检索结果-南通市图书馆

Co^3+-modified Surface of limn2o4 Spinel for its Improvement of Electrochemical Properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2003年第4期19卷 359-362页

作者： ZishanZHENG ZilongTANG ZhongtaiZHANG JunbiaoLU WanciSHEN DepartmentofChemistry ZhangzhouTeachersCollegeZhangzhou363000PujianChina StateKeyLaboratoryofNewCeramicsandFineProcessing DepartmentofMaterialsScienceandEngineering.TsinghuaUniversityBeijing100084China

Cobalt was used to modify the surface of spinel limn2o4 by a solution technique to produce Co3+-modified surface material (CoMSM). Cobalt was only doped into the surface of limn2o4 spinel. XPS(X-ray photoelectron spectroscopy) analysis confirms the valence state of Co3+. CoMSM has stable spinel structure and can prevent active materials from the corrosion of electrolyte. The ICP(inductively coupled plasma) determination of the spinel dissolution in electrolyte showed the content of Mn dissolved from CoMSM was smaller than that from the pure spinel. AC impedance patterns show that the charge-transfer resistance (Ret) for CoMSM is smaller than that for pure spinel. The particles of CoMSM are bigger in size than those of pure spinel according to the micrographs of SEM(scanning electron microscopy). The determinations of the electrochemical characterization show that CoMSM has both good cycling performance and high initial capacity of 124.1 mA/h at an average capacity loss of 0.19 mAh/g per cycle.

关键词： Lithium ion batteries limn2o4 Cation doping Coating

Characteristics of LiCoo2, limn2o4 and LiNi0.45Co0.1Mn0.45o2 as cathodes of lithium ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University of Technology 2005年第z1期12卷 44-49页

作者： GUo Hua-jun LI Xin-hai ZHANG Xin-ming ZENG Su-ming WANG Zhi-xing PENG Wen-jie School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China

LiNi0. 45 Co0. 10 Mn0. 4so2 was synthesized from Li2Co3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 o2, LiCoo2 and limn2 o4 were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi0.4s Co0.10 Mn0. 45 o2 has a layered structure with hexagonal lattice. The commercial Licoo2 has sphere-like appearance and smooth surfaces, while the limn2 o4 and LiNi0.45 Co0. 10 Mn0. 45 o2 consist of cornered and uneven particles. LiNi0. 45 Co0.10 Mn0. 45 o2 has a large dislimn2 o4 and LiCoo2, respectively. LiCoo2 and limn2 o4 have higher discharge voltage and better rate-capability than LiNi0. 45Co0.10 Mn0. 45 o2. All the three cathodes have excellent cycling performance with capacity retention of above 89.3 % at the 250th cycle. Batteries with limn2 o4 or LiNi0.45 Co0.10 Mn0. 45 o2 cathodes show better safety performance under abusive conditions than those with LiCoo2 cathodes.

关键词： lithium ion batteries cathode LiCoo2 limn2o4 LiNi0. 45 Co0. 10 Mn0. 45 o2

Influence on performance and structure of spinel limn2o4 for lithium-ion batteries by doping rare-earth Sm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University of Technology 2005年第z1期12卷 28-32页

作者： PENG Zhong-dong HU Guo-rong LIU Ye-xiang School of Metallurgy Science and Engineering Central South University Changsha 410083 China School of Metallurgy Science and Engineering Central South University Changsha 410083 China School of Metallurgy Science and Engineering Central South University Changsha 410083 China

The spinel limn2o4 used as cathode materials for lithium-ion batteries was synthesized by mechanochemistry fluid activation process, and modified by doping rare-earth Sm. Testing of X-ray diffraction, cyclic voltammograms, charge-discharge and SEM was carried out for limn2o4 cathode materials and the modified *** results show that the cathode materials doped rare earth LixMn2-ySmxo4 (0.95≤x≤1.2, 0≤y≤0.3, 0≤z≤0.2) exhibit standard spinel structure, high reversibility of electrochemistry and excellent properties of charge-discapacity is deteriorated less than 15% after 300 cycles at room temperature and less than 20% after 200 cycles at 55 *** the same time, Crystal Field Theory was applied to explain the function and mechanism of doped rare earth element.

关键词： lithium-ion batteries Sm cathode material rare-earth limn2o4

Determination of Li+ solid diffusion coefficient in limn2o4 by CITT

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University of Technology 2005年第z1期12卷 1-4页

作者： TANG Xin-cun HUANG Bai-yun HE Yue-hui School of Chemistry and Chemical Engineering Central South University Changsha 410083 China State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China

The capacity intermittent titration technique (CITT) was developed based on the ratio of potentio-charge capacity to galvano-charge capacity (RPG) method, to continuously determine the solid diffusion coefficient (D) of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs the value of ratio of the potentio-charge capacity to the galvano-charge capacity (q) were given. By the CITT technique,the Li+ solid diffusion coefficients within limn2 o4 at different voltages were determined. The results show that the values of D varied from 3. 447× 10-9 to 7.60× 10-11 cm2/s in the voltage range of charge from 3.3 to 4.3 V as a function of voltage with "W" shape.

