魏英进
1. 纳米电极材料;2. 核-壳结构型电极材料;3. 电极反应过程动力学。
个性化签名
- 姓名:魏英进
- 目前身份:
- 担任导师情况:
- 学位:
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学术头衔:
博士生导师, 教育部“新世纪优秀人才支持计划”入选者
- 职称:-
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学科领域:
材料科学基础学科
- 研究兴趣:1. 纳米电极材料;2. 核-壳结构型电极材料;3. 电极反应过程动力学。
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20
魏英进, T. Jianga, Y.J. Weib, W.C. Pana, Z. Lia, X. Minga, G. Chenb, C.Z. Wangb, ∗
Journal of Alloys and Compounds 488(2009)L26-L29,-0001,():
-1年11月30日
Li3V2(PO4)3/Cu composite cathode material was prepared via sol-gel method by adding of 1.8 wt% Cu powder into the precursor solution. The structural and physical properties, as well as the electrochemical performance of the material were compared with those of Cu-free Li3V2(PO4)3. X-ray diffraction showed that Cu did not enter the crystal structure of Li3V2(PO4)3. The Li3V2(PO4)3/Cu composite material had a higher electronic conductivity comparing with that of Cu-free Li3V2(PO4)3. Electrochemical impedance spectroscopy showed that the adding of Cu decreased the charge transfer resistance of the electrode. In addition, the lithium diffusion coefficient was prominently enhanced from 1.3×10-9 to 2.8×10-8cm2 s-1. Based on the these advantages, the Li3V2(PO4)3/Cu composite material exhibitedmuch better cycling performance than the Cu-free Li3V2(PO4)3.
Lithium ion battery Cathode material Composite material Electronic conductivity Electrochemical kinetics
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魏英进, Fei Du a, Yingjin Wei a, Yan Chen b, Fang Huc, Xiaofei Bie c, Chunzhong Wang a, Gang Chen a, *, Guangtian Zou a
Solid State Sciences 11(2009)1866-1869,-0001,():
-1年11月30日
The valence state and magnetic properties of hole-doped LiCuVO4 are investigated. By analyzing the Cu 2p core-level photoemission spectra, the holes are suggested to be introduced into Cu2þ site in the formation of Cu3þ ion. The calculation of effective moment also confirms the presence of nonmagnetic Cu3þ ion which should be responsible for the decrease of high-temperature susceptibility after hole doping. At low temperature, the antiferromagnetic transition at 26K and 2.3K disappears due to the enhancement of Curie term. Magnetic hysteresis at 2 K shows that there exists a small ferromagnetic moment of 0.15 emu/g in Li0.9CuVO4.
One-dimensional system Hole dopingCurie term
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【期刊论文】Cluster-spin-glass behavior in layered LiNi0.4Mn0.4Co0.2O2
魏英进, Fei Du, Xiaofei Bie, Yan Chen, Yingjin Wei, Lina Liu, Chunzhong Wang, Guangtian Zou, and Gang Chen, a
JOURNAL OF APPLIED PHYSICS 106, 053904 2009,-0001,():
-1年11月30日
Layered LiNi0.4Mn0.4Co0.2O2 has been synthesized by citrate precursor method. Its magnetic properties are investigated by dc magnetization. The high-temperature susceptibility curve follows the Curie-Weiss law with Curie and Weiss constant 1.435(2) emu K/mol Oe and -112(4) K, respectively, larger than those values reported in previous researches, which possibly results from the difference in the synthesis process and sintered temperature. Our dc susceptibility differs from that of the homogeneous spin glass in that below Tirr field cooled (FC) curve continues to rise, while the FC curve is almost flat for homogeneous spin glass. Together with the de Almeida-Thouless line analysis, cluster spin glass is suggested to be the ground state of LiNi0.4Mn0.4Co0.2O2. Frustration parameter |Ø| /Tf in this system is estimated to be about four, lower than the value that frustration effect is strong enough to give rise to spin glass state. This fact indicates that the cluster-spin-glass results from the short-range structure disorder rather than the geometrical frustration.
