检索结果-南通市图书馆

无机材料学报 2012年第9期27卷 997-1002页

作者： Deng Hong-Gui Jin Shuang-Ling He Xing Zhan Liang Qiao Wen-Ming Ling Li-cheng E china Univ Sci & Technol State Key Lab Chem Engn Shanghai 200237 Peoples R China Shanghai Univ Sci & Technol Sch Mat Sci & Engn Shanghai 200093 Peoples R China

lifepo_4 nanoparticles coated with a carbon layer were synthesized by a hydrothermal reaction-calcination process, using Fe_2O_3 as an iron source and ascorbic acid as carbon source. The amount of ascorbic acid have an effect on the structure, phase and carbon amount of the final product. With 1 g ascorbic acid used in the reaction, the particle sizes of synthesized lifepo_4/c nanocomposites are in a range of 220–280 nm. Using as the cathode materials for the lithium-ion batteries, the as-prepared material shows high capacity and good cycle stability (159 mAh/g at 0.1c over 500 cycles), as well as good rate capability.

关键词： lifepo4/c 无机材料化学材料化学工业

Electrochemical property of lifepo4/c composite cathode with different carbon sources

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2018年第9期37卷 743-749页

作者： Xin Li Yu Zhi Jiang Xi Kun Li Hai Xia Jiang Jun Long Liu Jun Feng Shi Bin Lin Xin Guan Shenyang Ligong University Shenyang 110159 China

To improve the performance of battery cathode materials that consist of carbonaceous organic material, carbon coatings on lithium iron phosphate （lifepo4/c） materials were synthesized by different carbon sources. lifepo4/c was synthesized by a combination method of sol-gel and gas-phase diffused permeation. LiFeO4/c materials were prepared by coating different carbon con- tents. High-performance composite materials were pre- pared by combining carbon with element doped by two modified methods. The elements of Fe and c came from Fe3＋ and sucrose, glucose, citric acid. Thermogravimetry- differential thermal analysis （TG-DTA）, X-ray diffrac- tometer （XRD）, scanning electron microscope （SEM）, cycle voltammetry （cV）, and charge-discharge test were used to characterize and test the surface morphology, structure, and electrochemical performance. The results show that lifepo4/c synthesized with sucrose has higher specific discharge capacity than the other materials. The specific discharge capacity of this material is 84.27 mAh.g-1. The capacity retention could attain 94 % of the initial discharge capacity after 30 cycles, showing good electrochemical performance.

关键词： Solgel Gas-phase diffused permeation lifepo4/c Sucrose citric acid

Influence of synthesis parameters on the properties of lifepo4/c cathode material

在线全文

学校读者我要写书评

暂无评论

chinese Journal of chemical Engineering 2016年第3期24卷 427-432页

作者： Zhengwei Xiao Yingjie Zhang Guorong Hu Faculty of Metallurgical and Energy Engineering Kunming University of Sdence and TechnologyKunming 650093China School of Metallurgy and Environment Central South UniversityChongsho 410083China

The influence of sintering temperature,carbon content and dispersive agent in ball-milling was investigated on the properties of Li Fe PO_4/c prepared using Fe_2O_3,NH_4H_2PO_4,Li_2cO_3 and glucose via solid state reaction.X-ray powder diffraction,scanning electron microscopy and charge–discharge test were applied to the characterization of the Li Fe PO_4/c samples synthesized under different conditions.Sintering temperature affects the crystallite/particle size and degree of crystallinity of LiF eP O_4,formation of Fe_2 P and maintenance of carbon in LiF e PO_4/c.carbon maintenance is favored by low sintering temperature,and 700 °c is optimum for synthesis of LiF eP O_4/c with superior electrochemical performance.A higher carbon content in the range of 4.48%–11.03% results in a better rate capability for Li Fe PO_4/c.The dispersive agent used in ball-milling impacts the existent state of carbon in the final product which subsequently determines its charge–discharge behavior.The sample prepared at700 °c by using acetone as the dispersive agent in ball-milling exhibits an excellent rate capability and capacity retention without any fade at 0.1c,1c and 2c,with corresponding average discharge capacities of 153.8,128.3and 121.0 m A·h·g^(-1),respectively,in the first 50 cycles.

