Study of the efficiency of composite LaNi0.6Fe0.4O3-based cathodes in intermediate-temperature anode-supported SOFCs

The paper focuses on the performance comparison of LaNi_0.6Fe_0.4O_3-δ (LNF) composite cathodes comprising Ce_0.8Sm_0.2O_1.9 (SDC) and Bi_1.5Y_0.5O₃ (YDB) electrolytes and La_0.6Sr_0.4Fe_0.8Co_0.2O_3-δ (LSFC)-SDC cathodes in anode-supported SOFCs with YSZ/GDC electrolyte films obtained by magnetron sputtering. Cathodes with LNF-SDC and LNF-YDB functional layers and the LNF-YDB-CuO oxide collector show a sufficient thermo-mechanical compatibility with the electrolyte. The performance of the anode-supported SOFC with the LNF-YDB/LNF-YDB-CuO cathode, reaches 650 and 1050 mW/cm² at 700 and 800 °C, respectively, which is significantly higher than that obtained in other works for anode-supported cells with LNF cathodes. The initial total polarization resistance of the NiO-YSZ/YSZ/GDC/LNF-YDB/LNF-YDB-CuO cell, is 0.53 Ω cm², which is lower than the initial resistance of the similar anode-supported cell with the LNF-SDC/LNF-YDB-CuO cathode (1.35 Ω cm²) and LSFC-SDC cathode with LNF-YDB-CuO (1.71 Ω cm²) and La_0.6Sr_0.4CoO₃ (1.17 Ω cm²) collectors. The most probable reason for the LNF-YDB electrode aging is the growth of Bi-containing particles. Experimental results show that LNF-based composite cathodes are competitive with cobalt-containing cathodes and can be promising for anode-supported SOFCs with decreased operating temperature, that allows extending the material choice for both functional and collector cathode layers.     

Non-alloy Mg anode for Ni-MH batteries: Multiple approaches towards a stable cycling performance

Mg attracts much research interest as anode material for Ni-MH batteries thanks to its lightweight, cost-effectiveness and high theoretical capacity (2200 mA h g^?1). However, its practical application is tremendously challenged by the poor hydrogen sorption kinetics, passivation from aggressive aqueous electrolytes, and insulating nature of MgH₂. Mg-based alloys exhibit enhanced hydrogen sorption kinetics and electrical conductivity, but significant amount of costly transition metal elements are required. In this work, we have, for the first time, utilized non-alloyed but catalyzed Mg as anode for Ni-MH batteries. 5 mol.% TiF₃ was added to nanosized Mg for accelerating the hydrogen sorption kinetics. Several strategies for preventing the problematic passivation of Mg have been studied, including protective encapsulation of the electrode and utilizing room-temperature/high-temperature ionic liquids and an alkaline polymer membrane as working electrolyte. Promising electrochemical performance has been achieved in this Mg–TiF₃ composite anode based Ni-MH batteries with room for further improvements.     

基于电化学阻抗法的质子交换膜燃料电池“三步活化法”机理研究

活化能够有效地发挥质子交换膜燃料电池膜电极的性能,"三步活化法"是其中一种比较理想的方法。为了研究"三步活化法"活化质子交换膜燃料电池的机理,利用电化学阻抗谱测试"三步活化法"过程中的膜电极阻抗,并建立等效电路模型拟合所得实验数据。结果表明,"三步活化法"可以有效降低欧姆阻抗、阳极法拉第阻抗、阴极法拉第阻抗以及阴极传质阻抗,这表明"三步活化法"有利于电子、质子、气体与水的传输通道的形成。     

Nonlinear radiation on Maxwell fluid in a convective heat transfer with viscous dissipation and activation energy

The present analysis addresses linear and nonlinear radiation effects in hydrodynamic viscous Maxwell fluid flow on a unidirectional stretching surface through viscous dissipation. The relaxation effect is considered in the mathematical model, which elucidates mass transport mechanisms under binary chemical reaction and activation energy. Mathematical modeling contains nonlinear partial differential equations using boundary conditions. Appropriate transformations convert the partial differential equations into ordinary differential equations. Numerical solutions for regular differential equations are brought by Runge–Kutta–Fehlberg numerical quadrature and a shooting method with a tolerance level of 10⁻⁹. The influence of physical variables, such as Deborah relaxation number, rotation parameter, Biot number, activation energy parameter, reaction rate parameter, Eckert number, and Prandtl number are investigated. Increasing the Biot number improves the temperature region in the boundary layer. With high rotation, the increasing Deborah number enhances the fluid temperature substantially throughout the boundary layer.     

