Modulating eg orbitals through ligand engineering to boost the electrocatalytic activity of NiSe for advanced lithium-sulfur batteries  

作　　者：Tianran Yan Jie Feng Pan Zeng Gang Zhao Lei Wang Cheng Yuan Chen Cheng Youyong Li Liang Zhang 

机构地区：[1]Institute of Functional Nano&Soft Materials(FUNSOM),Soochow University,Suzhou 215123,Jiangsu,China [2]Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University,Suzhou 215123,Jiangsu,China [3]Jiangsu Key Laboratory of Advanced Negative Carbon Technologies,Soochow University,Suzhou 215123,Jiangsu,China

出　　处：《Journal of Energy Chemistry》2022年第11期317-323,I0009,共8页能源化学（英文版）

基　　金：supported by the Natural Science Foundation of Jiangsu Province (BK20190814);the National Natural Science Foundation of China (11905154);the Suzhou Science and Technology Project-Prospective Application Research Program(SYG202109);the Gusu innovative and entrepreneurial talent(ZXL2019245);the Collaborative Innovation Center of Suzhou Nano Science&Technology;the 111 Project;Suzhou Key Laboratory of Functional Nano&Soft Materials,Soochow University-Western University Centre for Synchrotron Radiation Research

摘　　要：Accelerating the sluggish redox kinetics of lithium polysulfides(LiPSs)by electrocatalysis is essential to achieve high performance lithium-sulfur(Li-S)batteries.However,the issue of insufficient catalytic activity remains to be addressed.Herein,a strategy of modulating e_(g) orbitals through ligand engineering has been proposed to boost the catalytic activity of NiSe for rapid LiPSs redox conversion.The X-ray spectroscopic measurements and theoretical calculations reveal that partial substitution of Se with N disrupts the octahedral coordination of Ni atoms in NiSe,leading to the reduced degeneracy and upward shift of e_(g) orbitals of Ni 3 d states.As a consequence,the bonding strength of N-substituted NiSe(N-NiSe)with LiPSs is enhanced,which facilitates the interfacial charge transfer kinetics and accelerates the LiPSs redox kinetics.Therefore,the Li-S batteries assembled with N-NiSe present a high capacity of 682.6 mAh g^(-1) at a high rate of 5 C and a high areal capacity of 6.5 mAh cm^(-2)at a high sulfur loading of 6 mg cm^(-2).This work provides a promising strategy to develop efficient transition-metal based electrocatalysts for Li-S batteries through e_(g) orbital modulation.

关 键 词：Li-S batteries eg orbitals modulation Ligand engineering Shuttle effect Redox kinetics 

分 类 号：TM912[电气工程—电力电子与电力传动] O643.36[理学—物理化学]