掺杂石墨烯基锂离子电池负极材料的制备与性能研究

发布时间：2018-06-12 06:29

本文选题：锂离子电池 + 掺杂石墨烯　；参考：《长春理工大学》2017年硕士论文

【摘要】：锂离子电池由于具有优越的性能而被广泛应用于各种便携式电子设备,但是随着电动车和大规模储能市场的发展,目前商用锂离子电池的性能已经不能满足市场需求。因此,急需提升现有锂离子电池的性能,而制备石墨烯与金属氧化物复合电极材料是一种可行的方案。本文将掺杂型石墨烯与金属氧化物进行复合,制备高性能锂离子电池负极材料,得到了以下结果:(1)以氮掺杂的多孔石墨烯为基质,通过水热法在其表面生长MnO_2纳米线,我们成功制备了氮掺杂石墨烯/MnO_2纳米线复合材料。该材料作为锂离子电池负极材料时,在50mA/g的电流密度下表现出高达937.6 mAh/g的比容量。值得注意的是其具有优越的倍率性能和循环稳定性。在1000mA/g电流密度下,经过2400圈的循环后,仍然维持312 mAh/g的比容量。(2)以氧化石墨为载体与SnCl_2·2H_2O、磺酸基卟啉(TPPS)进行复合后再经过高温碳化,我们成功制备了氮、硫双掺杂石墨烯/SnO_2纳米球复合材料,其中SnO_2的粒径在10 nm左右。该材料用作锂离子电池负极时,在50mA/g的电流密度下拥有860 mAh/g的比容量。经过100圈的循环后仍然保持有845 mAh/g的比容量,表现出良好的循环稳定性。(3)以氧化石墨为载体与磺酸基锡卟啉(SnTPPS)进行复合,再进行高温碳化,我们成功制备了氮、硫掺杂石墨烯/SnO_2纳米球复合材料。对比物理混合方法制备的氮、硫掺杂石墨烯/SnO_2纳米球复合材料,此方法更加简单,而且复合效果更好,获得的SnO_2粒径更小。该材料用作锂离子电池负极时,在50mA/g的电流密度下拥有高的比容量,约为860 mAh/g。经过100圈的循环后仍然保持有684.6 mAh/g的比容量,表现出良好的循环稳定性。
[Abstract]:Lithium ion batteries are widely used in various portable electronic devices because of their superior performance. However, with the development of electric vehicles and large-scale energy storage market, the performance of commercial lithium ion batteries has not been able to meet the market demand. Therefore, it is urgent to improve the performance of lithium-ion batteries, and the preparation of graphene and metal oxide composite electrode materials is a feasible solution. In this paper, doped graphene and metal oxide were used to prepare high performance anode materials for lithium ion batteries. The following results were obtained: 1) MnO-2 nanowires were grown on the surface of porous graphene doped with nitrogen by hydrothermal method. The nitrogen-doped graphene / MnO _ 2 nanowire composites were successfully prepared. As a cathode material for lithium ion battery, the specific capacity of the material is up to 937.6 mAh/g at the current density of 50mA/g. It is worth noting that it has superior rate performance and cycle stability. At the current density of 1000mA/g, after a cycle of 2400 cycles, the specific capacity of 312 mAh/g was maintained. The particle size of Sn-O _ 2 nanospheres is about 10 nm, and the particle size of Sn-doped graphene / SnO-2 nanospheres is about 10 nm. The material has a specific capacity of 860 mAh/g at the current density of 50mA/g when it is used as a cathode for lithium ion batteries. After the 100th cycle, the specific capacity of 845 mAh/g was maintained, showing good cycle stability. The graphite oxide was used as the carrier to compound with the sulfonic tin porphyrin SnTPPSs, and then carbonized at high temperature. We successfully prepared nitrogen. Sulfur doped graphene / SnO2 nanospheres composites. Compared with the nitrogen and sulfur doped graphene / SnO2 nanospheres prepared by the physical mixing method, the method is simpler, the composite effect is better, and the Sno _ 2 particle size is smaller. When used as a cathode for lithium ion batteries, the material has a high specific capacity at the current density of 50mA/g, which is about 860 mg / g. After 100 cycles, the specific capacity of 684.6 mAh/g is maintained, showing good cycle stability.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM912;TB332

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