Study of Ni Composite Anodes for Dimethyl Ether Fuel Cell

制备并表征了二甲醚(DME)固体氧化物燃料电池(SOFCs)系列Ni-Fe-La0.8Sr0.2Ga0.8Mg0.115Co0.085O3(LSGMC8.5)复合阳极,电极中Ni与Fe的摩尔比分别为9∶1、8∶2、7∶3、5∶5,电极中Ni-Fe的总质量分数为75%.利用多种技术考察了电极的物相组成,电极以及电极/电解质界面的微观结构,电极/电解质界面上进行的DME电化学氧化反应.结果表明,复合阳极中Fe含量的增加促进了电极的烧结,同时改变了电极/电解质界面的微观结构.电极催化DME电化学氧化的活性明显依赖于Ni、Fe的比例,Ni、Fe的摩尔比为8∶2的电极具有最高的电化学活性.Ni-Fe-LSGMC8.5电极具有较高的催化DME氧化反应的活性与稳定性,没有观察到电极中存在明显的积碳现象.Series of Ni-Fe-La0.8Sr0.2Ga0.8Mg0.115Co0.085O3(LSGMC8.5) composite anodes were prepared and characterized for solid oxide fuel cells(SOFCs) fueled with dimethyl ether(DME). The molar ratio of Ni to Fe was 9∶1, 8∶2, 7∶3, and 5∶5, respectively, and the total mass fraction of Ni-Fe in the electrode was 75%. Multiple techniques were applied to study the phase composition, the microstructure of the electrode, and the electrochemical oxidation of DME over the electrode/electrolyte interface. The results demonstrated that increase in the amount of Fe in the electrode improved the sintering activity of the electrode and changed the microstructure of the electrode and electrode/electrolyte interface. The activities for electrochemical oxidation of DME of the electrodes depended strongly on the molar ratio of Ni to Fe, and the electrode with a molar ratio of Ni to Fe at 8∶2 exhibited the highest activity. The electrodes showed good activity and stability for DME oxidation, and no obvious coke deposition was observed.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

Electrocatalytic Oxidation of Dimethyl Ether

考察了负载于镓酸镧基电解质上的镍电极与镍 钐掺杂氧化铈复合电极电催化二甲醚氧化反应的特性 .结果表明 ,反应的主要产物均为CO ,H2 和CH4,同时生成少量完全氧化的产物H2 O和CO2 .在开路电位下二甲醚发生裂解反应 ,生成的CO ,H2 和CH4三种主要产物的比例接近于 1.在有电泵氧存在下 ,二甲醚的电催化氧化反应强烈地依赖于阳极及电解质材料的组成 .Ni/La0 9Sr0 1Ga0 8Mg0 2 O3 界面上发生的主反应是二甲醚的部分氧化 ,且存在有严重的积碳现象 .电极中掺入SDC( 15 %Sm3 + 掺杂的CeO2 )后 ,二甲醚完全氧化性能明显增强 ;随着电流的增大 ,氢的生成速率显著减小 ,并生成大量的H2 O .采用掺钴镓酸镧基电解质后 ,Ni SDC主要表现为催化二甲醚部分氧化反应 ,且显著抑制了积碳的发生 .Ni SDC/La0 8Sr0 2Ga0 8 Mg0 11Co0 0 9O3 上二甲醚电催化氧化反应的主要产物为 1∶1的CO和H2 .掺钴电解质引起Ni SDC具有特殊的催化性能 ,可能与电解质中 p型电导的存在有关As potential fuel for solid oxide fuel cells, electrocatalytic oxidation of dimethyl ether (DME) was studied on nickel and nickel samarium doped CeO 2 composite anodes supported on series lanthanum gallate electrolytes. The reaction was characterized in a single solid oxide fuel cell, and the electrolytes were La 0 8 Sr 0 2 Ga 0 8 Mg 0 11 Co 0 09 O 3 (LSGMC9), La 0 8 Sr 0 2 Ga 0 8 Mg 0 13 Co 0 07 O 3 (LSGMC7), La 0 8 Sr 0 2 Ga 0 8 Mg 0 15 Co 0 05 O 3 (LSGMC5), and La 0 9 Sr 0 1 Ga 0 8 Mg 0 2 O 3 (LSGM). The composition of composite anode was 75%Ni 25%SDC (SDC15%Sm 3+ doped CeO 2). The main products were CO, H 2 and CH 4 with small amounts of CO 2 and H 2O. DME was decomposed into CO, H 2, and CH 4 under open circuit voltage. The product distribution depended strongly on the composition of anode and electrolyte. The major reaction on Ni/LSGM was partial oxidation of DME, and significant coke deposition was observed during the reaction. With the addition of SDC into Ni anode, complete oxidation was preferred on the catalyst. The formation rate of H 2 decreased with the increase of current on Ni SDC/LSGM, and large amount of H 2O was formed in the reaction. While using Co doped LSGM electrolytes, the major reaction changed to partial oxidation of DME, and the coke deposition was significantly decreased. The main products on Ni SDC/LSGMC9 were CO and H 2. The special property of Co doped LSGM electrolyte could be due to the high p type conductivity. Ni SDC/LSGMC is a kind of ideal anode for electrocatalytic partial oxidation of DME.日本教育部资助项目 (12 3 0 7

