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Rare Metals 2007年第4期26卷 330-334页

作者： YI Tingfeng WANG Dianlong GAO Kun HU Xinguo Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China School of Chemistry and Chemical Engineering Anhui University of Technology Maanshan 243002 China

An Al-doped spinel lithium manganese oxide was prepared by the adipic acid-assisted sol-gel method at 800℃, and the cathode materials （Liml0.05Mnl.9504） with different particle sizes were obtained through ball milling. The effects of particle size on the electrochemical performance of LiAl0.05Mnl.9504 samples were investigated by differential thermal analysis and thermogravimetry, X-ray diffraction, galvanostatic charge-discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy. The results indicate that all samples with different particle sizes show the same pure spinel phase and good crystal structure; ***.9504 with Dso = 17.3 μm shows better capacity retention; ***4 cathode materials with small particle size have a bigger resistance of charge transfer than the large one, and the particle size has significant effects on the electrochemical performance of Al-doped spinel LiMn2O4 cathode materials.

关键词： lithium ion battery LiAl0.05Mn1.95O4 electrochemical properties particle size

Effects of Fe-substitution for cobalt on electrochemical properties of La-Mg-Ni-based alloys

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Journal of Rare Earths 2010年第2期28卷 290-294页

作者：蒿建生韩树民李媛扈琳张静武 State Key Laboratory of Metastable Materials Science and Technology Yanshan University Department of Environmental and Chemical Engineering Yanshan University

In order to improve electrochemical properties,especially cycling stability,Co was partially substituted by Fe in A2B7-type La-Mg-Ni-based *** La0.74Mg0.26Ni2.55Co0.65-xFex(x=0,0.10,0.20,0.30) alloys were prepared by inductive melting,and their phase structure and electrochemical properties were *** XRD and SEM results showed that the alloys consisted mainly of(La,Mg)2Ni7 phase,(La,Mg)5Ni19 phase and LaNi5 phase,except for absence of LaNi5 phase in the non-substituted ***(La,Mg)5Ni19 ph...

关键词： hydrogen storage alloys elemental substitution electrochemical properties phase structure rare earths

Effect of modified elastomeric binders on the electrochemical properties of silicon anodes for lithium-ion batteries

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 752-756页

作者： Tao Li Juan-yu Yang Shi-gang Lu General Research Institute for Nonferrous Metals Beijing 100088China

Silicon has been investigated intensively as a promising anode material for rechargeable lithium-ion batteries. The choice of a binder is very important to solve the problem of the large capacity fade observed along cycling. The effect of modified elastomeric binders on the electrochemical performance of crystalline nano-silicon powders was studied. Compared with the conventional binder （polyvinylidene fluoride （PVDF））, Si electrodes using the elastomeric styrene butadiene rubber （SBR） and sodium carboxymethyl cellulose （SCMC） com- bined binder show an improved cycling performance. The reversible capacity of the Si electrode with the SCMC/SBR binder is as high as 2221 mA.h/g for 30 cycles in a voltage window between 0.005 and 2 V. The structure changes from SEM images of the silicon electrodes with different binders were used to explore the property improvement.

关键词： lithium batteries silicon anodes electrochemical properties

Microstructure and electrochemical properties of LaNi_(4-x)FeMn_x (x=0-0.8) hydrogen storage alloys

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Journal of Rare Earths 2009年第5期27卷 853-857页

作者：羊恒陈云贵陶明大吴朝玲 College of Materials Science and Engineering Sichuan University

In order to reduce the cost of LaNi5 based hydrogen storage alloys, effect of substitution of Mn for Ni on structural and electrochemical properties of LaNi4-xFeMnx (x=0-0.8) hydrogen storage alloys was studied systematically. X-ray diffraction (XRD) and scanning electron microscope (SEM) showed that LaNi5 and La2Ni7 phases were invariably present in all alloy samples, and when x >= 0.4, (Fe, Ni) phase was observed. electrochemical studies revealed that the discharge capacity reached a maximum value of 306.4 mAh/g when x=0.2 and the cycling stability decreased with the increase of x. With the increase of Mn content, hydrogen diffusion coefficient decreased, whereas high rate discharge-ability (HRD) and exchange current density first increased slowly when x electrochemical reaction on the surface of alloy electrodes had strong influence on kinetic property.

关键词： hydrogen storage materials electrochemical properties Co-free AB(5)-type alloy rare earths

Structure and electrochemical properties of hypo-stoichiometric hydro-gen storage alloys prepared by twin-roller rapid quenching process

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Rare Metals 2005年第4期24卷 336-340页

作者： ZHOU Liu LU Dongsheng LI Weishan HU Shejun CAI Yuepeng TANG Renheng XIAO Fangming Department of Chemistry South China Normal University Guangzhou 510631 China Guangzhou Institute of Nonferrous Metal Research Guangzhou 5100013 China

The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.

关键词： hydrogen storage alloys structure electrochemical properties XRD electrochemical methods stoichiometry twin-roller rapid quenching process

Microstructures and electrochemical properties of LaNi_(3.8-x)Al_x hydrogen storage alloys

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Journal of Rare Earths 2013年第5期31卷 497-501页

作者：王伟陈云贵李强杨维才 China Academy of Engineering Physics College of Materials Science and Engineering Sichuan University

The microstructttres and electrochemical properties of LaNi3.8-xAlx （x=0.0, 0.1, 0.2, 0.3 and 0.4） alloys were studied sys- tematically. The microstructures were identified by X-ray diffraction （XRD） and scanning electronic microscopy （SEM）. The main phases were not changed with the substitution of Ni by A1, but minor phases appeared when x=0.4. With A1 content increasing, the cell volume increased and the hydrogen storage capacity increased first and then decreased, and the maximum discharge capacity increased fi：om 209.4 mAh/g （x=0.0） to 285.3 mAh/g （x=0.3） and then decreased to 241.3 mAh/g （x=0.4）. Meanwhile, the exchange current density （10） increased and the diffusion coefficient （D） decreased with the addition of Al.

