【作者】 王磊；

【导师】 赵娇；

【作者基本信息】 大连海事大学 ， 资源与环境（专业学位）， 2023， 硕士

【摘要】 本文主要针对二维二硫化钼作为钠离子电池阳极材料时循环稳定性差和容量低等问题进行研究,通过调变模板剂和碳前驱体对二硫化钼/碳复合材料的孔结构进行改变,从而制备出二硫化钼/多孔碳和二硫化钼/碳立方体复合材料,两种材料均呈现出优异的电化学性能和良好的循环稳定性。1.二硫化钼/多孔碳复合材料中的多孔孔道结构是采用3D有序PS球作为硬模板碳化后所形成的,碳化之后形成的大孔能够增加材料的比表面积、有效地缓解材料在钠离子电池充放电时所产生的机械应力,并且让二硫化钼纳米片在多孔碳材料表面分散更加均匀。当二硫化钼/多孔碳作为钠离子电池负极材料时,在电流密度为500 mA g^-1下循环100圈后电池容量为438 mAh g^-1,在1000 mA g^-1的大电流密度下循环1000圈后容量保持在319.4 mAh g^-1,明显优于没有模板剂加入的二硫化钼/碳对比材料。2.二硫化钼/碳立方体复合材料采用MOF（ZIF-67）作为前驱体,所制备出的碳立方体能够与二硫化钼之间有较强的作用力,使二硫化钼纳米片更好地负载在碳立方体表面。同时碳立方体的加入能够提高二硫化钼的导电性,并提供稳定的框架结构有效地减缓钠离子电池在充放电时所引起的电极体积变化,从而更好地发挥二硫化钼高的容量性能。通过电化学测试,二硫化钼/碳立方体作为钠离子电池负极材料时有较高的比容量,在电流密度为500 mA g^-1下循环100圈后能够提供447 mAh g^-1的比容量,是比较有潜力的一种钠离子电池阳极材料。更多还原

【Abstract】 This thesis mainly focuses on the obstacles of using two-dimensional molybdenum disulfide as cathode materials in sodium ion batteries（SIBs）,such as low cycling stability and capacity.Mo S₂/porous carbon and Mo S₂/cubic carbon composite materials were prepared by using different hard templates and carbon precursors.Both materials showed excellent electrochemical performance and good cycle stability in SIBs.1.The large pores formed by 3D ordered PS spheres as hard templates can increase the surface area of the material,and the effectively relieve the mechanical stress generated during charging and discharging,with molybdenum disulfide nanosheets be dispersed more evenly on its surface.When Mo S₂/porous carbon is used as anode material in SIBs,the battery showed a capacity of 438 mAh g^-1after 100 cycles at a current density of 500 mA g^-1,and a capacity of 319.4 mAh g^-1after 1000 cycles at 1000 mA g^-1,which is obviously higher than that of Mo S₂/carbon control sample.2.MOF（ZIF-67）is used as the precursor of Mo S₂/carbon composite,and the derived Mo S₂/cubic carbon composite showed cubic morphology with well dispersed Mo S₂nanosheets on its surface.Meanwhile,the ZIF-67 derived carbon can provide a stable cubic frame structure for Mo S₂,improve the conductivity of Mo S₂,as well as effectively tolerant the volume change of Mo S₂during charging and discharging,thereby,exhibiting better performance in SIBs.Mo S₂/cubic carbon composite provides a specific capacity of 447 mAh g^-1after 100 cycles at a current density of 500 mA g^-1,which is a good candidate as SIBs anodes.更多还原