Effect of high temperature polarization on the performance of Ni8-Fe2-LSGMC5 composite anode

利用XRD、SEM及多种电化学技术,考察了高温原位极化对Ni8-Fe2-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ(LSGMC5)复合阳极性能的影响。高温极化改善了Ni-Fe复合阳极及电极/电解质界面的微观结构,减小了欧姆电阻和极化电阻,提高了电极的活性。极化没有改变复合阳极的物相,电极以Ni3Fe合金的形式存在。极化电流密度是决定电极性能的主要因素,在925℃下,随着极化电流密度由0 A/cm2增大至6 A/cm2,相应的电池在800℃下的最大功率密度由0.09 W/cm2增加至1.00 W/cm2。The effect of in-situ polarization at high temperature on the performance of Ni8-Fe2-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ(LSGMC5) composite anode was studied by using XRD,SEM and multiple electrochemical techniques.The microstructure of the Ni-Fe composite anode and the anode/electrolyte interface was improved by polarization at high temperature,the ohmic resistance and polarization resistance were decreased.The polarization did not change the phase composition of the composite anode,the electrodes were existing in the form of Ni3Fe alloy.Polarization current densities were the key factors to determine the performance of the electrode.The maximum power density at 800 ℃ of the cell increased from 0.09 W/cm2 to 1.00 W/cm2 while the polarization current density at 925 ℃ increased from 0 A/cm2 to 6 A/cm2.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

Effects of the Concentration of LSGMC5 on the Performance of Ni-Fe Composite Anodes for Dimethyl Ether Fuel Cells

用浸渍法制备了掺杂不同质量分数的La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05_O_(3-δ)(LSGMC5)粉末的Ni8-Fe2-LSGMC5复合阳极,并采用交流阻抗和直流极化技术考察了以氢气和二甲醚为燃气时该复合阳极的电化学性能及相应电池的功率输出特性.结果表明,在电极中掺入LSGMC5粉末,能显著地改善电极的形貌和电极/电解质界面结构,减小欧姆电阻和极化电阻.电极中LSGMC5粉末含量对于氢气及二甲醚电化学氧化性能的影响显著不同.以二甲醚为燃气时,电极极化电阻随LSGMC5粉末含量的增加而减小,其中LSGMC5掺杂量为30%的复合阳极具有最高的电化学性能,相应电池在1073、1023、973K时的输出功率分别为1.00、0.61、0.40W·cm~(-2);以氢气为燃气时,LSGMC5掺杂量为20%的复合阳极具有最好的电化学性能,随着LSGMC5掺杂量的进一步增加,电极极化电阻显著增大.Ni8-Fe2-LSGMC5 composite anodes doped with various amounts of La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05_O_(3-δ) (LSGMC5) were prepared by using the impregnation method. The electrochemical properties of the anodes and the power generation characteristics of corresponding cells were studied by alternating current (AC) impedance spectrometry and direct current (DC) polarization using hydrogen and dimethyl ether as fuels, respectively. The results showed that the introduction of LSGMC5 powders into the Ni-Fe anodes improved the structure of the anodes and the anode/electrolyte interfaces significantly, which decreased the Ohmic resistance of the cell and the polarization resistance of the anodes. The LSGMC5 powders in the composite anodes showed different effects on the electro-catalytic oxidation of hydrogen and dimethyl ether (DME). The polarization resistance of the anode decreased with increasing concentration of LSGMC5, and the anode containing 30% LSGMC5 powder showed the best electrochemical properties when using DME as a fuel. The maximum power densities of the cell in DME based on the anode containing 30% LSGMC5 powder reached 1.00, 0.61, and 0.40 W·cm~(-2) at 1073, 1023, and 973 K, respectively. The anode doped with 20% LSGMC5 powder had the best electrochemical properties when using H_2 as a fuel, with the further increase in the amount of LSGMC5 powder the polarization resistance increased quickly.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

