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综述了现代锂离子二次电池负极材料研究的四个重点方向--含锂过渡金属氮化物、锡氧化物、过渡金属氧化物和钒基复合氧化物,并系统地阐述了这四种非碳负极材料的嵌脱机理、性能特点及近期的研究现状. 锂离子二次电池;非碳负极材料;嵌脱机理;金属间化合物 相似文献
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采用锡基复合氧化物作为锂离子二次电池负极材料,并对其进行了合成及电化学测试,电化学测试结果表明,样品(包括SnO和SnO2以及在SnO中添加B,P,Al等元素之后的复合氧化物)的可逆容量可分别达到612mAh/g,598mAh/g和658mAh/g,这充分证明了锡基氧化物用于锂离子二次电池是非常合适的,另外,通过X射线衍射分析和SEM(电子描电镜)对锡基复合氧化物作了分析研究,XRD分析结果表明,在SnO中添加B,P,Al等元素之后所焙烧出的产物完全是玻璃体结构,在SEM表征结果中显示出SnO是粒子状结构,在SnO中添加B,P,Al等元素之后,样品的形貌是不规则的四角形态,粒径分布范围较广,结果表明锡基复合氧化物作为锂离子电池负极材料很有应用前景。 相似文献
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采用锡基复合氧化物作为锂离子二次电池负极材料,并对其进行了合成及电化学测试.电化学测试结果表明,样品(包括SnO和SnO2以及在SnO中添加B、P、Al等元素之后的复合氧化物)的可逆容量可分别达到612mAh/g、598mAh/g和658mAh/g.这充分证明了锡基氧化物用于锂离子二次电池是非常合适的.另外,通过X射线衍射分析和SEM(电子扫描电镜)对锡基复合氧化物作了分析研究.XRD分析结果表明,在SnO中添加B、P、Al等元素之后所焙烧出的产物完全是玻璃体结构.在SEM表征结果中显示出SnO是粒子状结构,在SnO中添加B、P、Al等元素之后,样品的形貌是不规则的四角形态,粒径分布范围较广.结果表明锡基复合氧化物作为锂离子电池负极材料很有应用前景. 相似文献
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综述了近年来金属锡、锡基合金及其氧化物负极材料的研究现状,对目前研究存在的问题进行了分析,认为多重缓冲结构的多组分复合锡基合金和合成纳米复合氧化物是锂离子电池锡基合金和氧化物负极材料的主要研究方向. 相似文献
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运用EIS法研究了锂离子正负极材料扣式电池和全电池的界面电荷传递过程,结合Arrhenius方程分别得到了锂离子电池正、负极材料扣式电池和全电池的界面反应活化能。结果表明,正极扣式电池界面反应活化能与正极材料本身性质密切相关,随正极材料的不同而不同;负极碳材料扣式电池界面反应活化能变化较小,负极扣式电池界面反应活化能大于正极扣式电池。全电池界面反应过程活化能与负极界面反应活化能比较接近,说明负极界面反应过程是整个电池界面反应过程的“控制步骤”。 相似文献
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Rare earth compounds as modifiers used widely in modern friction materials can enhance the interracial binding of constituents of materials and improve the comprehensive properties of materials evidently. However, there are still few reports on application of rare earth in automotive friction materials. In order to study the effect mechanism of rare earths in friction materials, a rare earth compound was selected as additive and the effects of materials doped with or without rare earth on friction and wear properties of materials were studied. The microstructure and worn surface morphology were observed by scanning electron microscopy and the macro performance was discussed. Worn surface element constitution of materials was analyzed by energy dispersive spectroscopy. Effect mechanism of rare earths on friction and wear behaviors of friction materials were discussed. The results show that doping rare earths in friction materials can stabilize friction Coefficient, lower the wear rate of materials and increase the impact strength of materials. The flexibility and fracture resistance of materials is greatly improved. Worn surface of materials doped with rare earth is compact and the surface adhesion is greatly enhanced. 相似文献
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简述了室温磁制冷材料的发展历史和纳米技术,概述了磁制冷材料研究的重点。总结了室温磁制冷工质材料具有优良性能的标准,并且给出了从微观、唯象和纳米方面研究室温磁制冷材料的新思路。介绍了纳米技术在室温磁制冷材料研究中的应用,重点讲述了纳米化对室温磁制冷材料的影响,预测了磁制冷材料的发展趋势。 相似文献
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锰在功能材料中的应用 总被引:1,自引:2,他引:1
介绍了锰在磁性材料中的应用、锰在形状记忆合金中的应用、锰在储氢材料中的应用及其作用机理,展示了锰在功能材料中的重要作用,对进一步挖掘锰的应用潜力有一定意义。 相似文献
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为研制在某些特殊工况条件下用的高强度、高耐磨性的铁基耐磨材料,采用烧结一熔渗一热处理工艺研制出一种由Co—Cr—Mo—Si颗粒增强的铁基粉末冶金耐磨材料。结果表明:Co—Cr—Mo—Si硬颗粒单独存在于基体中,起颗粒强化的作用。未熔渗时,孔洞多,硬颗粒与基体界面清晰可见,结合强度低,材料性能较差。随着熔渗量的增多,材料的孔隙度减小,硬颗粒与基体界面结合强度好,材料性能明显提高。同时,材料的断裂主要通过铜相的撕裂,呈现明显的塑性断裂特征。因此,足够的熔渗量可获得各相界面结合较好的一种高性能铁基材料。 相似文献
