【作者】 高丽君；

【导师】 邵光杰； 李悦生；

【作者基本信息】 燕山大学 ， 化学工程（专业学位）， 2018， 硕士

【摘要】 近几年,电动设备的高速发展,尤其是新能源汽车的出现,对锂离子电池的能量和功率密度提出了更高的需求,而负极材料是决定锂离子电池性能的因素之一。目前传统商业锂离子电池的负极材料石墨理论容量(372 mAh g^-1)低,倍率性能差,阻碍了锂离子电池性能的提高,因此开发高性能负极材料是推动锂离子电池向电动设备高速发展的关键因素。由于新型碳材料石墨烯具有原子级厚度的二维（2D）结构、超好的物理和化学性质,成为了当前科学领域的研究热点。本文以石墨烯基多孔材料为研究对象,以提高锂离子电池的电化学性能为目的,设计并制备了高性能的石墨烯基多孔负极材料。通过无模板法制备出了氮掺杂多孔碳包覆石墨烯材料（GNC）,其中柠檬酸为碳源,尿素作为氮源。研究结果表明热处理温度为700℃制备的GNC具有好的电化学性能和高的比表面积(743.5 m² g^-1);通过氮掺杂提高了GNC的导电性和电化学活性,从而提高了GNC的倍率性能和循环性能。用硬模板制备出了高比表面积蜂窝状石墨烯基多孔碳（HGPC）负极材料。通过表征发现,九水硝酸铁有利于HGPC形成合适的孔结构,增大了HGPC的比表面积(1523.5 m² g^-1);生成更多的活性位点,有利于锂离子的储存,从而提高了HGPC负极材料的电化学性能。HGPC负极材料在200 mA g^-1电流密度下第一次放电比容量达到3184.8 mAh g^-1;在1000 mA g^-1电流密度下循环250次,比容量仍然保持在724mAh g^-1,库伦效率接近100%。更多还原

【Abstract】 In recent years,with the development of the electric equipments,especially the emergence of new energy vehicles,it requires higher energy density and power density of lithium ion batteries.Besides,anode material is one of the decisive factors for improving the performance of lithium ion batteries.The traditional commercial anode material is graphite with unfortunately low Li intercalation capacity(372mAh g^-1 ideally)and poor rate capability,which hinders the improvement of ion battery electrochemistry performance,so developing anode materials with high performance is the key factor to promote the rapid development of lithium ion batteries to electric equipments.Graphene,a new carbon material,has attracted intensive research interests for energy-related applications due to its atomically thin 2D geometrical structure,prominent intrinsic physical and chemical features.In this paper,the grapheme-based porous materials is used as the research object and the graphene-based multihole anode materials with high performance are designed and prepared to improve the electrochemical properties of lithium ion batteries.Graphene-based nitrogen doped porous carbon（GNC）was prepared by Template-free,in the preparation process,sodium citrate is used as carbon source,urea is used as nitrogen source.The research results show that the GNC has well electrochemical performance and large specific surface area(743.5 m² g^-1)by heat treatment temperature of 700℃;The conductivity and electrochemical activity of GNC were improved by nitrogen doping,which promoted the rate capability and cycle performance of GNC.The honeycomb graphene-based porous carbon anode material was prepared by hard-template.It is found that iron nitrate nonahydrate is beneficial to the formation of suitable pore structure that can provide high specific surface areas and more active sites and is advantageous to the lithium ion storage of HGPC,so as to improve the rate capability and cycle performance of HGPC.An initial discharge specific capacity of3184.8 mAh g^-1 was achieved at a current density of 100 mA g^-1,and after 250 cycles,the reversible specific capacity was 724 mAh g^-1 at a current density of 1000 mA g^-1,meanwhile the coulomb efficiency was close to 100%.更多还原