Oxygen-modulated metal nitride clusters with moderate binding ability to insoluble Li_(2)S_(x) for reversible polysulfide electrocatalysis  

作　　者：Menghao Cheng Zhenyu Xing Rui Yan Zhenyang Zhao Tian Ma Mi Zhou Xikui Liu Shuang Li Chong Cheng 

机构地区：[1]College of Polymer Science and Engineering,State Key Laboratory of Polymer Materials Engineering,Sichuan University,Chengdu,the People's Republic of China [2]College of Biomass Science and Engineering,Sichuan University,Chengdu,the People's Republic of China

出　　处：《InfoMat》2023年第4期1-13,共13页信息材料（英文）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.52161145402,52173133,51903178);the Science and Technology Project of Sichuan Province(Nos.2022YFH0042,2021YFH0180,and 2021YFH0135);Prof.Cheng and Prof.Li acknowledge the support of the State Key Laboratory of Polymer Materials Engineering(No.sklpme2021-4-02,No.sklpme2022-3-07);Fundamental Research Funds for the Central Universities,the 1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(No.ZYJC21047);the innovation project of Med-X Center for Materials,Sichuan University(No.MCM202102).

摘　　要：Multiphase sulfur redox reactions with advanced homogeneous and heterogeneous electrochemical processes in lithium–sulfur(Li–S)batteries possess sluggish kinetics.The slow kinetics leads to significant capacity decay during charge/discharge processes.Therefore,electrocatalysts with adequate sulfurredox properties are required to accelerate reversible polysulfide conversion in cathodes.In this study,we have fabricated an oxygen-modulated metal nitride cluster(C-MoN_(x)-O)that has a moderate binding ability to the insoluble Li_(2)S_(x)for reversible polysulfide electrocatalysis.A Li–S battery equipped with CMoN_(x)-O electrocatalyst displayed a high discharge capacity of 875 mAh g^(-1)at 0.5 C.The capacity decay rate of each cycle was only 0.10%after 280 cycles,which is much lower than the control groups(C-MoO_(x):0.16%;C-MoN_(x):0.21%).Kinetic studies and theoretical calculations suggest that C-MoN_(x)-O electrocatalyst presents a moderate binding ability to the insoluble Li_(2)S_(2)and Li_(2)S when compared to the C-MoO_(x)and C-MoN_(x)surfaces.Thus,the C-MoN_(x)-O can effectively immobilize and reversibly catalyze the solid–solid conversion of Li_(2)S_(2)–Li_(2)S during charge–discharge cycling,thus promoting reaction kinetics and eliminating the shuttle effect.This study to design oxygen-doped metal nitrides provides innovative structures and reversible solid–solid conversions to overcome the sluggish redox chemistry of polysulfides.

关 键 词：electrocatalysts lithium-sulfur batteries metal nitride reversible polysulfide catalysis shuttle effects Menghao Cheng 

分 类 号：O64[理学—物理化学]