聚苯乙烯模板法制备锂离子电池材料及电化学性能研究
发布时间：2019-04-03 21:54
【摘要】： 电极材料是制约锂离子电池迅速发展的一个关键因素。材料的性能与合成方法有极大关系,采用传统高温固相法能耗大、周期长,所合成材料晶粒和颗粒的可调控性差,团聚现象比较严重,导致性能较差且不稳定。在本论文中,我们利用聚苯乙烯(PS)模板的空间限域和调控作用,成功地制备了一系列电化学储能材料。研究结果表明,聚苯乙烯既能调控材料的粒径、形貌和结构,又能优化材料的物理化学性质。论文主要内容包括以下几个方面: 一、采用聚苯乙烯模板法制备了有序的大孔LiMn_2O_4。不同煅烧温度影响电极材料的结构、形貌及电化学性能。结果表明,700 oC制备的样品为多孔状,XRD谱图证明制备产物为尖晶石结构。组装成Li/LiMn_2O_4扣式电池,在3.0-4.3V区间以1C的电流充放电,首次放电比容量为113.8 mAh/g,100次循环后仍保持初始容量的86.6%,显示了较好的循环性能。另外,该材料以2 C倍率放电时,容量仍保持90 mAh/g,具有大功率放电特性,且循环性能稳定。利用循环伏安方法研究了大孔LiMn_2O_4的电化学性能和动力学性质,计算了Li+的扩散系数。 二、采用聚苯乙烯模板法制备了高压电极材料LiNi0.5Mn1.5O4,我们成功合成了孔状和亚微米LiNi_(0.5)Mn_(1.5)O_4。通过热分析(DTA、TGA)确定了合成条件,粉末X射线衍射(XRD)表征了产物的晶体结构,用扫描电镜(SEM)观察产物的形貌,通过循环伏安(CV)、电池充放电等测试手段详细考察了不同条件下制备产物的电化学性能。比较得出较佳的煅烧温度为900 oC,在此条件下制备的LiNi_(0.5)Mn_(1.5)O_4在3.5-5.0 V电压区间以0.5 C充放电,首次放电容量为102 mAh/g,186次循环后的容量达到90.1 mAh/g,为初始容量的88.3%,表现出优良的循环性能。 三、采用聚苯乙烯(PS)模板法合成了LiCoO_2、LiFePO_4、Co_3O_4和NiO四种电极材料。通过控制合成温度,烧结时间,升温速度以及聚合物模板的粒径,所制备得到的电极材料形貌新颖,颗粒小,结晶完美。采用粉末X射线衍射(XRD)表征了各种产物的晶体结构,用扫描电镜(SEM)观察产物的形貌,通过循环伏安(CV)和电池充放电等测试手段初步考察了LiCoO_2、LiFePO_4、Co_3O_4和NiO的电化学性能。
[Abstract]:Electrode material is a key factor restricting the rapid development of Li-ion batteries. The properties of the materials have a great relationship with the synthesis method. The traditional high temperature solid phase method has the advantages of large energy consumption, long period, poor controllability of grains and particles, and serious agglomeration, which leads to poor and unstable properties of the synthesized materials. In this thesis, we have successfully prepared a series of electrochemical energy storage materials by using the space limit and regulation of polystyrene (PS) template. The results show that polystyrene can not only control the particle size, morphology and structure of the material, but also optimize the physical and chemical properties of the material. The main contents of this paper are as follows: 1. Ordered macroporous limn _ 2O _ 4 was prepared by polystyrene template method. Different calcination temperatures affect the structure, morphology and electrochemical properties of electrode materials. The results showed that the samples prepared at 700 oC were porous, and the XRD spectra showed that the prepared products were spinel structure. The Li/LiMn_2O_4 button battery was assembled and charged and discharged at a current of 1C in the 3.0 ~ 4.3V range. The initial discharge specific capacity remained 86.6% of the initial capacity after 113.8 mAh/g,100 cycles. It shows better cycle performance. In addition, when the material is discharged at 2 C rate, the capacity of the material is still 90 mAh/g, with high power discharge characteristics, and the cycle performance is stable. The electrochemical and kinetic properties of macroporous limn _ 2O_4 were studied by cyclic voltammetry, and the diffusion coefficients of Li were calculated. Secondly, porous and sub-micron LiNi_ (0.5) Mn_ (1.5) O _ (4) were successfully synthesized by using polystyrene template method to prepare high-pressure electrode material LiNi0.5Mn1.5O4,. The synthesis conditions were determined by thermal analysis (DTA,TGA), the crystal structure of the product was characterized by powder X-ray diffraction (XRD), the morphology of the product was observed by scanning electron microscopy (SEM), and the cyclic voltammetry (CV), was used to observe the morphology of the product. The electrochemical properties of the products prepared under different conditions were investigated in detail by charge-discharge test. The better calcination temperature is 900 oC,. The LiNi_ (0.5) Mn_ (1.5) O _ (3) O _ (4) prepared under this condition is charged and discharged at 0.5 C and the first discharge capacity is 102 mAh/g, in the voltage range of 3.5 脳 5.0 V. After 90.1 mAh/g, cycles, the capacity is 88.3% of the initial capacity, showing excellent cycle performance. Thirdly, four kinds of electrode materials, LiCoO_2,LiFePO_4,Co_3O_4 and nio, were synthesized by polystyrene (PS) template method. By controlling the synthesis temperature, sintering time, heating rate and the particle size of the polymer template, the prepared electrode material has the advantages of novel morphology, small particle size and perfect crystallization. The crystal structures of the products were characterized by powder X-ray diffraction (XRD). The morphology of the products was observed by scanning electron microscopy (SEM). The LiCoO_2,LiFePO_4, was preliminarily investigated by cyclic voltammetry (CV) and battery charging and discharging. Electrochemical properties of Co_3O_4 and NiO.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TM912
