Institutional Repository of Ningbo Institute of Material Technology & Engineering, CAS

    电池堆密封材料、燃料电池堆密封结构及其制作方法

    No full text
    一种电池堆密封材料,采用玻璃陶瓷非晶材料,该玻璃陶瓷非晶材料包括有如下重量百分比的组分Al2O3 10~17;SiO2 35~55;CaO 28~38。本发明还公开了该电池堆密封材料在固体氧化物燃料电池堆中的应用结构及相应的制作方法。与现有技术相比,本发明的优点在于:本发明适用于中低温固体氧化物燃料电池堆单电池与不锈钢中间连接件、不锈钢中间连接件之间的密封,密封材料与SUS430不锈钢的界面润湿性能良好,表明具有优异的热循环密封性能;由本发明制作的电池堆密封结构测试得到长时间稳定的电池电压和优异的热循环性能

    一种原位合成纳米氧化锡/碳纳米管复合材料的方法

    No full text
    本发明公开了一种原位合成纳米氧化锡/碳纳米管复合材料的方法,它主要以无机锡盐、碳纳米管和碱源为原料,实验流程主要包括前驱体制备、水热反应、沉淀物洗涤干燥等步骤,其主要优点在于:采用水热法实现了纳米氧化锡在碳纳米管表面的原位沉积和生长,所得SnO2纳米粒子粒径小且均匀(小于10nm),结晶良好,均匀包覆在碳纳米管的表面,与碳纳米管结合紧密,该复合材料在气敏传感器材料、锂离子电池的阳极材料等方面具有潜在的应用前景,本方法没有添加任何表面活性剂,原料简单易得,工艺简单无污染,制备周期短,反应条件温和,成本低,适宜规模化生产,是一种环境友好型的合成方法

    Phase Transition and Oxygen Ion Diffusion in (La_(1-x)Ln_x)_2Mo_2O_9 (Ln=Nd, Gd, x=0.05-0.25) Using Dielectric Relaxation Method

    No full text
    Dielectric relaxation method was employed to study the properties of oxygen ion diffusion and phase transition in the oxide-ion conductors (La_(1-x)Ln_x)_2Mo_2O_9 (Ln = Nd, Gd, x = 0.05-0.25). Two dielectric loss peaks were observed: peak Pd at about 600 K and peak Ph around 720 K. Peak Pd is a relaxational peak and associated with the short-range diffusion of oxygen ions, while peak Ph hardly changes its position and dramatically decreases in height with increasing frequency, exhibiting non-relaxational nature. With increasing Ln~(3+) concentration, the heights of peak Ph and Pd increase at first and then decrease after passing a maximum at 15% doping. It is suggested that peak Ph is related to the phase transition of a static disordered state to a dynamic disordered state in oxygen ions/vacancies distribution. It is found that the 15%Gd or 15%Nd doped La_2Mo_2O_9 samples exhibit the highest conductivity in accordance with the highest height of peak Pd at this doping content

    纳米复合钕铁硼磁体的矫顽力模型及影响因素综述

    No full text
    总结了纳米复合钕铁硼磁体的矫顽力模型,并分析了晶间交换耦合作用、相互作用畴、静磁耦合作用及添加元素等对矫顽力的影响.当晶粒尺寸较小时,晶间交换耦合作用的增强和相互作用畴的存在不利于矫顽力的提高;静磁耦合作用对矫顽力的影响还存在争论,有待于进一步的研究

    氧化石墨烯电阻型存储材料的研究

    No full text
    在新型非易失性存储器中,基于电致电阻效应的电阻型存储器(RRAM)以其结 构简单、存储密度高、读写速度快、功耗低、与传统CMOS 工艺兼容性好等优点而 被广泛研究。目前发现的RRAM 候选材料很多,但没有一种材料能完全达到实用化 的要求,RRAM 电阻转变机理仍不明确,因此,开发新型存储材料、揭示RRAM 电 阻转变机制,仍是RRAM 发展的关键。 氧化石墨烯(GO)表面含有大量亲水性官能团,在水中分散性好,易于大面积 均匀成膜,通过改变含氧官能团的含量,可以调节GO 的能带结构和导电特性,因此 在微电子领域有很好的应用前景。本文研究了GO 薄膜的电致电阻效应,探讨了GO 薄膜作为RRAM 存储材料的可能性。 首次在GO 薄膜中观察到了稳定的电致电阻效应,开关比约为20,开关电压低 于1 V,并具有良好的抗疲劳性和数据保持性(高低阻态可以稳定保持200 天以上)。 研究了顶电极材料、GO 薄膜厚度、顶电极面积、限流对GO 薄膜电阻转变效应 Forming 电压、初始电阻、高低阻态阻值等方面的影响。研究结果表明GO 薄膜电致 电阻效应的初始电阻、Forming 电压随着金属功函数的增加而增大(Ag 电极除外), 随着GO 薄膜厚度的增加而增大,随着顶电极面积的增加,呈现递减趋势,而开关电 压和高低阻态阻值受薄膜厚度、顶电极面积等因素影响不大; Reset 电流随限流线性 增大,低阻态电阻随限流的增大而减小,因此可以通过改变限流来控制RRAM 器件 的功耗并可以实现多态存储。 采用导电原子力显微镜(CAFM)对GO 薄膜进行了导电性测量,在微观尺度观 察到了薄膜的电致电阻现象。CAFM 观察到的写入-擦除过程与半导体参数分析仪的 宏观测量结果一致。研究表明GO 薄膜器件高阻态的导电行为服从缺陷控制空间电荷 限制电流机制,变温特性表现为半导体导电特性,低阻态服从欧姆导电机制,变温特 性表现为金属导电特性,探讨了GO 薄膜中电阻转变效应可能的物理机制,包括金属 导电丝模型及含氧基团的脱附与吸附模型