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【期刊论文】新型锂离子电池正极材料Li0.86V0.8O2的水热合成及性质
魏英进, 胡方, 杜菲, 陈岩, 明星, 陈岗, 王春忠
高等学校化学学报,2009,30(8):1492~1496,-0001,():
-1年11月30日
采用两步反应制备了新型锂离子电池正极材料Li0.86V0.8O2.该材料具有六方层状结构,空间群为R3m.研究了在水热条件下溶液的碱度对于钒酸锂盐形成的影响,在低碱度的条件下,前驱体V2O3和LiOH·H2O并未发生反应,只有在碱度达到215mol/L时,才能形成单相的Li0.86V0.8O2材料.X射线光电子能谱分析发现,V2p的结合能位于516.4和523.1eV,分别对应于四价钒离子的V2p3/2和V2p1/2,这说明在Li0.86V0.8O2中V离子主要价位为+4价.在电流密度为714mA/g的充放电中,Li0.86V0.8O2初始充电容量达到163mA·h/g,首次放电容量也能达到113mA·h/g,20次循环后放电容量仍然可以达到80mA·h/g,表现出较好的循环性能.
锂离子电池, 正极材料, 水热合成法, L i0., 86V0., 8O2, X射线光电子能谱
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魏英进, Y.J. Wei a, *, K. Nikolowski b, S.Y. Zhan a, H. Ehrenberg b, S. Oswald b, G. Chen a, C.Z. Wanga, H. Chen a
Electrochemistry Communications 11(2009)2008-2011,-0001,():
-1年11月30日
Li[Li0.23Co0.3Mn0.47]O2 cathode material was prepared by a sol-gel method. The material had a primary particle size of about 100 nm, covered by a 30 Å of Li2CO3 layer. The material showed promising electrochemical performance when cycled up to 3C rate. The electrochemical kinetics of the first charge was much slower than that of the second charge, due to the complex electrochemical process which involved not only Li+ diffusion but also release of oxygen. By taking account of this, the material was pre-charged very slowly (~C/50) in the first cycle. This led to excellent electrochemical performance in the following cycles. For instance, the 1C-rate capacity increased to 168 mAhg-1 after 50 cycles, comparing with the 145 mAhg-1 obtained without pre-charging.
Lithium ion battery Cathode material Nano material Electrochemical kinetics Cycling performance
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魏英进, Jiajia Ning, †, ‡ Tao Jiang, ‡ Kangkang Men, † Quanqin Dai, † Dongmei Li, † Yingjin Wei, *, ‡ Bingbing Liu, † Gang Chen, ‡ Bo Zou, † and Guangtian Zou†
J. Phys. Chem. C 14140 2009, 113, 14140-14144,-0001,():
-1年11月30日
Hierarchical SnO nanocrystals are synthesized by a reproducible and facile way via decomposition of an intermediate product tin oxide hydroxide, Sn6O4(OH)4. By changing the amount of injecting water, layerplate-like, nest-like, stepwise-bipyramid-like, and defective stepwise-bipyramid-like hierarchical SnO nanocrystals could be obtained. All of these hierarchical SnO nanostructures are constructed by smaller nanosheets. The driving force of aggregation is reducing the surface energy of nanocrystals. Water played a key role in the control morphologies of hierarchical SnO nanostructures. The water control decomposition (WCD) mechanism was proposed to explain the effect of water on the morphologies. On the basis of reaction kinetics, the different superfluous injected water after reaction would restrain the decomposition of Sn6O4(OH)4 to SnO nanosheets; a different amount of superfluous injected water would induce a different reaction rate. At different reaction rates, SnO nanosheets would have different sizes and different approaches to aggregation, and different hierarchical SnO nanocrystals appeared by injecting different amounts of water into the reaction. Typically, hierarchical SnO nanocrystals as an anode material for lithium ion batteries are studied. These SnO nanocrystals show good potential for lithium battery materials. Among these SnO nanostructures, the stepwise-bipyramid-like nanostructure shows the best properties.
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【期刊论文】Electrochemical properties of Cr doped V2O5 between 3.8 V and 2.0 V
魏英进, S.Y. Zhan a, C.Z. Wang a, K. Nikolowski b, H. Ehrenberg b, G. Chen a, Y.J. Wei a, *
Solid State Ionics 180(2009)1198-1203,-0001,():
-1年11月30日
Cr0.1V2O5.15 was prepared by an oxalic acid assisted sol-gel method. X-ray diffraction showed that Cr doping induced a slight expansion (ΔV/V≈2.3%) in the crystal lattice of V2O5. The electrochemical properties of Cr0.1V2O5.15 in the potential range of 3.8-2.0 V were studied by cyclic voltammetry, galvanostatic charge- discharge cycling and potentiostatic intermittent titration technique. Cyclic voltammetry showed that the irreversible phase transition of V2O5 during the first cycle was effectively prevented by Cr doping. This caused the good charge-discharge cycling performance of the doped material. The discharge capacities were recorded to be 200, 170 and 120 mAhg-1 after fifty cycles at the C/10, C/2 and 1C rates, respectively. However, ex-situ X-ray diffraction showed that the crystal structure of the material was destroyed after longterm cycling. The lithium diffusion coefficient of Cr0.1V2O5.15 varied between 10-11 and 10-12 cm2 s-1, which was larger than that of crystalline V2O5, and was close to those of metal doped V2O5 in previous reports. The improvement in lithium diffusion kinetics was regarded as an important reason for the good electrochemical performance of Cr0.1V2O5.15.
