新型锂离子电池正极材料LiVOPO4的制备与表征

Novel lithium-ion battery cathode material LiVOPO₄ was synthesized by sol-gel method using lithium hydroxide, ammonium metavanadate, phosphoric acid and citric acid as raw materials. The microstructure, surface morphology and electrochemical properties were characterized by various electrochemical methods in combination with thermogravimertric (TG) analysis and differential thermal analysis (DTA), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscope (SEM). Results show that the sample obtained by calcinating at 650 ℃ for 6 h is made up of uniform particles with size of 2～3 μm. The first discharge, charge capacity and columbic efficiency of LiVOPO₄ is 137.1 mAh·g^-1, 146.1 mAh·g^-1 and 93.8%, respectively. After 80 cycles the discharge capacity is kept at 130.4 mAh·g^-1, which is 95.1% of the first discharge capacity, and the capacity loss per cycle was only 0.061%, suggesting the LiVOPO₄ derived by this method is a promising cathode material for lithium ion batteries.     

Inhibition of Model Compound of Purple Acid Phosphatases on Growth of Aerobacter aerogenes Investigated by Microcalorimetry

Ironisoneofthefourteentypesofessentiallybiologi caltraceelements .Ironplaysanimportantroleinlivingbodyanditwasregardedastherequiredtraceelementforlife .Manystudiesindicatethatdeficiencyorexcessofironmaybethecauseofmanydiseases .Furthermore ,ironisactivecenterofpigmentoxidase ,andsuccinicdehydroge nase ,etc .Consequently ,thestudyoftheinfluenceofironanditscompoundsonmicroorganismissignificantforun derstandinglifephenomenon .1Inhibitoryorantibioticactionofpurpleacidphos phatases (PAPs)hasnotbe…     

锂离子正极材料Li(Ni_(1/3)Co_(1/3)Mn_(1/3))_(1-x)Al_xO_2的制备及电化学性能

以化学法合成Li(Ni1/3Co1/3Mn1/3)1-xAlxO2系列正极材料(0≤x≤0.1);用X射线衍射仪、扫描电子显微镜和充放电仪研究系列产物的晶体微观结构、表面形貌以及电化学性能,研究不同Al含量参杂对材料性能的影响。结果表明,合成的材料均属于六方晶系,R3m空间群,保持α-NaFeO2层状结构相;Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2的首次放电容量166.30 mA·h/g,在2.5~4.5 V区间60次循环后比容量衰竭率为4.43%。通过对比Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2和Li(Ni1/3Co1/3Mn1/3)O2的电极阻抗,分析它们的电化学循环机理,可知掺杂Al后的正极材料适合大倍率放电。     

C60和C70在几种溶剂中的溶解度与温度的关系

溶解度是富勒烯C6O和C7O的基本物理化学常数之·．自电弧法合成富勒烯成功以后＊；人们就很重视C60和C7O在各种溶剂中的溶解性能．由于在分离、分析富勒烯和研究其化学反应时，往往是在溶液中进行的，因此，不少科学家很快就测定TC60和C70室温下在多种有机溶剂中的溶解度［’－     

钌/酸共催化邻氨基苯甲醇和芳基端炔合成喹啉衍生物

以邻氨基苯甲醇为原料进行催化脱氢反应,经过对催化体系的一系列筛选,最终采用[RuCl₂(p-cymene)]₂/AgOTf共催化体系,使邻氨基苯甲醇发生催化脱氢和芳基端炔发生交叉偶联反应,并以39%~47%的收率获得合成一系列2-芳基喹啉衍类生物,发展了邻氨基苯甲醇与芳基末端炔烃合成喹啉衍类生物的新方法,是对喹啉类衍生物合成方法的一个重要补充。     

火焰原子吸收光谱法测定电解锰电解液中铁钴镍

在标准溶中加入匹配的硫酸铵和硫酸锰溶液,用氨水调节ＰＨ至中性后,用火焰原子吸收光谱法直接测定电解锰电解液中铁、钴和镍含量,获得了满意的效果,其倍比试验,标准曲线法、标准加入法结果相吻合,样品加标回收率为９４．８％－１０６．４％,相对标准偏差为２．１％－３．１％。方法简便、快速,运用于工厂快速分析。