木质素基碳微球的制备及储钠性能研究

发布时间：2018-04-08 09:45

  本文选题：钠离子电池　切入点：负极材料　出处：《天津工业大学》2017年硕士论文

【摘要】：随着电动汽车和混合动力汽车产品在国内的快速普及,锂离子电池作为动力电池的来源需求量快速增长。锂资源的消耗量呈现井喷趋势,然而由于锂资源在地壳储存有限,锂资源终将被耗尽。由于钠的含量丰富,与锂又属于同一主族,其化学性质相似,所以钠离子电池被认为是代替锂离子电池的不二选择。由于钠离子的半径(0.102 nm)大于锂离子半径(0.076 nm),溶剂化的钠离子无法嵌入到石墨层间,所以石墨材料作为负极不再适用于钠离子电池。经过科学家大量的研究,硬碳材料是作为钠离子电池负极材料的首选。本论文采用造纸废料木质素磺酸盐为前驱体,采用简单的喷雾干燥法制备硬碳微球,经过高温1250℃碳化。作为钠离子电池负极材料,研究其储钠性能。为了提高硬碳微球的容量和首次库伦效率,同时复合了酚醛树脂,在调控硬碳微球形貌的同时改变其电化学性能。电化学测试表明,纯的木质素磺酸盐首次可逆比容量达到249 mAh/g,首次库伦效率为59.7%。经过酚醛树脂复合后,复合材料的容量得到明显提高,其中酚醛树脂/木质素质量比为1/9时,首次可逆比容量高达350 mAh/g,首次库伦效率为61.41%;酚醛树脂/木质素质量比为5/5时,首次可逆比容量为321 mAh/g,库伦效率为71.06%。同时,该电极表现出优异的循环稳定性,在100 mA/g的电流密度下循环200次后容量保持率在95%以上。采用富氮材料三聚氰胺做为氮源,用喷雾干燥法制备掺氮木质素硬碳微球,低温700℃碳化,作为钠离子电池负极材料,探究掺氮对储钠性能的影响。经过电化学性能测试发现,700℃碳化后木质素基硬碳微球可逆比容量为122 mAh/g,掺氮后的木质素硬碳微球可逆比容量为207mAh/g,并且具有较好的循环稳定性。
[Abstract]:With the rapid popularity of electric vehicles and hybrid vehicles in China, the demand for lithium ion batteries as a source of power batteries is increasing rapidly.The consumption of lithium resource appears blowout trend. However, because of the limited storage of lithium resource in the crust, lithium resource will eventually be exhausted.Because of the abundance of sodium and the similar chemical properties of lithium and lithium, sodium ion batteries are considered to be the best alternatives for lithium ion batteries.Because the radius of sodium ion is 0.102 nm) and the radius of lithium ion is 0.076 nm, the solvated sodium ion can not be embedded into the graphite layer, so the graphite material is no longer suitable for sodium ion battery as negative electrode.After a lot of research by scientists, hard carbon materials are the first choice of anode materials for sodium ion batteries.In this paper, hard carbon microspheres were prepared by simple spray drying method using lignin sulfonate as precursor, and carbonized at high temperature of 1250 鈩，

本文编号：1721072