

作　　者：Yinger Xiang Laiqiang Xu Li Yang Yu Ye Zhaofei Ge Jiae Wu Wentao Deng Guoqiang Zou Hongshuai Hou Xiaobo Ji 

机构地区：[1]College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,People’s Republic of China [2]College of Science,Hunan University of Technology and Business,Changsha 410205,People’s Republic of China [3]School of Material Science and Engineering,Zhengzhou University,Zhengzhou 450001,People’s Republic of China

出　　处：《Nano-Micro Letters》2022年第8期208-228,共21页纳微快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (51904342, 52074359, U21A20284);Hunan Provincial Science and Technology Plan (2020JJ3048);the Science and Technology Innovation Program of Hunan Province (2021RC3014, 2020RC4005, 2019RS1004)

摘　　要：The application of Sb_(2)S_(3)with marvelous theoretical capacity for alkali metal-ion batteries is seriously limited by its poor electrical conductivity and low initial coulombic efficiency(ICE).In this work,natural stibnite modified by carbon dots(Sb_(2)S_(3)@xCDs)is elaborately designed with high ICE.Greatly,chemical processes of local oxidation–partial reduction–deep coupling for stibnite reduction of CDs are clearly demonstrated,confirmed with in situ high-temperature X-ray diffraction.More impressively,the ICE for lithium-ion batteries(LIBs)is enhanced to 85%,through the effect of oxygen-rich carbon matrix on C–S bonds which inhibit the conversion of sulfur to sulfite,well supported by X-ray photoelectron spectroscopy characterization of solid electrolyte interphase layers helped with density functional theory calculations.Not than less,it is found that Sb–O–C bonds existed in the interface effectively promote the electronic conductivity and expedite ion transmission by reducing the bandgap and restraining the slip of the dislocation.As a result,the optimal sample delivers a tremendous reversible capacity of 660 mAh g^(−1)in LIBs at a high current rate of 5 A g^(−1).This work provides a new methodology for enhancing the electrochemical energy storage performance of metal sulfides,especially for improving the ICE.

关 键 词：Carbon dots Sb_(2)S_(3) Initial Coulombic efficiency Interfacial bond ANODE 

分 类 号：TB332[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]