关键词： 磷酸铁锂   正极材料   动力电池   生产项目   新能源材料   电池材料   科技项目   安全性能  

摘要： 一、项目背景 新型锂动力电池正极材料磷酸铁锂，属新能源材料中锂离子电池材料类，系国家重点支持发展的高新科技项目，磷酸铁锂具有安全性能好、价格便宜和能量密度高等特点，在电动车辆、电动工具、电网调节和储能等领域应用前景广阔。

关键词： LiFePO4   PSS   Hydrothermal method   Poly (sodium 4-styrenesulfonate)  

摘要： In this study, we prepared LiFePO4-poly (sodium 4-styrenesulfonate) (PSS) composite by the hydrothermal method and ball-milling process. Different wt% PSS were added to LiFePO4. The cathode electrodes were made from mixtures of LiFePO4-PSS: SP-270: PVDF in a weighting ratio of 70%: 25%: 5%. LiFePO4-PSS powders were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The electrochemical properties of LiFePO4-PSS/Li batteries were analyzed by cyclic voltammetry, charge/discharge tests, and AC impedance spectroscopy. A Li/LiFePO4PSS battery with 4.75 wt% PSS shows the best electrochemical properties, with a discharge capacity of 128 mAh/g.

关键词： Carbon Conductive additives   graphene nanosheets   LiFePO4   lithium-ion batteries  

摘要： Carbon black, multi-walled carbon nanotubes and graphene nanosheets were respectively added to LiFePO4 particles as conductive additives to investigate the influence on the electrochemical performance. The specific surface area and pore size distribution of LiFePO4 particles were measured by N-2 absorption. The microstructure of carbon conductors and LiFePO4 sample were characterized by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The results of electrochemical measurements indicated that LiFePO4 mixed with graphene nanosheets exhibited the best electrochemical performance, of which the specific capacity was up to 146 mAh g(-1) at 0.1 C and 125 mAh g(-1) at 1 C. Graphene nanosheets showed plane-to-point electric contact with LiFePO4 particles, owing to the unique two-dimensional planar structure. In this work, it was demonstrated that graphene nanosheets will be the most promising carbon conductive additives in cathode materials for lithium-ion batteries.

关键词： Heat effect   thermo electrochemistry   LiFePO4   lithium-ion battery   electrochemical calorimetry  

摘要： The heat effects of lithium-ion battery cathode could substantially affect the safety and attenuate lifetime of lithium-ion battery. In order to disclose the thermo-electrochemical behaviors of LiFePO4 battery during charge-discharge process at various rates at 30 degrees C, electrochemical-calorimetric measurements were employed in this study. The results showed that LiFePO4 battery had a smaller polarization and a better reversibility at low rate (0.1C, 0.2C, 0.5C). With the increasing of the rate structure of cathode material LiFePO4 was partially destroyed and impurities, like Li3PO4 and FeP2, appeared at rate 1.0C and 2.0C. Formation of these impurities resulted in electrochemical performance deterioration of battery. The charge-discharge process of LiFePO4 battery accompanied exothermic process and endothermic process at low rate (0.1C, 0.2C). When the rate increased to 1.0C, only exothermic phenomena existed. With the rate increasing heat production rate and the enthalpy change during charge-discharge process of LiFePO4 battery increased. These suggest that appropriate rate for battery should be choose in order to avoid safety problem, which initiated by internal heat accumulation of battery.

关键词： MOSSBAUER spectroscopy   ELECTROCHEMICAL analysis   LITHIUM compounds   IRON ions   SAMPLE preparation (Chemistry)   LITHIUM-ion batteries  

摘要： The valency state and local coordination of Fe ions of four industrial samples and a sample of cathodic materials for recharcheable lithium ion batteries obtained using an original technology of St. Petersburg State Technological Institute (Technological University) were studied using the Mossbauer effect on the Fe-57 isotope. It was found that the main valency state for more than 90% of iron ions was Fe2+. The values of isomer shift delta = 0.96-0.98 mm/s and quadrupole splitting sigma = 2.88-2.93 mm/s for Fe2+ ions coincide with the values for compounds with the structure of olivine LiFePO4 and occupy positions in highly distorted FeO6 octahedrons. Fe3+ ions are in octahedral and/or tetrahedral local positions.

关键词： 锂离子动力电池   软包   电动   产业化   动力型锂离子电池   制作技术   磷酸铁锂   车用  

摘要： 技术简介：该项目结合目前纯电动车用锂离子动力电池的需要，采用磷酸铁锂一石墨为基本原料和软包制作技术制备锂离子动力电池。动力型锂离子电池年产规模为2000万Ah。

关键词： 许可协议   技术专利   磷酸铁锂   巴斯夫   电池材料   业务部门  

摘要： 巴斯夫全球电池材料业务部门近日宣布，已与位于瑞士穆滕茨（Muttenz）的科莱恩集团附属公司LiFePO4＋C Licensing AG签署一份技术许可协议，获得磷酸铁锂（LFP）电池材料的全球生产与销售权。

关键词： 磷酸铁锂   电池组   不一致性   串联   并联  

摘要： 为研究磷酸铁锂电池在成组过程中遇到的不一致性的问题,并指导电池成组方式的选择,进行了相关试验和建模。用同一种磷酸铁锂电池,经过不同的工况,然后按不同的方式成组,来模拟实际电池组的不一致性。对Rint模型进行改进,在单体模型的基础上,构建了电池组串联、并联和混联模型。使用热模型验证并联模型下的电流分布。研究发现:由于单体间内阻不一致,并联单体之间,工作电流分布并不均匀,甚至可能造成安全问题。由此提出了"不一致性系数"的概念。通过计算各种混联方式的不一致性系数,建议采用能保证并联在一起的单体或模块内阻尽可能相似的连接方式。

关键词： 锂离子电池   磷酸铁锂   直流内阻   测试方法  

摘要： 研究了电动自行车用圆柱形动力磷酸铁锂锂离子电池在不同电流、不同测试持续时间下的直流内阻。分析了电池SOC、充电电流和放电电流、持续时间以及电流和时间的交互作用对电池直流内阻的影响。研究表明,测试电流和持续时间对电池的直流内阻影响比较大,在30%～80%SOC范围内相同测试条件下电池的直流内阻变化不大;放电测试条件下的直流内阻略高于充电测试条件下的直流内阻;在0～10s内,电池的直流内阻测试值与测试时间呈线性变化关系;容量型电池与功率型电池的直流内阻变化规律相同。

关键词： 磷酸铁锂   材料性能   正极   结构   微米   综合性能   中国市场   供应商  

摘要： 国际上生产综合性能良好的磷酸铁锂产品的企业主要分布在美国和加拿大。但国外供应商为追求更高的附加值不愿意向中国市场单独供应磷酸铁锂材料。