59 research outputs found
Effect of ZnF2 Coating on Performance of LiNi0.5Mn1.5O4 Cathode Material for Lithium-ion Batteries
采用溶胶-凝胶法制备了LiNi0.5Mn1.5O4正极材料,并利用Zn F2对其表面进行包覆改性。XRD、SEM和TEM测试表明,包覆处理不影响材料的晶体结构,2%(质量分数,以LiNi0.5Mn1.5O4质量计,下同)的Zn F2在LiNi0.5Mn1.5O4表面形成了约7 nm厚均匀包覆层。对未包覆的LiNi0.5Mn1.5O4和1%、2%、3%的Zn F2包覆后的LiNi0.5Mn1.5O4的电化学性能进行了考察,发现Zn F2包覆能够减弱电解液与LiNi0.5Mn1.5O4正极材料之间的相互作用,稳定电极表面,提高材料的电化学性能。其中,2%Zn F2包覆样品表现出最佳的循环性能和倍率性能,0.2C电流倍率下循环200圈后,其放电比容量维持在109.0 m A·h/g,保持率为79.7%;5 C电流倍率下循环500圈后,放电比容量维持在94.2 m A·h/g,保持率为85.6%
Preparation and Application of Carboxyl Fluorescence-encoded Microbeads
液相芯片技术又称流式微珠阵列技术,是将溶液中待测物质通过生物分子之间特异性亲和反应结合在类似于细胞大小的经荧光编码的微球体上,利用流式细胞术对同一个微量样本中的多种待测分子同时进行快速定性、定量分析的新一代分子诊断技术平台。检测时,微球颗粒被微量液体传送系统排成单列通过两束激光:一束测定微球自身的颜色从而对被测物进行定性分析,另一束测定微球上报告分子所携带的荧光标记强度从而对被测物进行定量分析。液相芯片是一种非常灵活的多元分析平台,在核酸、蛋白质等生物大分子的大规模分析中具有巨大的应用潜力。 液相芯片技术的载体是表面功能化的荧光编码微球,微球的合成材料有很多,如二氧化硅、聚丙烯酸酯、聚乙烯基...Suspension array, also named as microsphere-based array, is a new clinical diagnostic platform which uses different fluorescence-encoded microbeads coupled with biological probes to capture the analytes for quanlitative and quantitative analysis simultaneously in a micro sample with flow cytometry. Through the fluid system, microbeads pass through the laser detection volume one by one for the anal...学位:理学硕士院系专业:化学化工学院化学系_分析化学学号:2052007115101
Nitrile-Modified 2,5-Di-tert-butyl-hydroquinones as Redox Shuttle Overcharge Additives for Lithium-Ion Batteries
Nitrile-modifled 2,5-di-tert-butyl-hydroquinones were synthesized and investigated as redox shuttle overcharge additives for LiFePO4/Li cells. The cyanoethylation reaction was utilized to synthesize the target molecules 2,5-di-tert-butyl-l,4-di(β-cyanoet
Determination of Melamine in Candies by Triple Quadurupole Liquid Chromatography-Tandem Mass Spectrometry
本文建立了高效液相色谱串联质谱检测糖果中三聚氰胺的方法。以糖果为基质,采用三氯乙酸水溶液超声提取目标分析物,提取液经过离心、净化处理后,用强阳离子交换与反相C18混合填料色谱柱分离,乙腈和l0MMOl/l乙酸铵作为流动相(1:1),用串联质谱在多级反应监测模式下定量检测。lC-MS/MS定量限为0.01Mg/kg,线性范围为10~500μg/l,相关系数r2>0.99,平均回收率为66.8%~98.7%,相对标准偏差为1.9%~7.6%(n=6)。A method to analyze melamine residue in candies was established by using triple quadurupole liquid chromatography-tandem mass spectrometry(LC-MS/MS).Trichloroacetic acid was used to extract the target analyte.The CAPCELL PAK CR column was used for separation and the multiple reaction monitoring(MRM) positive ion mode was used for the determination.The limit of detection was 0.01mg/kg for LC-MS/MS.The coefficient of linear calibration curve was over 0.99 within the melamine concentration range of 10~500μg/L.The average recoveries of melamine by this method were 66.8%~98.7%,and the RSDs ranged from 1.9%~7.6%(n=6
Research on photovoltaic performance of Cu2ZnSnS4 and fabrication by solution chemical method
Cu2ZnSnS4(CZTS) is pr oved to be one of the ideal photoabsortion materials in the field of thin film solar cells,owning to its abundant resources,environment friendly,fascinating optoelectronic properties and so on.The crystal structure and photovoltaic
锂离子电池有机硅电解液
有机硅电解液具有优良的热稳定性、低可燃性、无毒性、高电导率和高分解电压等优点,近年来成为了锂离子电池新型电解液的研究热点。本文综述了有机硅电解液的研究进展,重点介绍了聚醚有机硅电解液的设计合成、物理化学性能、与电解质盐和电极材料的匹配性关系及其在电池中的性能表现;简述了有机硅功能化电解液添加剂的研究进展,如成膜添加剂、阻燃添加剂、吸酸吸水添加剂等;最后对有机硅电解液的进一步研究趋势和应用前景进行了展望
原位模板牺牲法制备富锂锰基材料lili02ni02mn06o2及性能研究
采用原位模板牺牲法、溶胶凝胶法和限域共沉淀法三种不同方法分别制备了不同形貌的富锂锰基材料LiLi0.2Ni0.2Mn0.6O2(LLO)纳米颗粒。电化学测试和分析显示,使用原位模板牺牲法制备的LLO样品具有更好的比容量、循环稳定性和倍率性能,原因是:(1)制备出具有空心结构的微米球,每个空心球中的空腔能够为Li+储存提供更多的位点,有利于提高材料的比容量;(2)空心结构的微米球具有更大的比表面积和较短的锂离子扩散路径的优点,有效提高了材料的倍率性能;(3)空心结构中的孔隙能减小体积效应对材料的影响,从而保证了结构的稳定性,提高电极材料的循环性能
Synthesis and Characteristics of Lithium-Rich Manganese-Based Material Li[Li0.2Ni0.2Mn0.6]O2by in Situ Template-Sacrificial Method
采用原位模板牺牲法、溶胶凝胶法和限域共沉淀法三种不同方法分别制备了不同形貌的富锂锰基材料Li[Li0.2Ni0.2Mn0.6]O2(LLO)纳米颗粒。电化学测试和分析显示,使用原位模板牺牲法制备的LLO样品具有更好的比容量、循环稳定性和倍率性能,原因是:(1)制备出具有空心结构的微米球,每个空心球中的空腔能够为Li+储存提供更多的位点,有利于提高材料的比容量;(2)空心结构的微米球具有更大的比表面积和较短的锂离子扩散路径的优点,有效提高了材料的倍率性能;(3)空心结构中的孔隙能减小体积效应对材料的影响,从而保证了结构的稳定性,提高电极材料的循环性能
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