磁性抛光对3D打印微结构的参数影响

对微结构精密加工时要能够控制高低不平的材料去除,以保证不破坏微结构原来的三维形貌特征。通过自行搭建的实验平台对3D打印出来的微结构工件进行抛光实验,主要研究了机床主轴转速、加工间隙、抛光时间和抛光路径等工艺参数对微结构抛光后的三维轮廓材料去除特性以及微结构的保形情况。实验结果表明:微结构保形系数随着抛光时间增加而变小,而主轴转速和加工间隙的变化对保形系数影响较小;采用等高线移动式抛光的保形系数比采用水平移动式大;相同工艺参数抛光对包体状和圆环阵列微结构工件保形效果较好,对三棱锥工件保形效果较差。国家自然科学基金(51675453);;深圳市科技计划项目(JCYJ20160517103720819

Study on Remove of Free-Form Surface Structure by Magnetic Polishing

磁性抛光因柔性工具的工件表面适应性高而具有较好的应用潜力。自行设计抛光工具头,制备磁性抛光体,搭建试验平台,并对不锈钢平面工件进行定点抛光试验,平均去除效率为0.231μm/10min,且工件表面质量得到了很大的改善,验证了该磁性抛光方法的可行性。继而对两种自由曲面结构工件进行抛光：一是采用工具头水平移动式、工具头等高线移动式两种不同的抛光进给运动方式对不同曲率的不锈钢工件进行抛光去除试验,试验证明：两种抛光方式对每个曲率的轮廓均有去除能力,去除量在0.14~1.33μm之间;二是对3D打印的光敏树脂微结构自由曲面定点抛光,单位时间去除效率在8.957~12.587μm/10min之间,且改善了轮廓的光滑度。初步试验表明,磁性抛光方法对两种自由曲面结构均有一定的去除能力,可进一步探索磁性抛光技术应用于自由曲面结构确定性抛光。Magnetic polishing technique has wide application potential due to the high adaptability of flexible tool to the workpiece surface. The relevant polishing tools were developed, and a test platform was established in the paper. The workpiece finish had been greatly improved after spot polishing on stainless steel flat parts, and the average removal efficiency was 0.231μm/10 min, which verified the feasibility of the magnetic polishing method. Then two kinds of free-form surface structures were polished by magnetic polishing method. First, stainless steel parts with different curvatures were polished by two different polishing feed movement ways. Experimental results showed that two polishing methods had the ability to remove the contours of each curvature, and the removal amount falls between 0.14-1.33μm. Secondly, the removal efficiency was between 8.957-12.587μm/10 min after spot polishing the microstructured free-form surface, and the smoothness of the contour is improved. Preliminary experiments showed that the magnetic polishing method had the ability to remove both free-form surface structures, so it can explore further magnetic polishing technology used in deterministic polishing of free-form surface structure.深圳科技计划项目（JCYJ20160517103720819

Preparation of Sm_(0.5)Sr_(0.5)CoO_3-La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3 Composite Cathodes Using Wet-chemistry Method and the Characterization of Their Properties

用湿化学法制备了Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)中温固体氧化物燃料电池复合阴极,其中SSC用甘氨酸-硝酸盐法合成,LSGMC5用柠檬酸盐法合成.XRD结果表明,甘氨酸-硝酸盐法制备的SSC在焙烧温度大于1223K即表现为单一的钙钛矿结构.随焙烧温度的升高,SSC粉末颗粒增大,导致相应电极与电解质的结合变差.复合电极的性能显著依赖于SSC粉末的焙烧温度,其中含1223K焙烧SSC粉末的电极表现出最小的欧姆电阻以及电极电阻.973K、氧气中、1A·cm-2电流密度下该电极的极化过电位仅为0.077V,远小于固相法合成的电极.Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cells were prepared using wet-chemistry method. The SSC powders were prepared using the glycine-nitrate method and the LSGMC5 powders were synthesized using the citrate method. The XRD pattern of SSC powders calcined at temperatures higher than 1223 K corresponded to a desired perovskite structure. With the increase in calcining temperature, the size of the SSC particles increased, which leaded to a weak adhesion to the electrolyte for corresponding electrodes. The performance of the SSC-LSGMC5 composite electrodes depended strongly on the calcining temperature of SSC powders, and the electrodes based on SSC calcined at 1223 K exhibited the lowest ohmic resistance and polarization resistance. The overpotential at 973 K in oxygen under 1 A· cm-2 current density was as low as 0.077 V, which was much lower than that of electrodes prepared using solid-state reaction.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

Effect of preparation method for LSGMC5 on the performance of SSC-LSGMC5 composite cathodes

