一种电动自行车电池过充保护装置设计

目前市场上的电动自行车所配备的充电器大多没有充满后自动断电保护的功能,现提出一种电池过充保护装置,包括绝缘外壳和内部控制电路。通过橡胶绷带将绝缘外壳固定于电池充电器的顶部,内部的绿光增强型光电二极管紧靠电池充满LED指示灯,当接收到绿光后首先进行1~2个小时的浮充延时,继而触发系统内部的继电器自动切断充电器的电源,保护电池。内部电路的仿真结果显示了该装置设计的正确性。装置具有电路简单、功耗低、安装方便、成本低等优点,并且不需要对现有的充电器进行改造。     

5-硝基水杨酸的合成新工艺研究

以邻氯苯甲酸为原料,采用混酸硝化生成中间体2-氯-5-硝基苯甲酸,再水解生成目标产物5-硝基水杨酸.重点对硝化反应的混酸配比、反应温度及水解反应的反应温度、反应时间进行了考察,得到了硝化反应混酸配比为浓硫酸∶浓硝酸(摩尔比)＝9∶1,反应温度0 ℃,反应时间为8 h的较优工艺条件,收率为95.7%.水解反应温度为140℃,反应时间为16 h,收率为98.3%.反应后产品用适量乙醇水溶液重结晶得到5-硝基水杨酸,含量≥99.8%(HPLC).     

5V锂离子电池正极材料的制备和电化学性能研究

用液相法合成出用锂和镍取代的尖晶石锂锰氧化物正极材料.用XRD和FTIR对其进行了表征,并探讨了其在有机电解液的电化学性能.研究结果表明:在锂锰氧化物掺入适量的镍(锰∶镍的摩尔比为1.4∶0.6)可以改善尖晶石LiMn2O4的循环性能,提高放电平台,使其大部分容量往高电位方向移动,电池的放电电压提高,这样的材料适合做5V电池的正极材料.     

电解液添加纳米氧化铝对锂离子电池性能影响

将纳米氧化铝粉体加入到锂离子电池电解液中,通过充放电测试、充放电循环测试以及交流阻抗分析,研究纳米氧化铝的添加量对锂离子电池电化学性能的影响.结果表明,在电解液中添加一定量的纳米氧化铝粉体可以有效提高电解液的电导率,减小电荷传递电阻,提高锂离子电池的电化学性能.当纳米氧化铝添加量为1.0％(质量分数)时,锂离子电池充放...     

锂离子电池电解液添加剂联用技术

阐述在锂离子电池电解液中将氟代碳酸乙烯酯（FEC）和四氟硼酸锂（LiBF4）两种添加剂联合使用,通过电解液的物理指标测试、电池在高温条件下的充放电及循环性能的测试,重点研究了组合添加剂与锂离子电池性能的关系,以及对SEI膜形成与稳定的影响.结果表明,使用复合添加剂有明显的优势,同时将FEC和LiBF4作为锂离子电池电解液的添加剂,可利用添加剂间的协同作用来改善锂离子电池的高温性能.     

2-硝基-5-苄氧基甲苯的合成

2-硝基-5-苄氧基甲苯是有机中间体,可以进一步采用Reissert法合成吲哚类化合物。以间甲酚为原料,采用一步硝化法,先0℃以下亚硝化,再程序升温至45℃氧化得到4-硝基间甲酚粗品。产品精制后收率为76.5%,高于两步硝化法的收率52%。探索了苄基三乙基氯化铵、四丁基溴化铵、OP-10、聚乙二醇200和聚乙二醇600等几种相转移催化剂对该步反应收率的影响。聚乙二醇600的相转移催化作用明显,精制后产品收率在89%以上。4-硝基间甲酚与氯化苄在乙醇钠作催化剂的条件下制备2-硝基-5-苄氧基甲苯,收率为86.9%。合成2-硝基-5-苄氧基甲苯的总收率达77%以上。通过熔点、红外和气质联用对产品进行了表征。     

碳酸亚乙烯酯对聚合物锂离子电池的影响

研究了碳酸亚乙烯酯(VC)作为添加剂对聚合物锂离子电池性能的影响.发现聚合物锂离子电池有机电解液中加VC以后,降低了电池的内阻,提高了循环性能与高低温放电性能.循环伏安的测试结果表明,VC加入以后,电位在-1.5~-2.0 V出现了一个可逆峰,使得电池的初期不可逆容量降低.交流阻抗测试结果证明,VC的加入降低了碳电极界面电阻、电荷传递反应电阻以及溶液扩散电阻,使锂离子的迁移变得容易;同时提高了SEI膜的致密性,从而改善了电池的性能.     

