STUDY ON THE EFFECT OF SOME FACTORS ON THE CATHODE PERFORMANCE OF LITHIUM-ION BATTERIES

在锂离子电池中，阴极是一个控制性能的关键电极。阴极在很大的程度上控制电池的充放电性能，阴极的放电电位控制着电池的放电平台；电池在不同温度的阻抗主要来自于阴极阻抗的贡献；在电池充放电循环过程中性能的衰退主要由于电化学反应阻抗的增加所致，而反应阻抗增加又主要由阴极的反应阻抗增大所贡献。迄今为止大量的研究集中在以半电池为对象的单电极行为，对实际电池体系的阴极行为研究较少，相关的工艺基础研究也不多，而对实际电池体系阴极行为的研究更具有必要性和实用性。 本文在对锂离子电池、特别是聚合物锂离子电池的性能及工艺技术进展进行评述、对锂离子电池不同阴极材料的产业化可行进行了对比分析的同时，对锂离子电池工艺、电...In lithium-ion battery, cathode is a key electrode to control battery performance. Cathode controls the charging-discharging characteristics, including discharging platform. Cathode impedance mainly contributes to battery impedance in different temperature environment; Cathode impedance increase is also the main cause of battery cycle fading. But till now, a great deal of research focus on single ...学位：理学博士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：B20012501

The applied development of ferrate used as cathode materials

介绍了高铁酸盐的研究发展概况。结合高铁酸盐在水溶液体系和非水溶液体系电池中的应用,对将其作为一种新型正极材料的电化学特性进行了讨论。The recent development survey of ferrate was reviewed especially as cathode materials in batteries. The application as active materials in aqueous and non-aqueous battery system was presented. It was shown that the ferrate could be used as cathode active material in alkaline Zn/ferrate( Ⅵ), MH/ferrate(Ⅵ㈡) and lithium batteries and possessing of higher capacity than Zn/MnO? and Li/LiMn2O4 batteries respectively. However the stability of these batteries was not satisfactory due to the characteristics of ferrate. It would be key work to improve the stability of ferrate ongoing process

分子内电荷转移荧光探针法测定表面活性剂的临界胶束浓度

研究了分子内电荷转移荧光体4-二甲氨基查尔酮(DMAC)在表面活性剂水溶液中的荧光光谱。观察到随表面活性剂浓度增大,DMAC 的荧光光谱先红移然后蓝移,而荧光强度呈“S”型变化并于光谱位移方向转折处突跃。突跃处对应的表面活性剂浓度即为其临界胶束浓度(cmc)。结果表明由该法测定的 cmc 与已报道值符合,说明方法的可行性与准确性。用该法测定表面活性剂/β-环糊精混合体系的 cmc,表明β-环糊精的存在诱导了胶束的形成

Preparation and electrochemical performance of Ni-Sn alloys

[中文文摘]作为锂离子电池用非碳类负极材料,合金或金属间化合物备受关注。合金材料在循环过程中的体积变化是一个致命缺点。从抑制体积变化的角度出发,根据"BufferMatrix"的概念,将活性相植入到非活性相载体中。镍作为非活性相,锡作为活性相,用不同的方法制备了非晶态锡镍合金和晶态锡镍合金(Ni3Sn),研究了其形貌特征、晶体结构及电化学性能。在高温下用氢气还原的Ni3Sn具有稳定的晶体结构、较高的比容量(300mAh/g)和优良的循环性能。[英文文摘]As a carbon alternative anode material for Li-ion battery, alloys or inter-metal compounds were focused intensively.The alloy materials had a fatal disadvantage that the volume swelling existed during the cycles.The active materials embedded in inactive carrier based on the concept of "Buffer Matrix" to restrain the volume swellings. Ni as an inactive phase and Sn as an active phase, amorphous Ni-Sn alloy and crystalline Ni_3Sn were synthesized employing different methods which led to different morphology.The morphology characteristics , crystal structures and electrochemical performance of the materials were investigated.Ni3Sn reduced by H2 at high temperature had a stable crystal structure ,higher specific capacity (300 mAh/g) and excellent cycle performance.973项目(2002CB211804); 国家自然科学基金(20373058); 福建省科技项目(2003H044); 厦门市科技计划项目(3502Z2001234)

Development progress of low-temperature lithium-ion batteries

综述了低温锂离子电池近几年的研究进展。对比分析了不同溶剂、电解质及添加剂对锂离子电池低温性能的影响及作用机理,同时也讨论了低温环境中电极结构与表面反应对锂离子电池低温性能的影响。综合近年来的发展趋势,指出了低温锂离子电池的发展方向。The development of low temperature lithium ion batteries in recent years was reviewed. The influence and its mechanism of different solvents,salts and additives of low temperature electrolyte were compared,the electrode structure and electrode surface reaction in low temperature environment were also discussed. Some directions of research on low temperature lithium batteries were presented according to recent developing trend.浙江省技术创新项目资助(2007-50);; 杭州市高技术产业化项目资助(2007-13

