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钒电池是一种高效储能装置,钒电池电解液直接影响电池性能。本文以V2O3、V2O5和H2SO4为原料,化学合成了用于钒电池的V(Ⅲ)-V(Ⅳ)电解液,研究了无水乙醇与焦磷酸钠作为添加剂对电解液稳定性和电化学活性的影响。实验结果表明,当V2O3/V2O5质量比为7.2∶1时,可以得到V(Ⅲ)/V(Ⅳ)离子浓度比为1.0的电解液;添加剂的加入能提高电解液的稳定性和电化学反应活性。 相似文献
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对以高纯V2O5为原料、SO2还原V2O5法制备VOSO4的工艺及其反应机理进行了研究,计算了制备VOSO4的反应焓变和吉布斯自由能变化,并用制备的VOSO4作为钒电池的活性材料进行了充放电性能测试。结果表明:该法生产工艺简单,V2O5∶SO2∶H2SO4的最佳摩尔比为1∶1.10~1.15∶1.10~1.15。制备出的VOSO4中V4+的含量占总钒量的99.71%、V5+含量仅占0.29%,具有良好的充放电性能,可以作为钒电池电解液的活性材料。 相似文献
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采用传统工艺制备了微米级与采用溶胶-凝胶法制备了纳米级Li2SO4 Al2O3、Li2SO4 Na2SO4 Al2O3和Li2SO4 Li2WO4 Al2O3三种不同的H2S固体氧化物燃料电池质子传导膜,并用扫描电镜(SEM)对膜进行了表征,纳米膜的结构较致密和紧凑,性能较好.温度提高,电解膜的离子传导率开始增加,达到最大值后基本保持不变.实验结果表明,Li2SO4 Na2SO4 Al2O3和Li2SO4 Li2WO4 Al2O3复合膜比Li2SO4 Al2O3膜具有更好的传导性和电化学性能.复合Li2SO4 Li2WO4 Al2O3电解膜电池操作温度高于700℃时,其传导率与电化学性能较好.复合Li2SO4 Al2O3膜电池的操作温度较低,在650~700℃之间,其传导率与电化学性能较差.纳米电解膜的电池性能和化学稳定性比微米电解膜电池好.研究了由H2S、(MoS2 NiS Ag 电解质 淀粉)/ 电解膜/(NiO Ag 电解质 淀粉)、空气构成的燃料电池在680~750℃和101.13 kPa时的电化学特性,对纳米Li2SO4 Li2WO4 Al2O3复合膜电池,当操作温度为750℃时,电池的最大输出功率密度高达130 mW·cm-2,相对应的电流密度为175 mA·cm-2. 相似文献
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《应用化工》2022,(2):298-302
以甲基磺酸为溶剂,制备了用于氧化还原电池正极的钒电解液,并对不同自由酸浓度的电解液进行了电导率、粘度和热稳定性、电化学性能测试。结果表明,当CH3SO3H的浓度为2 mol/L时,电解液的导电性最好;随着CH3SO3H浓度的升高,电解液的粘度逐渐增大,钒离子的扩散系数逐渐降低。当自由酸的浓度为4 mol/L时,电解液具有良好的稳定性,电极过程的可逆性最好。以2 mol/L VO(CH3SO3)2+4 mol/L CH3SO3H为正极电解液组装的锌钒电池,充电以后的开路电压达1.96 V,前10个循环的放电平均中值电压为1.61 V,平均电流效率为96.12%,能量效率为74.03%。 相似文献
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以甲基磺酸为溶剂,制备了用于氧化还原电池正极的钒电解液,并对不同自由酸浓度的电解液进行了电导率、粘度和热稳定性、电化学性能测试。结果表明,当CH3SO3H的浓度为2 mol/L时,电解液的导电性最好;随着CH3SO3H浓度的升高,电解液的粘度逐渐增大,钒离子的扩散系数逐渐降低。当自由酸的浓度为4 mol/L时,电解液具有良好的稳定性,电极过程的可逆性最好。以2 mol/L VO(CH3SO3)2+4 mol/L CH3SO3H为正极电解液组装的锌钒电池,充电以后的开路电压达1.96 V,前10个循环的放电平均中值电压为1.61 V,平均电流效率为96.12%,能量效率为74.03%。 相似文献
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Redox transformations of vanadium species, deposited on the surface of a rutile monocrystal by annealing rutile with V2O5 were investigated by cyclic voltammetry. Two different vanadium species were observed at the surface: first, present in the crystal lattice of rutile, which undergoes the redox transformation V4+/V3+ only, and the second, present at the surface, which undergoes both the V5+/V4+ and V4+/V3+ redox transformations. The latter appears only when the subsurface layer becomes saturated with the former. 相似文献
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用(NH4)2SO4对钒渣钙化焙烧、稀酸浸取、化学沉淀净化后的酸性含钒溶液进行沉淀富集,考察了钒浓度、初始pH值、加铵系数(NH3/V摩尔比)、沉钒温度和时间对沉钒率及V2O5含量的影响,研究了沉钒动力学,对沉钒产物进行了表征. 结果表明,在初始pH为2.00?0.05、加铵系数1.5、温度大于95℃、沉钒时间120 min、钒液中V浓度大于20 g/L的条件下,沉钒率超过96%,产品中V2O5含量大于98%,杂质含量符合98级氧化钒的国家标准. 75~99℃下的沉钒过程可由Avrami动力学方程描述,表观活化能Ea=93.23 kJ/mol,指前因子A=9.14×1011 min?1. 铵盐沉钒产物为(NH4)2V6O16?1.5H2O,高温煅烧所得V2O5晶体为柱状,平均粒径1.25 ?m,主要杂质Mn以MnV2O6形式存在. 相似文献