    Gd掺杂的CeO2纳米粉体及阻挡层的制备与物性研究

    No full text
    Gd doped CeO2(CGO)is one of the most attentive electrolyte materials, which could reduce the operation temperature of solid oxide fuel cells (SOFCs) to intermediate temperature (600℃~800℃). In this paper, Acrylic acid modified sol-gel method is employed to prepare nanoscale Ce0.8Gd0.2O2-δ and Ce0.85Gd0.15O2-δ powders,PVP or PEG is used as dispersant to solve the agglomeration of CGO powders. The CGO powders prepared exhibited a narrow particle size distribution,the average particle size is ca.20nm,the BET special area surface of Ce0.8Gd0.2O2-δ and Ce0.85Gd0.15O2-δ powders could reach 56.69m2g-1 and 62.18m2g-1 respectively. The CGO powders exhibited a high sintering activity, the wafer prepared by squash method and sintered at 1350 ha℃s the highest densification, and the relative density could reach 95%. The conductivity of Ce0.8Gd0.2O2-δ and Ce0.85Gd0.15O2-δ powders is 0.024S cm-1 and 0.011S cm-1 respectively. The anode-supported SOFC using Ni-YSZ as anode, YSZ as electrolyte, LSCF-CGO as cathode need an interlayer to prevent the reaction between YSZ electrolyte and LSCF cathode. In this paper, CGO interlayer is obtained by spray coating method, the influence of CGO powders pre-sintering temperature, addition of PVP, planetary milling process and sintering temperature on the structural properties is studied systematically. The optimized preparation condition is CGO powders pre-sintered at 750℃,planetary ball milling for 48h by Φ2mm ball, 6wt%PVP added and sintering temperature of above 1250℃, which can prevent the interfacial reaction between YSZ electrolyte and LSCF cathode efficiently. The single cell with CGO interlayer sintered above 1250℃ exhibited area special ohmic resistance (ASR) of below 0.192Ωcm2 at 850 and average maximum power density ℃of above 600mW cm-2 at 750.℃Gd掺杂的CeO2(CGO)是目前最受关注的电解质材料之一,CGO电解质可以将固体氧化物燃料电池的运行温度降低到中低温(500℃~800℃)。本文用丙烯酸改进的溶胶凝胶法制备纳米Ce0.8Gd0.2O2-δ和Ce0.85Gd0.15O2-δ粉末,通过加入分散剂PVP或PEG解决CGO粉体的团聚问题。该法制备的Ce0.8Gd0.2O2-δ和Ce0.85Gd0.15O2-δ粉体的粒径约为20nm,颗粒分布均一,比表面积分别高达56.69m2g-1和62.18 m2 g-1。粉体烧结活性较高,用压片法制备的该粉体的圆片在1350℃下烧结达到最高的致密度,相对致密度达到95%。在650℃下Ce0.8Gd0.2O2-δ和Ce0.85Gd0.15O2-δ的电导率分别为0.024S cm-1和0.011 S cm-1。 对Ni-YSZ为阳极支撑、YSZ为电解质、LSCF-CGO为复合阴极的单电池,需要在YSZ电解质和LSCF阴极之间制备一层阻挡层。本文研究了湿法喷涂制备CGO阻挡层过程,考察了粉体预处理温度、PVP用量、行星球磨和烧结温度对CGO阻挡层结构和性能的影响。实验证明CGO阻挡层的最佳制备条件为:粉体预处理温度为750℃、Φ2mm的氧化锆球球磨48h、PVP用量为6wt%、烧结温度为1250℃~1300℃。制备的CGO阻挡层能够成功地阻挡YSZ电解质和LSCF阴极的反应。在850℃下,单电池欧姆电阻小于0.192Ω cm2;在750℃下,单电池的最大功率密度高于600 mW cm-2

    Controlled synthesis of mesoporous carbon modified by tungsten carbides as an improved electrocatalyst support for the oxygen reduction reaction

    No full text
    Mesoporous carbon was modified with tungsten carbides by the carbothermal hydrogen reduction of a layer of chemisorbed 1:12 phosphotungstic anions (PW12O403-) on carbon surfaces. Depending on the temperature of carbothermal treatment, different tungsten species, i.e., W, W2C, WC, were formed on the carbon matrix. No significant changes in both surface areas and mesostructures were observed during the formation of various tungsten species on carbon surfaces under high-temperature conditions. A uniform dispersion of Pt nanoparticles (1-6 nm) can be achieved via nanoconfinement on the surfaces of both mesoporous carbon and tungsten carbide-modified mesoporous carbon. Pt nanoparticles supported on mesoporous carbons modified with tungsten carbide (Pt/WC-C) exhibit enhanced electrocatalytic activities relative to the control, in which mesoporous carbons without carbide modification were directly used as a support (Pt/C). In addition, both enhanced thermal stability and good electrochemical stability were observed for the Pt/WC-C electrocatalyst. Published by Elsevier B.V
    Institutional Repository of Ningbo Institute of Material Technology & Engineering, CASis based in CN
    Repository Dashboard
    Do you manage Institutional Repository of Ningbo Institute of Material Technology & Engineering, CAS? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!