5-硝基愈创木酚钠的合成

以愈创木酚为原料，醋酸酐为酰化剂、硝酸-冰醋酸为硝化剂，分别进行乙酰化、硝化反应，经NaOH溶液水解，制得5-硝基愈创木酚钠。讨论了温度和硝化剂对硝化反应的影响及NaOH的质量分数对水解反应的影响。结果表明：在硝化反应时间为3h、反应温度为80～90℃、NaOH的质量分数为15％的条件下，可得总收率为65％的5-硝基愈创木酚钠。     

锂离子电池保护电路应用中存在的问题及改进

针对单节锂离子电池保护电路在应用中保护IC和CMOS容易损坏的问题,分析了单节锂离子电池保护电路的工作原理,通过外围电路的改进设计,对锂离子保护IC和CMOS起到有效的保护作用。     

锂离子电池负极材料Li_4Ti_(5-x)Co_xO_(12)的结构与电化学性能

主要采用溶胶凝胶法合成Li4Ti5-xCoxO12负极材料,通过XRD、SEM和电化学测试手段,系统的研究了尖晶石型Li4Ti5-xCoxO12的结构和电化学性能.结果表明:0.06≤x≤0.24的样品均为纯相尖晶石型结构,掺杂Co3+对晶粒的生长有抑制作用,但团聚现象明显;引入Co元素降低了样品的首次放电比容量,但是没有影响样品的循环稳定性.     

Effect of Overcharge on Electrochemical Performance of Sealed-Type Nickel/Metal Hydride Batteries

The effects of overcharge on electrochemical performance of AA size sealed-type nickel/metal hydride（Ni/MH） batteries and its degradation mechanism were investigated. The results indicated that the relationship between the effects of different overcharge currents on the increasing velocity of inner pressure and the degradation velocity of cycle life and discharge voltage remains in almost direct proportion. After overcharge cycles, the positive electrode materials remain the original structure, but there occur some breaks because of the irreversible expand of crystal lattice. And the negative electrode alloy particles have inconspicuous pulverization, but are covered with lots of corrosive products and its main component is rare earth hydroxide or oxide. These are all the main reasons leading to the degradation behavior of the discharge capacity and cycle life of Ni/MH batteries.     

纳米CoSb作为锂离子电池新型负极材料的研究

用溶剂热法合成了纳米尺寸的CoSb合金粉末，并研究了该合金粉末作为锂离子二次电池新型负极材料的电化学性能.合成的合金粉末经过了X射线衍射 (XRD)、透射电镜 (TEM) 和场发射扫描电镜 (FESEM) 的表征,研究发现，该合金粉末的首次可逆容量达到362 mA·h/g，经过了20个循环后，其可逆容量仍保持在320 mA·h/g. 与用悬浮熔炼/球磨工艺所得的微米尺寸的合金粉末相比，用溶剂热方法制得的纳米CoSb粉末的可逆容量和循环性能均显著提高.这是因为，纳米CoSb粉末颗粒尺寸较小，在充放电过程中绝对体积变化较小 (尤其在最初的几个循环中)，这显著地减缓了活性材料的粉化和剥落.     

Purification process of coal-based coke powder as anode for Li-ion batteries简

A process of purification of coal-based coke powder as anode the treatment of coke powder with dilute hydrofluoric acid solution, for Li-ion batteries was attempted. The process started with followed by united-acid-leaching using sulfuric acid and hydrochloric acid. The effects of altering the hydrofluoric acid addition, hydrofluoric acid concentration, contact time, temperature and acid type were investigated. A minimum ash content of 0.35% was obtained when proper conditions were applied. The electrochemical performance of purified coke powder shows greatly improved electrochemical performance. The as-purified coke powder presented an initial reversible capacity of 257.4 mAh/g and a retention rate of 95% after 50 cycles. The proposed purification process paves a way to prepare a promising anode material with good performance with low cost of coke powder for Li-ion batteries.     