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Kundapura Shantha Kalidindi B. R. Varma 《Journal of the American Ceramic Society》2000,83(5):1122-1128
Nanocrystalline bismuth vanadate (n-BiV) powders with a crystallite size of <50 nm have been prepared, at room temperature, by subjecting a stoichiometric mixture of bismuth oxide and vanadium pentoxide to mechanical activation. The n-BiV powders show enhanced sinterability, in comparison to the conventionally prepared micrometer-sized bismuth vanadate (m-BiV) powders and yield ceramics with a uniform microstructure. High-density (∼98% of the theoretical value), fine-grained (average grain size of ∼2 μm) ceramics, obtained using n-BiV have a high dielectric constant and a high pyroelectric coefficient and are associated with low dielectric loss, both at room temperature and at the transition temperature. These fine-grained ceramics show diffused phase transition and relaxor behavior, which are attributed to the irregular distribution of defects and/or compositional inhomogeneities in these ceramics. The fine-grained ceramics exhibit ferroelectric hysteresis loops with higher remanent polarization and lower coercive field values than the coarse-grained ceramics. 相似文献
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Zinc Vanadates in Vanadium Oxide-Doped Zinc Oxide Varistors 总被引:1,自引:0,他引:1
Huey-Hoon Hng Kevin M. Knowles Paul A. Midgley 《Journal of the American Ceramic Society》2001,84(2):435-41
Convergent-beam electron diffraction has been used to determine the space groups of β- and γ-Zn3 (VO4 )2 particles in vanadium oxide-doped zinc oxide varistors. The crystal structure of β-Zn3 (VO4 )2 has been determined to be monoclinic with space group P 21 and lattice parameters of a = 9.80 Å, b = 8.34 Å, c = 10.27 Å, and β= 115.8°, whereas that of γ-Zn3 (VO4 )2 is monoclinic with space group Cm and a = 10.40 Å, b = 8.59 Å, c = 9.44 Å, and β= 98.8°. Energy-dispersive X-ray microanalysis of these two phases shows significant deviations from their expected stoichiometry. It is apparent that the β-phase is, in fact, the metastable Zn4 V2 O9 phase, whereas the γ-phase either is a new oxide that consists of zinc, vanadium, and manganese or, more likely, is a zinc vanadate phase with a Zn:V atomic ratio of 1:1 that has the ability to go into solid solution with manganese. 相似文献
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铁水[Si]对转炉提钒钒渣质量影响较大,铁水[Si]抑制钒渣的氧化,钒渣渣态稀,导致钒渣品位下降、产渣率下降、半钢余钒偏高。通过采用提钒复吹工艺、在提钒终点加入碳质还原剂浓缩钒渣、预脱硅技术、优化提钒冷却剂、供氧时间和氧枪枪位等措施,钒渣品位由原来的15.2%提高到目前的16.2%。 相似文献
