(FeO)_(2)FeBO_(3) nanoparticles attached on interconnected nitrogen-doped carbon nanosheets serving as sulfur hosts for lithium-sulfur batteries

There are still many challenges including low conductivity of cathodes,shuttle effect of polysulfides,and significant volume change of sulfur during cycling to be solved before practical applications of lithium-sulfur(Li-S)batteries.In this work,(FeO)_(2)FeBO_(3) nanoparticles(NPs)anchored on interconnected nitrogen-doped carbon nanosheets(NcNs)were synthesized,serving as sulfur carriers for Li-S batteries to solve such issues.NcNs have the cross-linked network structure,which possess good electrical conductivity,large specific surface area,and abundant micropores and mesopores,enabling the cathode to be well infiltrated and permeated by the electrolyte,ensuring the rapid electron/ion transfer,and alleviating the volume expansion during the electrochemical reaction.In addition,polar(FeO)_(2)FeBO_(3) can enhance the adsorption of polysulfides,effectively alleviating the polysulfide shuttle effect.Under a current density of 1.0 A·g^(-1),the initial discharging and charging specific capacities of the(FeO)_(2)FeBO_(3)@NCNs-2/S electrode were obtained to be 1113.2 and 1098.3mA·h·g^(-1),respectively.After 1000 cycles,its capacity maintained at 436.8 mA·h·g^(-1),displaying a decay rate of 0.08%per cycle.Therefore,combining NCNs with(FeO)_(2)FeBO_(3) NPs is conducive to the performance improvement of Li-S batteries.