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羟基氧化镍的结构及电化学性能 总被引:2,自引:0,他引:2
为了研究不同方法合成的NiOOH的结构及电化学性能,以硝酸镍、氢氧化镍为原料,碱性条件下以过二硫酸钾为氧化剂,用均相化学氧化法和固相化学氧化法分别合成了可用于碱性电池正极材料的羟基氧化镍;用扫描电子显微镜法(SEM)、X射线衍射光谱法(XRD)及傅立叶变换红外光谱法(FTIR)等手段,表征了羟基氧化镍的结晶形貌、晶体结构及红外光谱性;用CV方法测定了合成羟基氧化镍的电化学性能,并测试了以羟基氧化镍为正极材料的Zn-Ni电池的放电性能。结果表明:均相化学氧化法和固相化学氧化法合成的羟基氧化镍分别为单纯的b-NiOOH和以b-NiOOH为主的b/g-NiOOH的混合物;合成的b/g-NiOOH的混合物具有较b-NiOOH更良好的电化学可逆性和更高的放电比容量,其初始放电比容量为231mAh·g-1。 相似文献
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以葡萄糖、NH4H2PO4、V2O5和LiF为原料,分别通过液相法和固相法合成了锂离子电池正极材料LiVPO4F/C复合材料,并通过X-射线衍射(XRD)、扫描电镜(SEM)及电化学测试技术对复合材料的结构、形貌及电化学性能进行了表征。结果表明,两种方法所合成复合材料均由三斜结构的LiVPO4F与碳组成;液相法所合成的材料首次放电比容量分别为133.7(0.2 C)、124.9 mAh/g(0.5 C)和118.7 mAh/g(1 C),明显高于相同测试条件下固相法所合成材料的首次放电比容量[131.2(0.2 C)、121.4 mAh/g(0.5 C)和104.9 mAh/g(1 C)],并且液相法合成的复合材料循环性能优于固相法合成的复合材料;液相法合成的LiVPO4F/C复合材料具有良好的循环性能和倍率性能,其2 C和5 C的放电比容量分别高达114 mAh/g和98 mAh/g,循环50次后,容量损失率均小于1%。 相似文献
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碳纳米管是一种新型碳材料,是碳的同素异形体,其合成方法主要有4种:电弧法、激光法、化学气相沉积法、燃烧法.燃烧法可以同时提供碳纳米管生长所必需的热源、碳源、催化剂,具有实验设备简单、常压下即可制备等优点,是目前研究合成碳纳米管的热点技术.综述了该领域国内外的研究状况,详细介绍了各自的实验设备及方法,分析比较了各种方法的优缺点.重点阐述介绍了一种新的合成方法--V型热解火焰法,通过实验证明其是一种较好的碳纳米管制备方法.该方法可以实现碳纳米管的可控制生长,并且能实现工业化生产,是一种极具发展潜力的燃烧合成技术. 相似文献
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Nanocrystalline yttria powders have been successfully synthesized by using yttrium nitrate as starting salt and ammonium hydrogen
carbonate as precipitant. It was found that a small amount of ammonia sulfate in the yttrium nitrate solution can effectively
reduce the agglomeration and the resultant powders display good dispersion. Pure cubic phase yttria powders were prepared
by calcining the precipitate at 1100 °C for 4 h. The size of the as-prepared yttria powders was about 60 nm in diameter and
showed excellent sintering activity. The as-prepared yttria nanopowders and commercial ultrafine alumina powders were used
to fabricate YAG ceramics by solid-state reaction method and transparent YAG ceramics have been obtained by vacuum sintering
at 1760 °C for 6 h. 相似文献
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Mahoney John F. Taylor Scott Perel Julius 《Industry Applications, IEEE Transactions on》1987,(2):197-204
A method for producing ultrafine powders by electrohydrodynamic (EHD) atomization is described. The tip of a consumable electrode (fine wire or rod) is melted by means of electron bombardment. Atomization of the molten wire tip material is accomplished by applying high potentials to the wire feedstock. The expended material is replenished by an automatic wire feed mechanism. The process produces high-quality ultraclean spherical powders, extending the lower range of particle sizes available from conventional atomization methods. This new process avoids many problems associated with EHD atomization employing nozzle and reservoir components. The process provides crucibleless melting, contamination-free powders, and the ability to process high-temperature material (>3000°C). Although currently a laboratory process, this fine powder technology has scaling potential for producing powders of engineering significance. Materials which can be processed by this technology include metals (e.g., Ta, Mo, and metals which are corrosive in the liquid state such as Ti or U), alloys, ceramics, and ceramic-metal combinations. The availability of powder in the form of micrometer and submicrometer spherical particles opens new vistas for material processing applications. The advantages anticipated include controlled microstructures, including rapidly solidified features, amorphous or fine-grained morphologies, material with properties that approach the ideal sinterable powder, and powders with large surface area per unit mass for surface active or dispersive behavior. Potential areas of application include powders for catalysis, injection molding, thick-film pastes, film processing, conductive pastes, and adhesives. 相似文献
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以六水合硫酸镍为电解液,采用超声电解沉积法和三电极系统制备出纳米尺度的镍粉,利用XRD、SEM及EDS分析技术对其进行分析表征,探讨了电沉积过程中阴极电流密度对镍粉粒径大小的影响。实验结果表明,沉积电流密度与阴极过电位成正相关系,阴极过电位越大,所得金属粉体的粒径越小。当电流密度从0.02 A/cm2增加到0.1 A/cm2时,阴极过电位从3.12 V增加到9.83 V,粒径从843 nm减小到38 nm。分析认为,用电解沉积法制备超细金属粉时,采用较大的沉积电流密度可以降低晶核临界形核半径,从而获得较高的形核率;采用超声波可抑制晶核再长大,从而获得粒径较小的镍粉。 相似文献
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ABSTRACTIn this paper, through a new manufacturing process to obtain ultrafine milliseconds detonators, and then test its key performance parameters. An important factor influencing the delay precision detonator is determined by orthogonal experiments, thus optimizing formulations to expect to get a better precision detonator recipe. Through the analysis of the ultrafine particle size testing and the volume delay testing of the drug, the method of improving the accuracy of the delay detonator is put forward, and the technical feasibility experiment is used to verify that the ultrafine drug can improve the precision of the delay detonator in milliseconds. 相似文献
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描述了高纯氧化铟(In2O3)纳米粉末的制备方法及自制的In2O3纳米粉末的物理、化学性能。从BET测试结果和TEM照片看出,该粉末为比表面积大、分散性好的纳米粉末。与进口In2O3粉末进行应用对比表明:新电的电性能以及高温(60℃)贮存后的析气量均差别不大。测试结果显示:该纳米粉末具有良好的缓蚀效果。 相似文献