本文编号：2453613
[Abstract]:Electrode material is a key factor restricting the rapid development of Li-ion batteries. The properties of the materials have a great relationship with the synthesis method. The traditional high temperature solid phase method has the advantages of large energy consumption, long period, poor controllability of grains and particles, and serious agglomeration, which leads to poor and unstable properties of the synthesized materials. In this thesis, we have successfully prepared a series of electrochemical energy storage materials by using the space limit and regulation of polystyrene (PS) template. The results show that polystyrene can not only control the particle size, morphology and structure of the material, but also optimize the physical and chemical properties of the material. The main contents of this paper are as follows: 1. Ordered macroporous limn _ 2O _ 4 was prepared by polystyrene template method. Different calcination temperatures affect the structure, morphology and electrochemical properties of electrode materials. The results showed that the samples prepared at 700 oC were porous, and the XRD spectra showed that the prepared products were spinel structure. The Li/LiMn_2O_4 button battery was assembled and charged and discharged at a current of 1C in the 3.0 ~ 4.3V range. The initial discharge specific capacity remained 86.6% of the initial capacity after 113.8 mAh/g,100 cycles. It shows better cycle performance. In addition, when the material is discharged at 2 C rate, the capacity of the material is still 90 mAh/g, with high power discharge characteristics, and the cycle performance is stable. The electrochemical and kinetic properties of macroporous limn _ 2O_4 were studied by cyclic voltammetry, and the diffusion coefficients of Li were calculated. Secondly, porous and sub-micron LiNi_ (0.5) Mn_ (1.5) O _ (4) were successfully synthesized by using polystyrene template method to prepare high-pressure electrode material LiNi0.5Mn1.5O4,. The synthesis conditions were determined by thermal analysis (DTA,TGA), the crystal structure of the product was characterized by powder X-ray diffraction (XRD), the morphology of the product was observed by scanning electron microscopy (SEM), and the cyclic voltammetry (CV), was used to observe the morphology of the product. The electrochemical properties of the products prepared under different conditions were investigated in detail by charge-discharge test. The better calcination temperature is 900 oC,. The LiNi_ (0.5) Mn_ (1.5) O _ (3) O _ (4) prepared under this condition is charged and discharged at 0.5 C and the first discharge capacity is 102 mAh/g, in the voltage range of 3.5 脳 5.0 V. After 90.1 mAh/g, cycles, the capacity is 88.3% of the initial capacity, showing excellent cycle performance. Thirdly, four kinds of electrode materials, LiCoO_2,LiFePO_4,Co_3O_4 and nio, were synthesized by polystyrene (PS) template method. By controlling the synthesis temperature, sintering time, heating rate and the particle size of the polymer template, the prepared electrode material has the advantages of novel morphology, small particle size and perfect crystallization. The crystal structures of the products were characterized by powder X-ray diffraction (XRD). The morphology of the products was observed by scanning electron microscopy (SEM). The LiCoO_2,LiFePO_4, was preliminarily investigated by cyclic voltammetry (CV) and battery charging and discharging. Electrochemical properties of Co_3O_4 and NiO.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TM912
【参考文献】
相关期刊论文 前6条
1 王为,郭鹤桐,高建平,于九皋;单分散聚苯乙烯微球的制备[J];材料研究学报;1998年06期
2 邱广明,孙宗华;分散聚合法合成磁性高分子微球[J];功能高分子学报;1993年02期
3 邬泉周;李玉光;;三维有序大孔材料应用研究进展[J];化工进展;2008年03期
4 邢雪坤;吏美伦;陈民勤;吴浩青;;锂在嵌入物Li_xTio_2中的扩散行为[J];化学学报;1982年11期
5 何涛,吴浩青;四元尖晶石相Li-M-Mn-O(M=Ni,Cr,Mo,V)嵌入电极的研究[J];化学学报;1999年07期
6 叶乃清,刘长久,沈上越;锂离子电池正极材料LiNiO_2存在的问题与解决办法[J];无机材料学报;2004年06期
相关博士学位论文 前2条
1 徐化云;锂离子电池正极材料的制备改性及表征[D];中国科学技术大学;2007年
2 杨书廷;锂离子电池正极材料的合成及性能研究[D];大连理工大学;2007年
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