关键词： lifepo4/c 材料性能合成条件 X射线粉末衍射扫描电子显微镜正极烧结温度 Li2cO3

Rapid and continuous Production of lifepo4/c Nanoparticles in Super Heated Water

在线全文

学校读者我要写书评

暂无评论

chinese Journal of chemical Engineering 2009年第1期17卷 171-174页

作者：于文利赵亚平饶群力 School of chemistry and chemical Technology Shanghai Jiao Tong University Shanghai 200240 China Instrumental Analysis centre Shanghai Jiao Tong University Shanghai 200240 China

A rapid and continuous method for production of lifepo4/c nanoparticles in super heated water is described,wherein soluble starch was used as carbon precursor.The effects of pH,flow rate,temperature,and pressure on the formation of lifepo4/c particles were investigated.Results showed that the pH value was the key factor on the formation of phase pure lifepo4,which only formed at pH=7;the lifepo4/c occurred as particles with about 70-200 nm size and lifepo4 was covered by a thin carbon layer;higher flow rate,higher pressure,and lower temperature led to smaller particles of lifepo4/c.

关键词：超热水 lifepo4/c 纳米粒子制备方法

Synthetic lifepo4/c without using inert gas

在线全文

学校读者我要写书评

暂无评论

chinese chemical Letters 2007年第3期18卷 337-340页

作者： Guo Rong Hu Xu Guang Gao Zhong Dong Peng Ke Du Yan Jun Liu School of MetaUurgical Science and Engineering Central South University Changsha 410083 China

lifepo4/c was synthesized by high temperature solid-state method with cheap Fe2O3, LiH2PO4 and glucose as raw materials in absence of inert gas. The sample had ordered olivine-type structure other impurities characterized by the test of X-ray diffraction （XRD）. The charge-discharge test showed the sample could demonstrate 120.5 mAh/g at 0.2c rate with good cyclic capability. The powder microeleetrode cyclic voltammetry test indicated that the redox process of the sample had good reversibility.

关键词： Li-ion batty cathode material lifepo4/c Inert gas

不同碳源对多孔球形lifepo4/c复合材料的影响

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2009年第1期25卷 42-46页

作者：于锋张敬杰杨岩峰宋广智中国科学院理化技术研究所北京100190 中国科学院研究生院北京100049

采用喷雾干燥-碳热还原法(SDcTM),分别研究了无机和有机碳源对锂离子正极材料lifepo4/c形貌、结构及其充放电性能的影响。结果表明:以无机碳源炭黑制备的lifepo4/c呈不规则球形,一次颗粒粒径在800nm左右,比表面积为2m2·g-1,0.1c放电比... 详细信息

采用喷雾干燥-碳热还原法(SDcTM),分别研究了无机和有机碳源对锂离子正极材料lifepo4/c形貌、结构及其充放电性能的影响。结果表明:以无机碳源炭黑制备的lifepo4/c呈不规则球形,一次颗粒粒径在800nm左右,比表面积为2m2·g-1,0.1c放电比容量为107.3mAh·g-1。而以有机碳源制备的lifepo4/c,其形貌较为规则,呈多孔球形结构,具有较高的比表面积和放电比容量。其中,以柠檬酸为碳源制备的多孔球形lifepo4/c复合材料,其孔径均在50nm左右,比表面积可达32m2·g-1;在室温下,0.1c和10c首次放电比容量分别为158.8和87.2mAh·g-1,具有优异的循环性能和高倍率充放电性能。

关键词： lifepo4/c 正极材料多孔球形喷雾干燥-碳热还原法(SDcTM)

在线全文

学校读者我要写书评

暂无评论

lifepo4/c制备工艺的优化及其性能

功能材料 2008年第2期39卷 227-230页

作者：赖桂棠李大光李军黄慧民夏信德广东工业大学轻工化工学院广东广州510006 广州市鹏辉电池有限公司博士后工作站广东广州511483

用共沉淀法制备了球形NH4FePO4.H2O前驱体,再与Li2cO3和葡萄糖混合用固相焙烧法制备了lifepo4/c正极材料。利用正交实验考察了焙烧温度、焙烧时间、球磨时间、x(Li)∶x(Fe)和葡萄糖用量等对材料首次放电比容量的影响,得到了最佳工艺条... 详细信息

用共沉淀法制备了球形NH4FePO4.H2O前驱体,再与Li2cO3和葡萄糖混合用固相焙烧法制备了lifepo4/c正极材料。利用正交实验考察了焙烧温度、焙烧时间、球磨时间、x(Li)∶x(Fe)和葡萄糖用量等对材料首次放电比容量的影响,得到了最佳工艺条件。通过XRD、SEM、FTIR和恒流充放电测试仪等测试了材料的结构和电化学性能。所得材料在室温下电流密度为0.1、0.5和1c时首次放电比容量分别为147.6、136.7和122.3mAh/g,循环50次后容量分别为142.8、127.3和106.7mAh/g;在60℃下电流密度为0.5c时,其首次放电比容量为163.8mAh/g,循环性能良好。