关键词： capacity titration technique Li+ solid diffusion coefficient limn2o4

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

limn2o4空心多孔正极材料的制备

过程工程学报 2018年第1期18卷 190-195页

作者：钱兵宋修梅岳军伟刘青青孙雅馨安徽工业大学材料科学与工程学院安徽马鞍山243002 燕山大学亚稳材料制备技术与科学国家重点实验室河北秦皇岛066004

以水热法所制碳球为模板,采用溶胶-凝胶法制备limn2o4空心多孔颗粒（PLMo）,研究了煅烧温度和碳球加入量对样品相演化和表面形貌的影响,比较了PLMo和未加入碳球的limn2o4（LMo）的电化学性能.结果表明,650750℃煅烧12h可制得蜂窝状孔型... 详细信息

以水热法所制碳球为模板,采用溶胶-凝胶法制备limn2o4空心多孔颗粒（PLMo）,研究了煅烧温度和碳球加入量对样品相演化和表面形貌的影响,比较了PLMo和未加入碳球的limn2o4（LMo）的电化学性能.结果表明,650750℃煅烧12h可制得蜂窝状孔型结构的PLMo;在放电倍率0.5C下循环50次,PLMo的放电容量从126mA×h/g降至111mA×h/g,均高于相应LMo的放电容量.在5C放电倍率下,PLMo的首次放电容量可达89mA×h/g,较LMo提高约39%.

关键词： limn2o4 空心多孔材料碳球溶胶-凝胶法

熔融盐法制备limn2o4材料的合成条件研究

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2008年第4期24卷 615-620页

作者：杜柯杨亚男胡国荣彭忠东其鲁中南大学冶金科学与工程学院轻金属与工业电化学研究所长沙410083 北京大学化学与分子工程学院应用化学系新能源与技术实验室北京100871

采用熔融盐法制备锂离子电池正极材料limn2o4,对制备过程中熔融盐种类、焙烧时间和焙烧温度等影响因素进行了系统研究。通过XRD、SEM和充放电测试,研究了产物的组成结构、形貌及电化学性能。研究结果表明,合成的limn2o4样品具有完整的... 详细信息

采用熔融盐法制备锂离子电池正极材料limn2o4,对制备过程中熔融盐种类、焙烧时间和焙烧温度等影响因素进行了系统研究。通过XRD、SEM和充放电测试,研究了产物的组成结构、形貌及电化学性能。研究结果表明,合成的limn2o4样品具有完整的尖晶石结构;样品的粒径分布范围小,平均粒径为几百纳米;优化实验条件之后制备得到的材料,在电压范围3.3～4.3V,充放电电流值为60mA.g-1(0.5C)时,初始放电比容量约125mAh·g-1,最初50次0.5C充放电循环的比容量保持率约为95%,在后续50次1C循环中,比容量保持率为96%左右,循环性能优良。

关键词：锂离子电池 limn2o4 熔融盐法正极材料

锂离子电池镍掺杂尖晶石limn2o4正极材料的电子结构

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2008年第10期24卷 1576-1581页

作者：伊廷锋朱彦荣诸荣孙胡信国安徽工业大学化学与化工学院马鞍山243002 哈尔滨工业大学应用化学系哈尔滨150001

采用密度泛函平面波赝势方法对limn2o4和LiNi0.5Mn1.5o4的几何结构进行了优化,并计算了相应的电子结构。计算的结果表明:在Li+脱嵌前后,limn2o4和LiNi0.5Mn1.5o4均为导体,且锂元素主要以离子形式存在于两种材料中,o2p轨道与Mn(Ni)的3d... 详细信息

采用密度泛函平面波赝势方法对limn2o4和LiNi0.5Mn1.5o4的几何结构进行了优化,并计算了相应的电子结构。计算的结果表明:在Li+脱嵌前后,limn2o4和LiNi0.5Mn1.5o4均为导体,且锂元素主要以离子形式存在于两种材料中,o2p轨道与Mn(Ni)的3d轨道形成了较强的共价键。Li+嵌入导致Mn(Ni)3d轨道的态密度峰发生移动。Ni的掺杂导致Mn(Ni)和o2p轨道的成键作用得以加强,电子在Mn(Ni)3d轨道的填充发生变化,从而提高了电池的充放电电压。

关键词：正极材料尖晶石 limn2o4 LiNi0.5Mn1.5o4 电子结构密度泛函理论

导电氧化物AZo对尖晶石型limn2o4高温性能的改善及研究

在线全文

学校读者我要写书评

暂无评论

无机化学学报 2014年第4期30卷 725-732页

作者：夏丙波仇光超孙洪丹方国清刘伟伟张瑞雪王宏宇李德成苏州大学化学电源研究所江苏省锂电池材料重点实验室苏州215006 常州储能材料与器件研究院常州213003

采用溶胶凝胶法对尖晶石型limn2o4正极材料进行铝掺杂氧化锌(AZo)包覆改性,并通过XRD、SEM、EDS、TEM、EIS、ICP-AES和充放电测试等手段对其结构,形貌及电化学性能进行表征。研究结果表明,AZo包覆层有效的阻止了limn2o4颗粒和电解液的... 详细信息

采用溶胶凝胶法对尖晶石型limn2o4正极材料进行铝掺杂氧化锌(AZo)包覆改性,并通过XRD、SEM、EDS、TEM、EIS、ICP-AES和充放电测试等手段对其结构,形貌及电化学性能进行表征。研究结果表明,AZo包覆层有效的阻止了limn2o4颗粒和电解液的直接接触,抑制了高温下锰溶解,明显改善了limn2o4的高温循环性能。1.5wt%AZo包覆的limn2o4正极材料在高温(55℃)1C时,首次放电比容量为114 mAh·g-1,经过100次循环后,容量保持率仍高达95.4%,远高于未包覆limn2o4的70.6%。此外,1.5wt%AZo包覆的limn2o4表现出了优越的大倍率放电性能,在10C下放电比容量能达到99 mAh·g-1。

关键词：锂离子电池正极材料溶胶凝胶法 limn2o4 锰溶解导电AZo 包覆

limn2o4 with hierarchical porous morphology obtain an excellent electrochemical performance

在线全文

学校读者我要写书评

暂无评论

LiMn2O4 with hierarchical porous morphology obtain an excell...