Study on overcharging additives of Li-ion battery

[中文文摘]环己基苯和二甲苯作为耐过充添加剂加入锂离子电池电解液中。环己基苯和二甲苯分别在4.70 V、4.66 V(vs.Li/Li+)处发生电聚合反应。聚合物几乎全部覆盖在隔膜表面,阻断了反应,改善了电池的安全性。添加5%添加剂的电池,均可耐3C1、0 V过充电,且对电池正常充放电时的电化学性能影响很小。[英文文摘]Cyclohexyl benzene(CB) and xylene as overcharging additives were added into Liion battery electrolyte.CB and xylene could be electrochemically polymerized at 4.70 V and 4.66 V(vs.Li/Li~+),respectively.The polymer mainly deposited on the separator,restrained the reaction and improved the safety performance of the battery.The batteries with the additives could resist overcharge of 3 C,10 V when the content of additive was 5%.There was only a slight influence on the electrochemical performance of the batteries with normal charge-discharge.973项目(2002CB211800); 国家自然科学基金(20373058)；厦门市科技计划项目(3502Z20055018)

Preparation and properties of nano-structured α-MnO_2 as electrode material of supercapacitor

[中文文摘]用KMnO4和MnSO4水溶液作为原料,用液相沉淀法制备无定形-αMnO2.nH2O。对样品进行比表面积测定(BET)、XRD、SEM等测试。通过循环伏安法和恒流充放电测试研究了样品的电化学行为。合成的无定形-αMnO2.nH2O在0.5mol/L的Na2SO4电解液中,在0~0.9 V(vs.SCE)范围内,电流为10 mA,2 mV/s的扫描速度下的比电容可达126.4 F/g。无定形-αMnO2.nH2O是较好的超级电容器电极材料。[英文文摘]Amorphous α-MnO_2·nH_2O was synthesized with chemical coprecipitation method by using KMnO_4 and MnSO_4(aqueous) solution as raw materials.The sample was characterized by BET,XRD and SEM.The electrochemical characteristics of the sample were characterized by CV and constant current charge-discharge tests.The specific capacitance of the amorphous α-MnO_2·nH_2O was 126.4 F/g in 0.5 mol/L Na_2SO_4 electrolyte at the scan rate of 2 mV/s,the current of 10 mA,in the range of 0～(0.9 V)(vs.SCE).The amorphousα2MnO2·nH2O was an excellent electrode material for supercapacitor.973项目(2002CB211800); 国家自然科学基金(20373058); 福建省科技项目(2003H044)

Development of cathode material LiFePO_4 in lithium ion battery

[中文文摘]LiFePO4作为一种新型的锂离子电池正极材料,安全性好,价格低廉,环境友好,循环性能稳定。结合本实验室的研究工作,从合成方法,表征手段,循环性能和电导率等方面综述了近年来LiFePO4的发展概况,并提出了LiFePO4进一步可能的发展趋势。[英文文摘]As a cathode material of lithium ion battery, LiFePO4 possesses some excellent characteristics such as good safety, low cost, environment friendly and satisfactory cycle stability. In this paper, the development of LiFePO4 in recent years is discussed in terms of synthesizing methods, characterization ways, cycling performance and electronic conductivity. The prospect of LiFePO4 in the future is also presented.973项目(2002CB211800); 国家自然科学基金(20373058); 福建省科技项目(2003H044)资助

Influence of cathode conductive agent content on lithium ion battery performance

研究了不同阴极导电剂含量对锂离子蓄电池的充放电性能和阻抗性能的影响。对锂离子蓄电池交流阻抗谱测定表明,聚合物锂离子蓄电池阴极在充放电循环过程中,其电化学反应阻抗的变化值与电极中导电剂含量有一定的相关性,根据这一相关性得到一种新的确定锂离子蓄电池阴极中导电剂最佳含量的方法。The influence of cathode conductive agent content to battery performance and AC impedance were investigated. The determination result of AC impedance spectrum of polymer lithium ion battery shows that the variation value of cathode charge transfer impedance is relative to the conductive agent content in this cathode. A new method of calibration of optimal cathode conductive agent content is presented according to this relativity.厦门市科技计划项目(3502Z2001234);; 973项目(2002CB211804);; 福建省科技项目(2003H044

Polymer lithium-ion battery in development(I)——Battery characteristics improvement

介绍了聚合物锂离子电池性能改进的近况。重点针对电池的比能量 ,充放电特性 ,循环性能 ,安全性能等方面的进展进行了对比。讨论了目前聚合物锂离子电池工业生产中需要改进的问题和发展的方向The development and characteristics of polymer lithium ion batteries were reviewed with 15 references. The review focused on comparison of the specific energy, charging discharging characteristics, cycling performance and safety characteristics of these batteries. The difficulties and developing aspects of polymer lithium ion batteries were discussed国家信息产业部通信产品配套元件开发专项基金资助 (信部产 2 0 0 0 -878