关键词： lifepo4/c 正交实验锂离子电池正极材料

水热法制备树叶状lifepo4/c复合正极材料(英文)

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2015年第5期31卷 880-887页

作者：云强周园海春喜申月李翔张丽娟李松丁秀萍中国科学院青海盐湖研究所盐湖资源化学重点实验室西宁810008 中国科学院大学北京100049

采用柠檬酸辅助水热法合成了高分散性树叶状lifepo4/c复合正极材料。利用X射线衍射、傅里叶红外光谱、扫描电镜、高分辨率透射电镜和选区电子衍射分析了材料的形貌结构。结果表明,柠檬酸对树叶状lifepo4/c复合材料的形成具有促进作用。... 详细信息

采用柠檬酸辅助水热法合成了高分散性树叶状lifepo4/c复合正极材料。利用X射线衍射、傅里叶红外光谱、扫描电镜、高分辨率透射电镜和选区电子衍射分析了材料的形貌结构。结果表明,柠檬酸对树叶状lifepo4/c复合材料的形成具有促进作用。该材料的最大暴露晶面为(010)晶面,且分散性较好。与颗粒状lifepo4/c材料相比,该材料呈现出更高的放电比容量和更好的倍率性能,在0.1c和5c倍率下,放电比容量分别为158和126mAh·g-1,其原因是由于锂离子沿[010]方向的扩散距离缩短,从而使锂离子扩散系数显著增大。

关键词：材料科学水热合成电化学 lifepo4/c 树叶状柠檬酸

合成条件对半固相碳热还原法制备lifepo4/c性能的影响

在线全文

学校读者我要写书评

暂无评论

化工新型材料 2010年第8期38卷 37-40页

作者：吴德桥钟本和徐瑞郭孝东刘恒宋杨唐艳四川大学化学工程学院成都610065 四川大学材料科学与工程学院成都610064

以硝酸铁、磷酸锂为原料,聚乙烯醇（PVA）为碳源和还原剂,采用半固相碳热还原法一步合成lifepo4/c,研究了煅烧时间、煅烧温度以及碳含量对材料性能的影响,利用XRD、SEM和恒流充放电等手段研究各个样品的晶型结构、粒度形貌及其电化学性... 详细信息

以硝酸铁、磷酸锂为原料,聚乙烯醇（PVA）为碳源和还原剂,采用半固相碳热还原法一步合成lifepo4/c,研究了煅烧时间、煅烧温度以及碳含量对材料性能的影响,利用XRD、SEM和恒流充放电等手段研究各个样品的晶型结构、粒度形貌及其电化学性能的影响,结果表明：聚乙烯醇过量5%,在烧结温度700℃下维持7h可以得到性能最佳样品,0.1c倍率时放电首次比容量达到152.9mAh.g-1,0.5c倍率放电容量可达138.6mAh.g-1,循环40次后容量维持率97%,具有良好的循环稳定性。

关键词：锂离子电池正极材料 lifepo4/c 合成条件

原位聚合物限制法合成核-壳结构的lifepo4/c纳米复合材料及其热分析动力学研究(英文)

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2012年第S3期41卷 31-34页

作者：李冬云高朋召公伟伟肖汉宁田光磊葛洪良中国计量学院浙江杭州310018 湖南大学湖南长沙410082

以Fecl_36H_2O、NH_4H_2PO_4、cH_3cOOLi等为原料,通过原位聚合物限制法制备出了具有核-壳结构的lifepo4/c纳水材料,利用XRD、HRTEM和TG-DSc等分析测试手段对材料的组成、形貌和热稳定进行表征。结果表明,lifepo_4/c纳米材料是由20~40 n... 详细信息

以Fecl_36H_2O、NH_4H_2PO_4、cH_3cOOLi等为原料,通过原位聚合物限制法制备出了具有核-壳结构的lifepo4/c纳水材料,利用XRD、HRTEM和TG-DSc等分析测试手段对材料的组成、形貌和热稳定进行表征。结果表明,lifepo_4/c纳米材料是由20~40 nm的lifepo4核和1~2 nm的炭壳组成。lifepo_4/c纳米材料的热分解机理为1维随机成核,热分解动力学公式为da/dT=(A/β)exp(-E_a/RT)(1-a),动力学参数为lgA=10.386 min^(-1),E_a=1 38.849 kJ·mol^(-1)

关键词：原位聚合物限制 lifepo4/c 核-壳结构热分解动力学