共查询到20条相似文献,搜索用时 78 毫秒
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本文从血液相容性、组织相容性、低分子物的渗出、药物缓释等方面出发,对等离子体处理、等离子体聚合、等离子体接枝聚合在医用材料表面改性中的应用作了综合介绍。 相似文献
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锂离子电池纳米正极材料 总被引:4,自引:0,他引:4
综述了锂离子电池纳米正极材料的研究进展,阐述了这种材料用于锂离子电池的优势和存在的问题,把纳米正极材料分为过渡金属嵌锂化合物、金属氧化物和金属硫化物和其它纳米正极材料。归纳了不同纳米正极材料的主要制备方法,探讨了材料的制备方法与其结构、形貌和电化学性能之间的关系,展望了纳米正极材料用于锂离子电池的未来前景。 相似文献
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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。 相似文献
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锂离子电池纳米电极材料研究 总被引:29,自引:1,他引:29
采用XRD,TEM方法对纳米相电极材料的结构,形貌进行表征,并用循环伏安法,恒流充放电法对电极材料的嵌锂电化学行为进行研究。结果表明,由于纳米材料的微结构特性使萁 具有优越的嵌锂特性;1)锂离子嵌入电极材料内部的深度小,过程短,具 较大的比表面,有利于采用较大的电流对该电池进行充放电;2)具有较大的嵌锂空间位置,有利于增加电极的锂嵌容量。 相似文献
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REN Yong-huan WU Bo-rong MU Dao-bin YANG Chun-wei ZHANG Cun-zhong WU Feng 《高等学校化学研究》2013,29(1):116-120
Mass triangle model was applied to lithium ion battery for electrolyte conductivity forecasting. Seven kinds of electrolytes with different proportions of 3 solvents were prepared. The solvent proportions of the seven electrolytes varied so as to make the seven coordinate points distribute in the ternary coordinate system to form a forcasting region by the connection of them. Their conductivities were tested and the conductivity value in the forecasting region was calculated based on the tested value by mass triangle model. Conductivity isolines formed in the region and blank area showing no forecasted value existed simultaneously. Optimized electrolyte with superior conductivity was selected according to conductivity variation trendency combined with the attention paid to the no-value-shown blank area. The conductivity of optimized electrolyte{m[ethyl carbonate(EC)]:m[propylene carbonate(PC)]:m[ethylmethyl carbonate(EMC)]=0.19:0.22:0.59} was 0.745 mS/cm at -40 ℃, increased by a factor of 51.4% compared to 0.492 mS/cm of common electrolyte[m(EC):m(PC):m(EMC)=1:1:1]. The accuracy of mass triangle model was demonstrated from the perspective that the maximum value existed in the blank area. Batteries with this optimized electrolyte exhibited a better performance. 相似文献
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低温等离子体技术在催化剂领域的应用 总被引:3,自引:1,他引:3
低温等离子体技术在化学生产中的用途越来越广泛,它在催化剂领域的应用主要表现在以下几个方面:超细颗粒催化剂合成,催化剂再生,催化剂表面处理,活性组分沉淀到基体以及低温等离子体系统中添加催化剂。经过低温等离子体制备或处理过的催化剂,其催化活性有显著提高。在等离子体反应系统中加入适当的催化剂,可以降低等离子体击穿电压,减少能量消耗,提高反应活性。 相似文献
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Henri Groult Tsuyoshi Nakajima Yoshimi Ohzawa Shinichi Komaba 《Journal of fluorine chemistry》2005,126(7):1111-1116
Surface modification of graphite powder has been performed by chemical fluorination using elemental fluorine at 200 °C and 300 °C. This process leads to an increase of the BET surface area due to partial CC bond breaking. Surface analyses performed by secondary ions mass spectrometry have shown that the H + O content at the surface of graphite is significantly decreased by this fluorination treatment. Fluorinated graphite powders have been tested as negative electrodes in Li-ion battery, chronopotentiometry measurements have shown that the fluorinated graphite exhibits better electrochemical performances than raw graphite powder notably due to an increase of the surface area which allows the storage of a higher amount of lithium into the host lattice. In addition, impedance measurements performed in a delithiated state have shown a significant decrease of the total cell resistance, i.e. a decrease of both the charge transfer resistance and the resistance related to the solid electrolyte interface (SEI) layer. 相似文献
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The pressing demand for high-energy/power lithium-ion batteries requires the deployment of cathode materials with higher capacity and output voltage.Despite more than ten years of research,high-voltage cathode mate-rials,such as high-voltage layered oxides,spinel LiNi0.5Mn1.5O4,and high-voltage polyanionic compounds still cannot be commercially viable due to the instabilities of standard electrolytes,cathode materials,and cathode electrolyte interphases under high-voltage operation.This paper summarizes the recent advances in addressing the surface and interface issues haunting the application of high-voltage cathode materials.The understanding of the limitations and advantages of different modification protocols will direct the future endeavours on advancing high-energy/power lithium-ion batteries. 相似文献
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低温等离子体处理聚酯(PET)表面润湿性与表面结构的研究 总被引:11,自引:0,他引:11
陈杰瑢 《高等学校化学学报》1997,18(3):466-471
研究了O2、N2、He、Ar、H2和CH4气体低温等离子体改性聚酯(PET)的表面润湿性与表面结构的关系.用已知表面张力的液体测定接触角,作Zisman曲线,求得试样的临界表面张力γc;并按扩展的Fowkes式计算试样的表面张力γs及其三组分值γsa(色散力)、γsc(偶极矩力)和γ(氢键力),发现经O2、N2、He和Ar等离子体短时间处理的聚酯表面自由能显著增大,表面润湿性增强,主要是聚酯表面张力的氢键力成分的贡献,X射线光电子能谱分析表明,这是由于聚酯表面含氧或含氮极性基团增加所致. 相似文献
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随着新能源如电动汽车、储能电站的蓬勃发展,人们对下一代高性能锂离子电池的能量密度、功率密度和循环寿命提出了更高的要求. 而富锂锰基正极材料xLi2MnO3·(1-x)LiMO2(0 < x < 1,M = Mn、Co、Ni…)具有可逆比容量高(240 ~ 280 mAh·g-1,2.0 ~ 4.8 V)、电化学性能较佳、成本较低等优点,已吸引了研究者的关注,有望成为下一代锂离子电池用正极材料. 本实验室采用固相法和溶胶-凝胶法制备不同的富锂锰基正极材料,其中,溶胶-凝胶法制得的Li[Li0.2Mn0.54Ni0.13Co0.13]O2电极首周期放电比容量277.3 mAh·g-1,50周期循环后容量272.8 mAh·g-1,容量保持率98.4%. 本文重点结合本实验室的研究工作,对新型富锂锰基正极材料xLi2MnO3·(1-x)LiMO2的结构、合成、电化学性能改性和充放电机理等进行总结与评述. 相似文献
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将自行设计和搭建的低温等离子体装置作为离子源,成功地与常压高分辨质谱结合,并将其用于类固醇样品的定性分析.与常规电喷雾质谱相比,用低温等离子体质谱检测类固醇样品具有样品前处理简单、谱图干扰少等优点.对类固醇样品进行了一级质谱以及串联质谱的表征,发现其一级谱图能够体现出类固醇化合物的结构稳定性,而在串联质谱图中则出现了较多的丢水碎片.本工作结合能量计算详细比较分析了典型类固醇样品在碰撞诱导解离(CID)碎裂过程中的丢水过程.另外,通过比较二级质谱的不同以及对其碎裂过程的分析推测,睾酮和去氢表雄酮这对同分异构体得以区分. 相似文献