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31.
磷酸铁(FePO4)是锂电池正极材料磷酸铁锂(LiFePO4)的核心前驱体,FePO4形貌及硫含量对合成的LiFePO4材料性能有重要影响。为得到类球形低硫FePO4产品,在传统液相沉淀法技术基础上做了改进优化,添加十六烷基三甲基溴化铵(CTAB)作为形貌助剂提高产品球形度,添加氨水作为配体形成磷酸铁铵配合物改善结晶过程,降低产品硫含量。结果表明:所制备的FePO4产品硫质量分数低,达到2.6×10 -5,形貌为均一的微米类球形颗粒,D50=11.4 μm,振实密度达到1.22 g/cm 3,有望成为制备高压实密度LiFePO4材料的核心前驱体。 相似文献
32.
Aqueous photoresists that are capable of higher resolutions than are currently employed by the cathode ray tube (CRT) industry were developed by combining photoactivators, which activate at shorter UV wavelengths with polyvinylpyrrolidone (PVP). Two photoactivators were synthesized: 4,4′‐diazido‐2,2′‐biphenyl disodium disulfonate (DABP), which has a maximum absorbance at 264 nm, and 4,4′‐diazido‐2,2′‐biphenylethane disodium disulfonate (DABPE), which has a maximum absorbance at 258 nm. The PVP/DABP and PVP/DABPE photoresists successfully imaged a pattern with resolution as small as 4.4 μm with photoactivator concentrations greater than 20% of the PVP concentration. Addition of silane and emulgen greatly improved the performance of the photoresists with more uniform coatings of thicknesses of up to 1.4 μm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1637–1644, 2006 相似文献
33.
This work provides kinetic and transport parameters of Li-ion during its extraction/insertion into thin film LiNi0.5Mn1.5O4 free of binder and conductive additive. Thin films of LiNi0.5Mn1.5O4 (0.2 μm thick) were prepared on electronically conductive gold substrate utilizing the electrostatic spray deposition technique. High purity LiNi0.5Mn1.5O4 thin film electrodes were observed with cyclic voltammetry, to exhibit very sharp peaks, high reversibility, and absence of the 4 V signal related to the Mn3+/Mn4+ redox couple. The electrode subjected to 100 CV cycles of charge/discharge delivered a capacity of 155 mAh g−1 on the first cycle and sustained a good cycling behavior while retaining 91% of the initial capacity after 50 cycles. Kinetics and mass-transport of Li-ion extraction at LiNi0.5Mn1.5O4 thin film electrode were investigated by means of electrochemical impedance spectroscopy. The apparent chemical diffusion coefficient (Dapp) value determined from EIS measurements changed depending on the electrode potential in the range of 10−10-10−12 cm2 s−1. The Dapp profile shows two minimums at the potential values close to the peak potentials of the corresponding cyclic voltammogram. 相似文献
34.
Layered Li[Li0.12NizMg0.32−zMn0.56]O2 oxide cathodes containing lithium atoms in the transition metal layers were synthesized and characterized using X-ray diffraction (XRD), galvanostatic cycling, and differential scanning calorimetry (DSC). The Li[Li0.12NizMg0.32−zMn0.56]O2 cathodes deliver a specific discharge capacity of about 190 mAh/g at room temperature and 236 mAh/g at 55 °C when cycled between 2.7 and 4.6 V versus Li/Li+. Excellent capacity retention and smooth potential profiles at room and elevated temperatures over extended cycles suggest that this material does not convert into a spinel structure. 相似文献
35.
36.
A method for producing electrocatalysts containing silver supported on different carbons was developed. The catalysts were investigated in air (oxygen) diffusion electrodes in alkaline electrolyte (7 M KOH). Depending on the carbon support used, up to a threefold improvement in electrode performance was achieved compared with the activity of the uncatalysed carbon in this media. At ambient temperature and atmospheric pressure, a current density of 150 mA/cm–2 was obtained at electrode potential 1.2 V vs zinc (0.75 vs HE). A correlation between electro catalytic activity and wetted surface area of the electrocatalysts was found. 相似文献
37.
38.
中温固体氧化物燃料电池的研制是固体氧化物燃料电池商业圈的必然趋势,影响其发展的关键问题之一就是阴极材料的研制。钙钛矿结构稀土复合氧化物材料是最有前途的中低温固体氧化物燃料电池阴极材料。本文对钙钛矿结构含镧复合氧化物的电催化机理进行详尽的叙述,并提出了其发展方向。 相似文献
39.
E. A. Levashov A. S. Rogachev V. V. Kurbatkina Yu. K. Epishko N. A. Kochetov 《International Journal of Self-Propagating High-Temperature Synthesis》2007,16(4):218-224
Biocompatible composites (Ti, Ta)C
x
+ Ca3(PO4)2 for deposition of nanofilms onto load-bearing implants by ion-plasma sputtering were prepared from Ti + Ta + C + Ca3(PO4)2 mixtures by forced SHS compaction. The effect of Ta + C addition to green mixtures (characterized by parameter z) on the structure/phase formation in combustion products was explored. The addition of tantalum and carbon was found to have
little or no influence on the burning velocity U and combustion temperature T
c. Two thermal spikes exhibited by thermograms were associated with the occurrence of two consecutive reactions leading to
formation of titanium and tantalum carbides. With increasing z, the grain size of (Ti, Ta)C was found to diminish, its relative density to decrease, while the hardness to markedly grow.
相似文献
40.
Dong Shu Jinghua Zhang Chun He Yuezhong Meng Hongyu Chen Yongsheng Zhang Mianping Zheng 《Journal of Applied Electrochemistry》2006,36(12):1427-1431
High electrocatalytic activity of an electropolymerized film of poly(3-methoxythiophene) (PMOT) is reported toward the redox reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) as a promising cathode material for the lithium ion battery. Cyclic voltammetry showed improved electrochemical performance of DMcT on PMOT-coated Pt electrode, indicating accelerated redox kinetics. Moreover, charge-discharge tests exhibited higher discharge capacity and slower capacity fading of the PMOT-doped DMcT composite cathode compared with pure DMcT. 相似文献