酚醛树脂基多孔炭微球的制备及其电化学性能研究
发布时间：2018-08-07 14:22
【摘要】：太阳能和风能是最有前景的替代能源,然而两者的间断性特征阻碍了其大规模应用,因此需要开发新型储能设备。材料是储能设备发展的关键,炭材料被认为是新世纪最具前景的材料尤其是多孔炭材料,其多孔结构及较大的比表面积能够有效提高材料的电化学性能。相对于其他纳米结构,球形材料具有更高的体积能量密度。如何有效的制备成为了球形多孔炭材料发展的关键。针对上述问题,本论文提出了以乳液聚合技术为基础,线性酚醛树脂为碳源、硝酸铜为模板剂的多孔炭球的合成方法。通过SEM、TEM、 XRD、BET等一系列表征手段研究了树脂微球的合成因素对最终炭微球形貌、结构的影响,并通过恒流充放电、循环伏安和交流阻抗测试分析了孔径分布对储锂和电容性能的影响。详细探究了固化温度,固化剂用量,溶剂的种类,有机溶剂和油相的比例以及酚醛树脂浓度等合成参数对酚醛树脂微球形成的影响,并研究成球机理。探索结果表明最优微球合成条件为：固化温度为150℃,酚醛树脂与固化剂质量比为1：0.14,乙醇和丙醇作为有机溶剂,有机溶剂和油相的体积比选择1：2或1：3,酚醛树脂的浓度不能太高或太低。在正丙醇体系中,通过调节硝酸铜模板剂的量制备了具有不同孔径结构的多孔炭球,并分析了多孔炭球形貌、孔结构对储锂性能的影响。结果表明随着硝酸铜用量的增加,微球的结构更加疏松中孔含量越高,其储锂性能和倍率性能也随之提高。铜负载量最多的炭微球(HPCM-4)表现出最优异的储锂性能：电流密度为50mA g-1时,首次可逆容量达585 mA h g-1,循环70次后,容量依然稳定在480mA h g-1,在1A g-1的电流密度下,其容量达200mAh g-1。研究了在乙醇体系中硝酸铜模板剂的加入量和炭化条件对多孔炭球形貌、孔结构及其电容性能的影响。结果表明随着硝酸铜加入量的增多,BET比表面积呈增大的趋势,孔径分布也不同。BET比表面积最高(424m2/g)中孔含量最多并且微孔主要集中在0.8nm左右的HPCM-4表现出最优异的电容性能：O.1A g-1的电流密度下循环600次电容值稳定在148F g-1,比表面积电容值达35F cm-2。在700℃保温2h的炭化条件下得到的多孔炭球展现出最好的电容性能在O.1A g-1的电流密度下循环200次后电容值达159F g-1,比表面积电容值达37F cm-2。
[Abstract]:Solar energy and wind energy are the most promising alternative energy sources, but their intermittent characteristics hinder their large-scale application, so it is necessary to develop new energy storage equipment. Materials are the key to the development of energy storage equipment. Carbon materials are considered as the most promising materials in the new century, especially porous carbon materials. Its porous structure and large specific surface area can effectively improve the electrochemical properties of the materials. Compared with other nanostructures, spherical materials have higher bulk energy density. How to effectively prepare spherical porous carbon materials has become the key to the development. In order to solve the above problems, the synthesis method of porous carbon spheres based on emulsion polymerization technology, linear phenolic resin as carbon source and copper nitrate as template was proposed in this paper. The effects of the synthesis factors of resin microspheres on the morphology and structure of the final carbon microspheres were studied by a series of characterization methods, such as SEM-TEM, XRD- BET, etc. The influence of pore size distribution on the performance of lithium storage and capacitance was analyzed by cyclic voltammetry and AC impedance measurements. The effects of curing temperature, amount of curing agent, kinds of solvents, the ratio of organic solvent to oil phase and the concentration of phenolic resin on the formation of phenolic resin microspheres were studied in detail. The results show that the optimum conditions are as follows: curing temperature is 150 鈩，
本文编号：2170304
[Abstract]:Solar energy and wind energy are the most promising alternative energy sources, but their intermittent characteristics hinder their large-scale application, so it is necessary to develop new energy storage equipment. Materials are the key to the development of energy storage equipment. Carbon materials are considered as the most promising materials in the new century, especially porous carbon materials. Its porous structure and large specific surface area can effectively improve the electrochemical properties of the materials. Compared with other nanostructures, spherical materials have higher bulk energy density. How to effectively prepare spherical porous carbon materials has become the key to the development. In order to solve the above problems, the synthesis method of porous carbon spheres based on emulsion polymerization technology, linear phenolic resin as carbon source and copper nitrate as template was proposed in this paper. The effects of the synthesis factors of resin microspheres on the morphology and structure of the final carbon microspheres were studied by a series of characterization methods, such as SEM-TEM, XRD- BET, etc. The influence of pore size distribution on the performance of lithium storage and capacitance was analyzed by cyclic voltammetry and AC impedance measurements. The effects of curing temperature, amount of curing agent, kinds of solvents, the ratio of organic solvent to oil phase and the concentration of phenolic resin on the formation of phenolic resin microspheres were studied in detail. The results show that the optimum conditions are as follows: curing temperature is 150 鈩，
本文编号：2170304
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