关键词： hydrogen storage alloy La5Ni19 electrochemical properties rare earths

Synthesis and electrochemical properties of Li_2MnSiO_4/C nanoparticles via polyol process

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Rare Metals 2010年第5期29卷 511-514页

作者： LIU Wengang XU Yunhua YANG Rong School of Material Science and Engineering Xi 'an University of Architecture and Technology Xi 'an 710055 China School of Science Xi 'an University of Technology Xi 'an 710048 China

Carbon-coated lithium manganese silicate （Li2MnSiO4/C） nanoparticles were synthesized by polyol process. X-ray diffraction （XRD） patterns of the obtained materials exhibit a good fit with that of the Li2MnSiO4 phase. Field emission scanning electron microscopy （FESEM） images of the obtained samples show that the particle size is only tens of nanometers. The high resolution transmission electron microscopy （HRTEM） analysis shows that the Li2MnSiO4 nanoparticles are surrounded by a very thin film of amorphous carbon. The composite prepared through polyol process shows good performance as cathode materials in lithium cells at room temperature. The charge capacity of the Li2MnSiO4/C samples is 219 mAh/g （about 1.3 Li^＋ per unit formula extracted）, and the discharge capacity is 132 mAh/g （about 0.8 Li^＋ per unit formula inserted） in the first cycle in the voltage range of 1.5-4.8 V. A good capacity cycling maintenance of 81.8% after 10 cycles was obtained.

关键词： lithium ion batteries cathode materials electrochemical properties polyol process silicates

Effect of the synthesis method of SnSb anode materials on their electrochemical properties

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Journal of University of Science and Technology Beijing 2007年第4期14卷 345-349页

作者： Chaoli Yin Hailei Zhao Hong Guo Xianliang Huang Weihua Qiu Department of Inorganic Nonmetallic Materials University of Science and Technology Beijing Beijing 100083 China

SnSb alloy powders for the anode of Li-ion batteries were synthesized by two kinds of reduction precipitation methods： solution titration and rapid mixing. Two kinds of SnSb alloy powders showed different phase compositions and particle morphologies although the same starting materials were used. The SnSb alloy electrode synthesized by titration exhibits high reversible specific capacity and good cycling stability, whereas the rapid-mixing sample shows high irreversible capacity and fast capacity fade. The broad particle size distribution of SnSb powders synthesized by titration is considered to be responsible for the improvement of cycling stability. The initial charge-discharge efficiency exceeding 80% has been obtained for the titration sample. The electrochemical reaction process of two kinds of synthesized SnSb composite electrodes was characterized by cyclic voltammetry and AC impedance techniques.

关键词： SnSb alloys lithium-ion batteries anode electrochemical properties

Effect of commercial AB_5 alloy addition on the electrochemical properties of Ml-Mg-Ni-based hydrogen storage alloys

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Rare Metals 2008年第4期27卷 429-433页

作者： HU Lin HAN Shumin LI Jinhua ZHU Xilin LI Yuan State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China College of Environmentaland Chemical Engineering Yanshan University Qinhuangdao 066004 China

A commercial AB5 hydrogen storage alloy was used as an additive to improve the electrochemical properties of Ml-Mg-Ni-based hydrogen storage alloys. The effect of AB5 alloy addition on the phase structure, charge/discharge characteristics, and electrochemical kinetics of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 alloy was investigated. The maximum discharge capacity of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 ＋ 4 wt.% AB5 electrode reaches 406 mAh/g. The anodic polarization, cyclic voltammetry, and potential step discharge experiments show that the electrochemical kinetics of the electrode with additives was promoted, with the LaNi5 phase of AB5 alloy acting as electro-catalytic sites in the electrode alloy. The high-rate dischargeability of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 ＋ 4 wt.% AB5 alloy electrode at 1100 mA/g reaches 60.9%, which is 9.4% higher than that of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 alloy electrode. The cycling stability of the electrode with 4 wt.% AB5 alloy has also been improved

关键词： hydrogen storage alloys additive rare earths electrochemical properties electrochemical kinetics

Effects of annealing on microstructures and electrochemical properties of La_(0.8)Mg_(0.2)Ni_(2.4)Mn_(0.10)Co_(0.55)Al_(0.10) alloy

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Journal of Rare Earths 2008年第3期26卷 398-401页

作者：宋大卫王一菁刘毅韩树民焦丽芳袁华堂 Institute of New Energy Material Chemistry Nankai University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

The La0.8Mg0.2Ni2.4Mn0.10Co0.55Al0.10 alloy was prepared by induction melting. The structural and morphological characterizations were performed by means of X-ray powder diffraction （XRD） and scanning electron microscopy （SEM）. The electrochemical measurements were performed using LAND and CH/660b electrochemical workstation. The main phases of the alloy were LaNi5 and （La,Mg）Ni3. After annealing, the maximum discharge capacity, cycle stability and high rate dischargeability （HRD） were improved obviously. The maximum discharge capacity reached 373.80 mAh/g （T=1173 K）, the C100/Cmax（%） was 72.63% （T=1173 K）, and the value of HRD reached 51.8% at a discharge current density of 1150 mA/g （T=1173 K）. The cyclic voltammetry （CV） and potentiodynamic polarization were also studied.

关键词： hydrogen storage alloys phase structure electrochemical properties metal hydrides almealing treatment rare earths