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Phase relations within the "V2 O3 –FeO" and V2 O3 –TiO2 oxide systems were determined using the quench technique. Experimental conditions were as follows: partial oxygen pressures of 3.02 × 10−10 , 2.99 × 10−9 , and 2.31 × 10−8 atm at 1400°, 1500°, and 1600°C, respectively. Analysis techniques that were used to determine the phase relations within the reacted samples included X-ray diffractometry, electron probe microanalysis (energy-dispersive spectroscopy and wavelength-dispersive spectroscopy), and optical microscopy. The solid-solution phases M2 O3 , M3 O5 , and higher Magneli phases (M n O2 n −1 , where M = V, Ti) were identified in the V2 O3 –TiO2 system. In the "V2 O3 –FeO" system, the solid-solution phases M2 O3 and M3 O4 (where M = V, Ti), as well as liquid, were identified. 相似文献
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钒铬还原渣是钠化提钒过程的典型危险固体废弃物,其资源化利用需求迫切。中国科学院过程工程研究所提出钒铬还原渣硫酸酸解-钒铬初步分离-铬/钒/铁络合深度分离技术路线,并在攀钢集团建成万吨级示范工程。本文重点考察钒铬还原渣酸解液中钒铬初步分离原理及工艺,研究了H2O2和Na2S2O8两种氧化剂对沉钒效果的影响,并通过实验确定了最佳工艺条件。结果表明:以H2O2为氧化剂时,H2O2与钒摩尔比为0.75、氧化温度为60℃、初始溶液pH为2.0、氧化时间为60min、水解温度为95℃、水解时间为2.5h的条件下可得到84.2%的沉钒率;以Na2S2O8为氧化剂时,Na2S2O8与钒摩尔比为0.65、氧化温度为90℃、氧化时间为45min、沉钒初始溶液pH为2.5、沉钒温度为90℃、沉钒时间为2.5h的条件下可获得93.1%的沉钒率。过硫酸钠氧化过程温和,沉钒率高,铬损失小,更适合工业推广应用。采用SEM获得了沉淀产物的微观形貌,煅烧后得到V2O5产品,采用XRF获得了产品组成,通过X射线衍射确定得到的V2O5产品为正交晶型。 相似文献
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Processing and Properties of Strontium Bismuth Vanadate Niobate Ferroelectric Ceramics 总被引:1,自引:0,他引:1
Yun Wu Chau Nguyen Seana Seraji Mike J. Forbess Steven J. Limmer Tammy Chou Guozhong Cao 《Journal of the American Ceramic Society》2001,84(12):2882-2888
The processing conditions, microstructure, and dielectric properties of strontium bismuth niobate vanadate ceramics, SrBi2 (V x Nb1− x )2 O9 (SBVN, with 0 ≤ x ≤ 0.3), were systematically studied. A relative density of >90% was obtained for all the samples using a two-step sintering process. XRD showed that a single phase with the layered perovskite structure of SrBi2 Nb2 O9 (SBN) was formed with a vanadium content of up to 30 at.%. SEM revealed that the average grain size decreased gradually with an increase in vanadium content. The Curie point was found to gradually increase from ∼418°C for SBN to ∼459°C for SBVN with 30 at.% vanadium. Dielectric constants at room temperature and their respective Curie points were found to peak at a composition with 10–15 at.%; vanadium. Moreover, a high concentration of vanadium (>5 at.%) resulted in a significant increase in tangent loss at low frequencies (<1000 Hz). The relationships between chemical composition, processing condition, microstructure, and dielectric properties of SBVN ferroelectric ceramics are discussed. 相似文献