Three-dimensional nitrogen-doped carbon coated hierarchically porous silicon composite as lithium-ion battery anode
三维氮掺杂碳涂层分层多孔硅复合材料作为锂离子电池负极
出版日期:2021
杂志名称:Journal of Alloys and Compounds
卷号:874
期数:suppl_C
刊号:0925-8388
出版日期:2021
简介:Three-dimensional(3D)Nitrogen-dopedcarboncoatedhierarchicallyporoussilicon(hp-Si@NC)compositewithcocontinuousskeletonsandabundantinterconnectedmacroporeswaspreparedbyasol-gelroute,followedbyamagnesiothermicreductionandapolydopaminepyrolyzation.TheBETspecificsurfaceareaandporevolumeoftheobtainedhp-Si@NCcompositearecalculatedtobearound220.4?m2·g─1and0.247?cm3·g─1,respectively.BothhierarchicallyporousSimonolithandhp-Si@NCcompositepossessgreatelectrochemicalperformances.ThehierarchicallyporousSimonolithexhibitsaninitialdischargeandchargecapacityofabout1943and1621?mAh·g─1,andmaintainsareversiblecapacityofabout125?mAh·g─1inthe100thcycle.Thehp-Si@NCcompositerevealsadischargecapacityofabout1077?mAh·g─1andachargecapacityof723?mAh·g─1inthefirstcycle,andareversiblecapacityofaround700?mAh·g─1remainsafter100cycles.Thecoulombicefficiencyincreasesfrom67.1%inthefirstcycleto97%inthesecondcycleandto99%inthe100thcycle,withagreatrateperformance.AllthesefavorableelectrochemicalcharacterizationsbenefitfromuniqueporestructureandN-dopedcarbonlayer.Thehp-Si@NCcompositeobtainedbyintegratingwithsol-gelprocess,magnesiothermicreductionandpolydopaminepyrolyzationcanbepromisinglyappliedasananodeinLi-ionbatterieswithabrightprospect.