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1.
综述了作为锂离子电池炭负极材料的石墨类、非石墨类、纳米材料等方面的研究成果,介绍了上述各种材料的特点。通过对石墨类材料的改性,在炭材料中形成纳米级孔、洞、通道等都可能提高锂的可逆贮量和减少不可逆容量损失,有利于负极比容量的提高,从而有利于进一步提高锂离子电池的比能量。  相似文献   

2.
尹鸽平  周德瑞 《炭素》1999,(4):31-36
介绍了按炭素材料的定向程度和定向方式的结构特征对其进行分类的方法;综述了近年各种炭材料作为锂离子电池负极的较新研究进展,着重分析了石墨、焦碳和不可石墨化碳在放电容量、不可逆容量损失、充放电电位和充放电速率等主要性能上的差异及与他们的结构之间的联系;并简要介绍了各自可能的嵌入机理。  相似文献   

3.
硅基材料作为锂离子电池负极具有容量高、来源广泛以及环境友好等优势,有望替代目前应用广泛的石墨负极成为下一代锂离子电池的主要负极材料。硅和碳复合构成的锂离子电池复合负极,不但解决了充放电过程中硅体积效应大和碳容量低的问题,而且综合了碳循环性好和硅容量高的特点。从材料选择、结构设计以及电极优化方面简要介绍了硅/碳复合材料的最新研究进展,并对硅碳复合负极未来发展方向进行了展望。  相似文献   

4.
石墨添加对中间相炭微球电化学性能的影响   总被引:4,自引:0,他引:4  
赵海  胡成秋 《炭素》2005,(2):30-34
以煤焦油沥青为原料,采用聚合法制备中间相炭微球。研究了不同天然鳞片石墨添加量在相同热处理条件下得到的中间相炭微球作为锂离子电池炭负极材料的电化学性能。研究结果表明,石墨的添加使中间相炭微球内部结构变的复杂,X衍射显示石墨的添加降低了炭微球的石墨化度和晶形尺寸。随石墨添加量的增加,电池的首次充放电容量和效率有所减小,三次循环后充放电效率趋于一致。  相似文献   

5.
研究了人造石墨和天然石墨2种载体对所制备的硅/炭复合负极材料电化性能的影响。结果表明:石墨载体严重影响硅/炭复合材料的首次效率、容量、循环寿命和大电流充放电性能,采用人造石墨载体制备的硅/炭复合负极材料性能明显优于天然石墨。充放电曲线表明,第一个循环由于材料未活化,存在极化,放电电压平台较低;随着循环次数的增加,在活性物质表面形成SEI膜,阻碍锂离子的脱嵌,充放电曲线电压平台差扩大;随着充放电电流密度的加大,极化就越严重,充放电曲线电压平台差就越大。  相似文献   

6.
《炭素》2019,(4)
炭负极材料因其具有较高容量与能量密度、较好的循环性能等优点,成为现今主要的商业化锂离子电池负极材料。本文用三不同的原料焦炭制备成炭负极材料,分别采用X-RD、SEM、BET等手段对其进行表征分析,通过电池检测系统对其充放电性能进行测试和结果比较,探讨三种不同前驱体对其电性能的影响。  相似文献   

7.
综述了锂离子二次电池用炭负极材料:石墨、各种体系炭纤维、石墨化中间相炭微球、焦炭、热解炭的结构与电性能等特点,并通过比较选择出最适宜的炭负极材料。  相似文献   

8.
商业化的锂离子电池石墨负极材料的研究进展   总被引:5,自引:0,他引:5  
综述了锂离子电池石墨负极材料的研究进展,对MCMB、天然石墨与人造石墨、炭纤维为代表的石墨负极材料目前的研究和应用现状进行了详细的论述,并对石墨类炭负极的发展作了展望。  相似文献   

9.
文摘     
<正>锂离子电池负极用纤维状炭材料[刊,中]/楠顶,黄正宏,康飞宇,等//新型炭材料,2015(1):1~11纤维状炭材料有各种尺度和形貌,由于成本和性能缺乏竞争力,制约其在锂离子电池负极材料中的应用。随着纳米技术的发展,一些改性后的新型炭纤维表现出良好的负极材料性能。文章综述了近年各种纤维状炭材料用作锂离子电池负极材料的国内外研究进展。依据纤维状炭材料的结构、性能及其研究思路,分别归纳了石墨纤维、炭纤维及具有各种  相似文献   

10.
讨论了几种PAN基炭纤维和炭纤维布作为二次锂离子电池负极的行为。并研究了充放电电流密度以及炭纤维结构对炭负极容量的影响。  相似文献   

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Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  相似文献   

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Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

15.
Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

16.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

17.
In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

18.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。  相似文献   

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