碳纳米管复合导电剂的应用研究

锂离子电池及其相关技术的发展对容量、充放电倍率特性、循环寿命和加工适用性等提出了更高的要求.目前最常用的负极和正极材料与电解液相容性差,充放电过程中结构变化大易剥落导致电池循环稳定性差.鉴于碳纳米管大的长径比、良好的导电性能、优异的力学性能和化学惰性,很适于用作导电剂提升电池性能.本文主要研究了碳纳米管复合材料用作导电剂,并制作成品锂离子电池检测其性能.主要取得了两项实用成果:(1)获得碳纳米管复合导电剂的制备方法,而且采用简单的机械搅拌就可以将复合导电剂进行有效均匀分散,易于进行规模化应用;(2)用碳纳米管复合材料作导电剂,与目前常用的导电剂导电碳黑相比,锂离子电池循环寿命提高一倍以上.     

硅材料在锂离子电池负极中的应用研究进展

硅材料作为锂离子电池负极材料具有比容量大的优点，是高容量锂离子负极材料的研究热点之一。论文综述了近年来锂离子电池硅负极材料的研究进展。分别对硅和含硅材料作为锂离子电池负极材料的发展过程、充放电特性、储锂机理及影响其储锂的各因素进行了分析和总结，并对其存在的问题进行了分析。探讨了采用不同复合物、不同制备方法和合成硅化物等改性方法来提高其循环性能的可行性。指出纳米硅基复合物将是硅负极材料最有希望的发展方向。     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

Synthesis of Nanorods of Crystalline Co3O4Using Carbon Nanotubes as Templates

ＩｎｔｒｏｄｕｃｔｉｏｎＭａｔｅｒｉａｌｓｂａｓｅｄｏｎｃｏｂａｌｔｏｘｉｄｅｓｈａｖｅａｔｔｒａｃｔｅｄａｇｒｅａｔｉｎｔｅｒｅｓｔｉｎｖｉｅｗｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎｓｉｎｓｃｉｅｎｔｉｆｉｃａｎｄｔｅｃｈｎｏｌｏｇｉｃａｌｆｉｅｌｄｓ .1Ｔｈｅｙｈａｖｅｂｅｅｎｕｓｅｄｆｏｒｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆｓｏｌｉｄ ｓｔａｔｅｓｅｎｓｏｒｓ ,2 ｈｅｔｅｒｏｇｅｎｅｏｕｓｃａｔａｌｙｓｔｓ ,3ｅｌｅｃｔｒｏｃｈｒｏｍｉｃｄｅｖｉｃｅｓ (ＥＣＤｓ) 4ａｎｄａｓｉｎｔｅ…     

碳纳米管和乙炔黑对LiCoO2阴极倍率放电性能的影响

分别以多壁碳纳米管(MWCNTs)和乙炔黑(AB)为导电剂,比较了它们对锂离子电池LiCoO2阴极的倍率放电性能的影响.结果表明:MWCNTs的粉体或水性悬浮物作导电剂时,LiCoO2阴极的倍率放电性能差别较大;MWCNTs结晶度高于AB,但团聚比AB严重,粉体在电极片中局部聚集,水性悬浮物在电极片中均匀分散.AB的粉...     

镍系复合氧化物Li_aNi_(0.78)Co_(0.2)Cd_(0.02)O_2的合成及电化学性能

以LiOH·H2O,含镉球状Ni(OH)2和Co2O3为原料,采用改进固相反应法合成镍系复合氧化物LiaNi0.78Co0.2Cd0.02O2锂离子电池正极材料,并通过ICP＿AES,XRD,SEM,TEM及电化学性能测试对该材料进行表征.实验表明,由Co和Cd部分取代Ni元素的复合正极材料LiaNi0.78Co0.2Cd0.02O2仍具有较完好的层状结构,表面分布均匀,颗粒粒径分布窄,且电化学性能稳定.常温下具有较高的可逆容量和优异的循环稳定性,其可逆容量最高达157.8mAh/g,循环50次后容量仍保持138.3mAh/g左右.     

LiCl-KCl熔盐中纯氧氧化提纯单壁碳纳米管

以LiCl-KCl(wLiCl∶wKCl=55∶45)熔盐为反应介质,对在熔盐中纯氧氧化提纯单壁碳纳米管(SWCNT)进行了研究.发现可以通过控制熔盐温度和氧气流量来控制氧化反应温和地进行.将5gSWCNT粗产品分散在200g熔盐中,在470℃下用300mL?min-1氧气氧化2h可获得3.8%SWCNT收率.采用TEM,SEM,TGA和Raman谱对提纯前后SWCNT的形貌和组成进行了分析,发现提纯后SWCNT产品中无定形碳被有效去除,而SWCNT结构未发现明显变化.     

碳纳米管和石墨在电化学嵌锂过程中的协同效应

锂电子电池;负极材料;碳纳米管和石墨在电化学嵌锂过程中的协同效应     

液相氧化碳纳米管的氧化剂选择

研究了在不同氧化剂作用下,碳纳米管引入含氧官能团的情况,提出了利用Boehm滴定法对碳纳米管表面的羧基进行定量分析的方法。结合X-射线光电子能谱对含氧官能团的分析,进一步探讨了碳纳米管氧化的过程和机理。     

Cu-Ni/La2O3热解C2H2制备碳纳米管的研究

Nano-sized and well-dispersed Cu-Ni/La₂O₃ can be obtained by reduction of LaCu_0.2Ni_0.8O₃ with the structure of perovskite. Using Cu-Ni/La₂O₃ as catalyst and C₂H₂ as carbon source, carbon nanotubes with a high yield and narrow diameter distribution can be obtained in the reaction temperature range of 650～700℃. Outer diameter of carbon nanotubes rangs from 9nm to 14nm. TG, Raman and XPS analysis indicate that carbon nanotubes prepared by Cu-Ni/La₂O₃ are relatively higher in graphitic degree.