新型锂储藏合金负极材料研究进展

合金型锂离子电池负极材料由于容量高、安全性好而受到了极大的关注，最有希望取代碳材料在下一代高性能锂离子电池中得到应用．笔者着重介绍了以锡合金为代表的锂储藏合金的研究进展，以及最新的纳米技术和薄膜技术在研究过程中的应用．由于新技术的应用，解决了合金材料在充放电过程中由于体积膨胀而粉化的缺点，锂储藏合金材料的研究取得了突破性的进展，循环寿命已经达到了300周以上，离实际应用仅一步之遥．锡基合金负极材料是最有竞争力的下一代锂离子电池负极材料之一。     

A Novel Modification Approach for Natural Graphite Anode of Li-ion Batteries

To improve the rate caqability and cyclability of natural graphite anode for Li-ion batteries, a novel modifwatio, approach was developed. The modification approach included two steps:(a) high-energy ball milling in a rotary aatoelave containing alumina balls, H3PO4 and ethanol;( b ) coating with pyrolytic carbon from phenlic resin. The treated graphite sluws obrious improvement compared with the original natural graphite in electroehemical properties such as cyclahility and rate capability, especially at high current density. The primaryreasons leading to the improvement in rate capability and cyclability are that the diffusion impedance of Li^ in graphite is reduced due to the fact that P filtered into graphite layers can mildly increase interlayer distances, and the fact that the structural stability of graphite surface is enhanced since the coated pyrolytic carbon can depress the co-intercalation of solvated lithium ion.     

Preparation and electrochemical properties of polymer Li-ion battery reinforced by non-woven fabric

A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene was prepared by evaporating the solvent of dimethyl formamide, and non-woven fabric was used to reinforce the mechanical strength of polymer electrolyte and maintain a good interfacial property between the polymer electrolyte and electrodes. Polymer lithium batteries were assembled by using LiCoO2 as cathode material and lithium foil as anode material. Scanning electron microscopy, alternating current impedance, linear sweep voltammetry and charge-discharge tests were used to study the properties of polymer membrane and polymer Li-ion batteries. The results show that the technics of preparing polymer electrolyte by directly evaporating solvent is simple. The polymer membrane has rich micro-porous structure on both sides and exhibits 280% uptake of electrolyte solution. The electrochemical stability window of this polymer electrolyte is about 5.5 V, and its ionic conductivity at room temperature reaches 0.151 S/m. The polymer lithium battery displays an initial discharge capacity of 138 mA·h/g and discharge plateau of about 3.9 V at 0.2 current rate. After 30 cycles, its loss of discharge capacity is only 2%. When the battery discharges at 0.5 current rate, the voltage plateau is still 3.7 V. The discharge capacities of 0.5 and 1.0 current rates are 96% and 93% of that of 0.1 current rate, respectively.     

复合凝胶聚合物电解质的制备及电化学性能

以偏氟乙烯和六氟丙烯共聚物为基体,通过与聚甲基丙烯酸甲酯共混,加入导电盐LiPFs、增塑剂聚乙烯吡咯烷酮,制备了高电导率的复合凝胶聚合物电解质（CGPE）。用红外光谱测试了聚合物电解质膜的结构,用交流阻抗法测试了CGPE的导电性能,用线性扫描伏安法研究了它的电化学稳定性。测试了以CGPE为电解质制备的锂离子电池的充放电性能。结果表明,当聚甲基丙烯酸甲酯（PMMA）质量分数为20％时,CGPE电导率大于10^-3s／cm,在4．65V电化学窗口以下稳定。以磷酸亚铁锂为正极时,在0．1C和0．2C倍率下放电时,聚合物电解质电池的首次放电容量分别为138mAh／g和98．3mAh／g。     

镉镍蓄电池复合电解液的工艺研究

为改善具有特殊用途的方形开口镉镍蓄电池的大电流及低温放电性能,采用正交试验方法进行了蓄电池配套复合电解液的研究.试验表明:在浓度为1.30 g/ml的KOH溶液中加入一定量的LiOH.H2O、羧甲基纤维素CMC以及乳化剂能有效改善蓄电池大电流及低温放电性能,使蓄电池在-10℃的低温下起动放电电压达到19V以上.