Direct synthesis of tin spheres/nitrogen-doped porous carbon composite by self-formed template method for enhanced lithium storage  

作　　者：Kun Liu Jia-ao Wang Hongfei Zheng Xiaodong Sun Zhimo Yang Jianzong Man Xinyu Wang Juncai Sun 

机构地区：[1]Institute of Materials and Technology,Dalian Maritime University,Dalian 116026,China [2]Department of Chemistry and the Oden Institute for Computational Engineering and Sciences,The University of Texas at Austin,Austin,TX,78712-0165,USA [3]College of Materials,Xiamen University,Xiamen 361005,China

出　　处：《Journal of Materials Science & Technology》2022年第9期88-97,共10页材料科学技术（英文版）

基　　金：supported by the China Postdoctoral Science Foundation(No.2020M670719);the Doctoral Research Startup Fund of Liaoning Province(No.2020-BS-066);the Fundamental Research Funds for the Central Universities(No.3132019328)。

摘　　要：To inhibit the agglomeration of tin-based nanomaterials and simplify the complicated synthesis process,a facile and eco-friendly self-formed template method is reported to synthesize tin submicron spheres dispersed in nitrogen-doped porous carbon(Sn/NPC)by pyrolysis of a mixture of disodium stannous citrate and urea.The vital point of this strategy is the formation of Na_(2)CO_(3)templates during pyrolysis.This self-formed Na_(2)CO_(3)acts as porous templates to support the formation of NPC.The obtained NPC provides good electronic conductivity,ample defects,and more active sites.Serving as anode for Li-ion batteries,the Sn/NPC electrode obtains a stable discharge capacity of 674.1 mAh/g after 150 cycles at 0.1 A/g.Especially,a high discharge capacity of 331.2 mAh/g can be achieved after 1100 cycles at 3 A/g.Additionally,a full cell coupled with LiCoO_(2)as cathode yields a discharge capacity of 524.8 mAh/g after 150 cycles at 0.1 A/g.In-situ XRD is implemented to investigate the alloying/dealloying reaction mechanisms.Density functional theory calculation ulteriorly explicates that NPC heightens intrinsic electronic conductivity,and NPC especially pyrrolic-N and pyridinic-N doping facilitates the Li-adsorption ability.Climbing image nudged elastic band method reveals low Li~+diffusion energy barrier in presence of N atoms,which accounts for the terrific electrochemical properties of Sn/NPC electrode.

关 键 词：Tin submicron spheres Nitrogen-doped porous carbon Self-formed template In-situ XRD Li-ion batteries 

分 类 号：TB332[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]