废旧磷酸铁锂电池再生及湿法回收技术研究进展

对现有废旧磷酸铁锂电池回收技术进行了总结, 简要介绍了废旧磷酸铁锂正极材料再生修复技术现状, 重点评述了湿法冶金选择性浸出废旧磷酸铁锂技术原理和现有技术方案的研究进展, 并对一些回收新技术进行了简述。通过对比不同技术方案的优劣势, 对废旧磷酸铁锂电池回收提锂技术发展趋势进行了展望。     

假槟榔花基多孔炭材料的制备及其电化学性能研究

以假槟榔花为原料, 经高温碳化和氢氧化钾活化制备得到假槟榔花基多孔炭材料。采用XRD、SEM、热重分析仪、比表面积及孔径分析仪等对多孔炭材料进行表征和分析, 用电化学工作站和恒流充放电测试仪测试其电化学性能。结果表明, 假槟榔花基多孔炭材料为无定形炭材料, 为纳米片层结构, 比表面积为1 223.32 m²/g。三电极体系中, 以1 mol/L H₂SO₄和6 mol/L KOH为电解液, 电流密度为0.5 A/g时, 其放电比电容分别为145 F/g和105 F/g; 20 A/g电流密度下, 放电比电容分别为100 F/g和80 F/g。二电极体系中, 在酸和碱条件下, 1 A/g电流密度下循环5 000圈, 其电容保持率均在98%以上。该材料具有高的比表面积和纳米片层结构, 有利于提高材料的电荷储存能力, 材料具有良好的超级电容器特性。     

Prospects of enhancing the understanding of material-hydrogen interaction by novel in-situ and in-operando methods

A main scientific and technical challenge facing the implementation of new and sustainable energy sources is the development and improvement of materials and components. In order to provide commercial viability of these applications, an intensive research in material-hydrogen (H) interaction is required. This work provides an overview of recently developed in-situ and in-operando H-charging methods and their applicability to investigate mechanical properties, H-absorption characteristics and H embrittlement (HE) susceptibility of a wide range of materials employed in H-related technologies, such as subsea oil and gas applications, nuclear fusion and fuel cells.     

高渗透性环氧系灌浆材料及其应用

 添加剂YDS能"活化"惰性"稀释剂,在此基础上开发成功的新型高渗透性环氧系灌浆材料,具有极高的渗透性,对常见介质有较高的亲和力,固结体的力学性能优良而且成本较低,适用于大坝的低渗透软弱基础固结补强和混凝土裂隙的补强防渗等。并举例说明了这种浆材的实际使用效果。     

铌钒微合金钢的动态再结晶行为

针对柴油机喷油管用Nb、V微合金钢,采用热模拟压缩试验,研究了高温形变条件下,微合金钢的动态再结晶行为。结果表明,试验钢在1100℃、变形量60%、变形速率0.1 s-1条件下,可得到均匀细小的晶粒组织,试验钢动态再结晶激活能为349.451 kJ/mol;在较高温度和较低应变速率下,试验钢易于发生动态再结晶,而在较低温度和较高应变速率下易于发生形变诱导铁素体相变。     

Effects of Carbon Content and Microstructure on Corrosion Property of New Developed Steels in Acidic Salt Solutions

New steels with different carbon contents were self-developed by thermo-mechanical controlled processing.The effects of the carbon content and the microstructure on the corrosion properties of new steels were investigated by immersion test and SEM.The results indicated that the ferrite phase（both the proeutectoid and eutectoid ferrite） dissolved preferentially.Cementite reserved and accumulated on the surface.As carbon content increased,the content of ferrite decreased and cathode/anode area ratio increased.Therefore,the corrosion rate of new steels increased from 0.30 to0.90 mm/years when the carbon content rose from 0.05 to 0.13 wt%.The corrosion process of new steels was studied using electrochemical impedance spectroscopy experiments during 72 h.It indicated that the impedance modulus |Z|_0.01 Hz of the new steels reduces with the increase of the immersion time.While the corrosion process of the new steel with 0.11 wt%C developed faster than that with 0.07 wt%C,although their |Z|_0.01 Hz was similar at the initial stage.