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绝缘材料质量的好坏是冶金电炉安全运行的重要因素之一,开发新型绝缘材料是当务之急。介绍了新型耐高温绝缘材料的生产工艺及绝缘性能,应用效果证明其具有推广价值。 相似文献
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《粉末冶金学》2013,56(26):465-510
AbstractPublished information on the fatigue behaviour of sintered materials is reviewed.Porous sintered materials exhibit similar fatigue characteristics to cast and wrought materials, including fatigue limits in ferrous materials. Their endurance ratios are slightly lower than those of similar wrought materials and they may depend on porosity content. In some cases fatigue data for sintered materials show less scatter than those for similar wrought materials. The total porosity content, which is mainly determined by compacting conditions, is the most important factor influencing fatigue behaviour. Endurance limit decreases as the porosity content increases. In the copper- and iron-base materials investigated, fatigue behaviour is influenced only slightly by powder characteristics, sintering temperature, atmosphere, and time, and by post-sintering treatments. Environmental and surface conditions seem to influence the fatigue behaviour in the same manner as pore-free materials. However, notches have a less severe effect than on pore-free materials. Fatigue fracture appears to occur in the same manner as in pore-free materials. Fatigue cracks tend to start at the free surface of the specimen in preference to the internal surfaces of pores, in agreement with theoretical predictions. Sintered low-alloy steels can be heat-treated to give a wide range of fatigue strengths, and they are less notch-sensitive than pore-free steels. The fatigue properties of sintered and pore-free materials are compared and sintered materials are shown to possess fatigue strengths in the same range as cast and wrought materials. 相似文献
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材料研究和发展的瞻望 总被引:6,自引:0,他引:6
徐祖耀 《有色金属材料与工程》1999,20(2):49-50
简介材料研究和应用的原则和趋势。指出,特殊性能水泥、“超级钢”、形状记忆材料、生物材料、高阻尼材料、纳米材料和薄膜材料将是下世纪材料发展的热点 相似文献
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MA Doverspike SB Liu P Ennis T Johnson MS Conradi K Luszczynski RE Norberg 《Canadian Metallurgical Quarterly》1986,33(1):14-21
Construction materials management is generally recognized to be the integrated coordination of materials takeoff, purchasing, expediting, receiving, warehousing and distribution. When these functions are not properly managed, materials shortages, surpluses, and cash flow problems are likely to occur. Costly labor delays result when the required quantity or quality of materials are not available when needed. The attributes of materials management systems are discussed and the essential elements of a successful system identified. Owner‐contractor, engineer‐contractor, and home office‐project site communications appear to be critical to the success of the materials management effort. Preconstruction materials planning and personnel orientation and training are also important. The complex online computer programs that are used to coordinate the materials management effort are costly, but essential, if the desired degree of control is to be exerted to prevent potential shortages, surpluses, and cash flow problems. 相似文献