Pyrite FeS_(2)exhibits an ultrahigh energy density(1671 W·h·kg^(-1),for the reaction of FeS_(2)+4Li=Fe+2Li_(2)S)in secondary lithium-ion batteries,but its poor cycling stability,huge volume expansion,the shu...Pyrite FeS_(2)exhibits an ultrahigh energy density(1671 W·h·kg^(-1),for the reaction of FeS_(2)+4Li=Fe+2Li_(2)S)in secondary lithium-ion batteries,but its poor cycling stability,huge volume expansion,the shuttle effect of polysulfides,and slow kinetic properties limit its practical application.In this work,we synthesize a composite structure material CoS on FeS_(2)surface(FeSx@CoS,1<x≤2)by using a cobalt-containing MOF to improve its cycle stability.It is found that CoS inhibits the side reactions and adsorbs polysulfides.As a result,the modified FeS_(2)shows a higher discharge capacity of 577 mA·h·g^(-1)(919 W·h·kg^(-1))after 60 cycles than 484 mA·h·g^(-1)(778 W·h·kg^(-1))of bare pyrite FeS_(2).This efficient strategy provides a valuable step toward the realization of high cycling stability FeS_(2)cathode materials for secondary lithium-ion batteries and enriches the basic understanding of the influence of FeS_(2)interfacial stability on its electrochemical performances.展开更多
FeSO_(4) has the characteristics of low cost and theoretical high energy density(799 W·h·kg^(-1) with a two-electron reaction),which can meet the demand for next-generation lithium-ion batteries.Herein,FeSO_...FeSO_(4) has the characteristics of low cost and theoretical high energy density(799 W·h·kg^(-1) with a two-electron reaction),which can meet the demand for next-generation lithium-ion batteries.Herein,FeSO_(4) as a novel highperformance conversion-reaction type cathode is investigated.We use dopamine as a carbon coating source to increase its electronic conductivity.FeSO_(4)@C demonstrates a high reversible specific capacity(512 mA·h·g^(-1))and a superior cycling performance(482 mA·h·g^(-1) after 250 cycles).In addition,we further study its reaction mechanism.The FeSO_(4) is converted to Fe and Li2SO_(4) during lithium ion insertion and the Fe-Li_(2)SO_(4) grain boundaries further store additional lithium ions.Our findings are valuable in exploring other new conversion-type lithium ion battery cathodes.展开更多
基金Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.ZYGX2019Z008)the National Natural Science Foundation of China(Grant No.52072061).
文摘Pyrite FeS_(2)exhibits an ultrahigh energy density(1671 W·h·kg^(-1),for the reaction of FeS_(2)+4Li=Fe+2Li_(2)S)in secondary lithium-ion batteries,but its poor cycling stability,huge volume expansion,the shuttle effect of polysulfides,and slow kinetic properties limit its practical application.In this work,we synthesize a composite structure material CoS on FeS_(2)surface(FeSx@CoS,1<x≤2)by using a cobalt-containing MOF to improve its cycle stability.It is found that CoS inhibits the side reactions and adsorbs polysulfides.As a result,the modified FeS_(2)shows a higher discharge capacity of 577 mA·h·g^(-1)(919 W·h·kg^(-1))after 60 cycles than 484 mA·h·g^(-1)(778 W·h·kg^(-1))of bare pyrite FeS_(2).This efficient strategy provides a valuable step toward the realization of high cycling stability FeS_(2)cathode materials for secondary lithium-ion batteries and enriches the basic understanding of the influence of FeS_(2)interfacial stability on its electrochemical performances.
基金Supported by the Fundamental Research Funds for the Central Universities,China(Grant No.ZYGX2019Z008)the National Natural Science Foundation of China(Grant No.52072061)。
文摘FeSO_(4) has the characteristics of low cost and theoretical high energy density(799 W·h·kg^(-1) with a two-electron reaction),which can meet the demand for next-generation lithium-ion batteries.Herein,FeSO_(4) as a novel highperformance conversion-reaction type cathode is investigated.We use dopamine as a carbon coating source to increase its electronic conductivity.FeSO_(4)@C demonstrates a high reversible specific capacity(512 mA·h·g^(-1))and a superior cycling performance(482 mA·h·g^(-1) after 250 cycles).In addition,we further study its reaction mechanism.The FeSO_(4) is converted to Fe and Li2SO_(4) during lithium ion insertion and the Fe-Li_(2)SO_(4) grain boundaries further store additional lithium ions.Our findings are valuable in exploring other new conversion-type lithium ion battery cathodes.
