Tuning the nucleation and decomposition of Li2O_(2) by fluorine-doped carbon vesicles towards high performance Li-O_(2) batteries  

作　　者：Shiyu Ma Hongchang Yao Zhongjun Li Qingchao Liu 

机构地区：[1]Green Catalysis Center,and College of Chemistry,Zhengzhou University,Zhengzhou 450001,Henan,China

出　　处：《Journal of Energy Chemistry》2022年第7期614-622,I0015,共10页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Grant No.21701145);the China Postdoctoral Science Foundation(Grant Nos.2017M610459,2018T110739)。

摘　　要：Li-O_(2) batteries provide an attractive and potential strategy for energy conversion and storage with high specific energy densities.However,large over-potential in oxygen evolution reactions (OER) caused by the decomposition obstacles of Li_(2)O_(2) seriously impedes its electrochemical performances.Herein,a novel N,O,S and F co-doping vesicular carbon was prepared by self-template pyrolysis method and used in LiO_(2) battery to tune the nucleation and decomposition of Li_(2)O_(2).The introduction of F in the carbon matrix with suitable content can regulate the adsorption of intermediates,through which the morphology of Li_(2)O_(2) can be controlled to film,favorable to its decomposition in charge process.The cathode based on the optimized F doped carbon vesicle exhibits improved electrochemical performances including a low over-potential,large capacity and a long-term stability.Density functional theory (DFT) results show that F and C in C–F bond hasve a strong interaction to Li and O in Li_(2)O_(2),respectively,which can enhance the transfer of electrons from Li_(2)O_(2) to the carbon matrix to generate hole polaron and thus accelerate the delithiation and decomposition of Li_(2)O_(2).This work provides a new sight into understanding the mechanism of nucleation and decomposition of Li_(2)O_(2) for the development of high-performance Li-O_(2) batteries.

关 键 词：Li-O_(2)batteries F-doped carbon vesicles DFT Li2O_(2)nucleation and decomposition 

分 类 号：TQ127.11[化学工程—无机化工] TM911.41[电气工程—电力电子与电力传动]