Lithium battery Vanadium pentoxide Charge-discharge cycling Cyclic voltammetry Potentiostatic intermittent titration technique
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魏英进, Tao Jiang a, Chunzhong Wang a, Gang Chen a, Hong Chen a, b, Yingjin Wei a, *, Xu Li a
Solid State Ionics 180(2009)708-714,-0001,():
-1年11月30日
A series of monoclinic Li3V2(PO4)3 cathode materialswere prepared by H2 reduction (LVP-H2) and carbothermal reduction (LVP-CTR) methods. LVP-H2 showed a primary particle size of about 1μm,whichwasmuch larger than the LVP-CTR samples. A uniform surface carbon layer was observed for the LVP-CTR samples by transmission electron microscope. This carbon layer not only limited the particle growth of the materials but also enhanced the material's electronic conductivity by five orders of magnitude. The LVP-CTR samples exhibited much better electrochemical performance than LVP-H2. The good electrochemical performance of LVP-CTR was attributed to its nano particle size, high electronic conductivity, aswell as the surface carbon layerwhich limited the vanadium dissolution in electrolyte.
Lithium ion battery Cathode material Lithium vanadium phosphate Electronic conductivity Electrochemical properties
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【期刊论文】梯形化合物NaV2O4F电子结构的第一性原理研究*
魏英进, 胡方), 明星), 范厚刚)), 陈岗), 王春忠), 魏英进), 黄祖飞))+
物理学报,2009,58(2):1173~1178,-0001,():
-1年11月30日
采用基于密度泛函理论(DFT)的第一性原理赝势平面波方法,通过自旋极化的广义梯度近似(GGA)电子结构计算对梯形化合物NaV2O4F进行了研究。考虑了四种假想的自旋有序态,计算结果表明该化合物的磁基态具有二维反铁磁(AFM)结构,即沿梯阶和梯腿方向都表现为AFM作用。能带结构显NaV2O4F为绝缘体材料,带隙约为110eV。方锥体中的晶体场劈裂使得VO4F方锥体中的V4+(3d1)离子的未配对电子填充dxy轨道。电负性极强的F离子使得梯阶上的共价性减弱,并导致梯阶上的交换作用减弱。采用Noodleman的对称性破缺方法由Ising模型拟合出的自旋交换耦合常数表明NaV2O4F的梯间还存在强度与梯阶的AFM作用相当的铁磁(FM)相互作用,说明该梯形化合物很可能不是一种自旋梯材料。
NaV2O4F,, 梯形化合物,, 第一性原理计算,, 电子结构
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【期刊论文】Characterizations on the structural and electronic properties of thermal lithiated Li0.33MnO2
魏英进, Y.J.Wei a, H. Ehrenbergb, K.B. Kimc, ∗, C.W. Parkd, Z.F. Huanga, C. Baehtze
Journal of Alloys and Compounds 470(2009)273-277,-0001,():
-1年11月30日
A 3V cathode material for lithium ion batteries, Li0.33MnO2, was synthesized by solid-state reaction. Two Mn crystallographic positions, Mn(1) and Mn(2), were determined by X-ray diffraction analysis. The [Mn(2)O6] octahedron had a lower symmetrical degree than that of [Mn(1)O6], which was attributed to the geometrical effects of the non-symmetrical environment around Mn(2). Li0.33MnO2 delivered a reversible discharge capacity ~140mAhg-1. In situ synchrotron diffraction clearly showed a reversible phase transition of Li0.33MnO2 during electrochemical process. The analysis of X-ray absorption near edge spectroscopy observed the conversion of Mn4+ to Mn3+ with Li+ intercalation into Li0.33MnO2, accompanied by the formation of more severely distorted [MnO6] octahedron.
Lithium battery Electrode materials Crystal structure Electronic property
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