Tuning of interactions between cathode and lithium polysulfide in Li-S battery by rational halogenation  

作　　者：Samson O.Olanrele Zan Lian Chaowei Si Shuo Chen Bo Li 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,Liaoning,China [3]Key Laboratory of Functional Inorganic Material Chemistry(Ministry of Education of China),School of Chemistry and Materials Science,Heilongjiang University,Harbin 150080,Heilongjiang,China [4]Chemical Sciences Department,Mountain Top University,Ogun State,Nigeria

出　　处：《Journal of Energy Chemistry》2020年第10期147-152,共6页能源化学（英文版）

基　　金：supported by the NSFC(21573255);the Natural Science Foundation of Liaoning Province(20180510014);supported Joint Research Fund Liaoning Shenyang National Laboratory for Materials Science and the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC);supported by the Special Program for Applied Research on Super Computation of the NSFC Guangdong Joint Fund(the second phase)under Grant no.U1501501。

摘　　要：Li-S batteries have aroused intense interests as one of the most promising high-energy-density storage technology.However,the complex undesired shuttle effect induced by dissolution and diffusion of lithium polysulfide intermediates remains the major setback of this technology.Chemical modification of carbon cathode through heteroatom-doping is widely accepted as an effective method to inhibit the shuttle effect in Li-S battery cathode.Herein,using first principle calculations,we systematically examined the interaction between halogenated graphene and lithium polysulfide species.It is found that the halogen dopants(F,Cl,Br,I)significantly modify the local electronic structure of adsorption site and further induce a polarization to trap the polysulfides.Interestingly,a concave curve is observed from F to I for lithium polysulfide adsorption rather than a linear relation.The exceptions demonstrated from iodine dopant is carefully analyzed and attributed to its unique charge state.Moreover,boron as second dopant further strengthens the interaction between halogenated graphene and polysulfide molecule.Based on halogenation strategy,lithium polysulfide/cathode interactions are tuned in a wide range,which can also be of great importance to accelerate redox reaction in Li-S battery.Overall,an effective method by halogenation is verified to regulate the adsorption of lithium polysulfide and also enhance the reaction kinetics of the Li-S battery system.

关 键 词：Li-S battery HALOGENATION Shuttle effect CO-DOPING 

分 类 号：TM912[电气工程—电力电子与电力传动]