制备了Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)中温固体氧化物燃料电池(ITSOFC)复合阴极,其中LSGMC5用柠檬酸盐法和固相合成法合成。含有柠檬酸盐法合成的LSGMC5粉末的SSC-LSGMC5电极的氧还原电催化性能明显优于含固相合成法合成的LSGMC5的电极。随着焙烧温度的升高,柠檬酸盐法合成的LSGMC5粉末的颗粒变大,并致密化,导致相应SSC-LSGMC5复合电极与LSGMC5电解质的结合程度减弱以及氧还原电催化性能变差。复合阴极中柠檬酸盐法合成的LSGMC5粉末的最佳焙烧温度约为1 000℃。Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5) composite cathodes for intermediate temperature solid oxide fuel cell(ITSOFC) were prepared.LSGMC5 powders were synthesized by the citrate method and the solid-state reaction.The oxygen reduction electrocatalysis activity of SSC-LSGMC5 electrodes containing LSGMC5 prepared by the citrate method was much higher than that containing LSGMC5 prepared by the solid-state reaction.With the increasing of the sintering temperature,the size of the LSGMC5 particles prepared by the citrate method increased and the particles were densification.The contact between the corresponding SSC-LSGMC5 composite electrode and LSGMC5 electrolyte was weakened,and the oxygen reduction electrocatalysis activity was reduced.The optimum sintering temperature for LSGMC5 powders prepared by the citrate method in the composite cathode was about 1 000 ℃.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资

应收项目、应付项目的信息含量差异及其影响——以融资成本与公司价值为视角的实证研究

2019年初,财政部将2018年中归并的"应收票据及应收账款"项目、"应付票据及应付账款"项目改回分项列报。这类会计科目的分开列报,与我国改革开放和企业实际情况密切相关,从宏观上体现了会计信息"决策有用性"这一最重要的目标。我国的票据信用基础与美国存在本质差别,基于社会学"权力-依赖关系"和战略管理的价值链思想,"应收账款"与"应收票据"、"应付账款"与"应付票据"这四个报表项目实际上反映了企业在价值链中不同的竞争力和权力关系,其不仅可能影响融资成本,而且可能直接影响企业价值。据此构建研究假设,利用我国上市公司2007—2017年相关数据所进行的实证研究可分别检验这四个会计项目对融资成本和企业价值的影响,借此证明其可能隐含着不同的信息含量。研究结果表明,这四个报表项目对企业融资成本和价值影响不同,具有不同信息含量。因此,这四个项目分开列报更符合中国国情,经济含义更明确,会计信息含量更高。国家自然科学基金重大项目“基于中国情景的会计、审计与公司财务关键科学问题研究”(71790600);国家自然科学基金重大项目“中国制度和文化背景下公司财务政策的理论与实践研究”(71790601);国家自然科学基金重点项目“金融政策对企业投融资行为的影响研究”(71532012

Study on Ni-Fe-LSGMC8.5 composite anode

制备并表征了Ni-Fe-LSGMC8.5复合阳极,电极中的n(Ni)∶n(Fe)分别为9∶1、8∶2、7∶3和5∶5。结果表明:复合阳极中的Ni和Fe以合金的形式存在,Fe含量的增加促进了电极的烧结,同时改变了电极/电解质界面的微观结构。当电极中的n(Ni)∶n(Fe)为8∶2和7∶3时,电极具有最高的电化学活性以及最小的欧姆电阻。当阳极中的n(Ni)∶n(Fe)为8∶2时,组成的Ni-Fe-LSGMC8.5|LSGMC5|SSC-LSGMC5电池在800℃、750℃、700℃和650℃下,最大功率密度分别达到1.20W/cm2、0.92 W/cm2、0.60 W/cm2和0.39 W/cm2。Ni-Fe-LSGMC8.5 composite anodes were prepared and characterized,in which the molar ratio of Ni/Fe was 9∶1,8∶2,7∶3 and 5∶5,respectively.The results showed that the Ni and Fe in the anode existed in the form of Ni-Fe alloy.The increase of Fe in the electrode led to a sintering of the electrode particles as well as a change in the microstructure of the electrode/electrolyte interface. When the molar ratio of Ni and Fe was 8∶2 and 7∶3,the anodes exhibited the highest electrochemical activity and the lowest ohmic resistance.Ni-Fe-LSGMC8.5｜LSGMC5｜SSC-LSGMC5 cell using the anode with the molar ratio of Ni and Fe (8∶2),gave the maximum power density of 1.20 W/cm~2,0.92 W/cm~2,0.60 W/cm~2 and 0.39 W/cm~2 at 800 ℃,750 ℃,700 ℃ and 650 ℃,respectively.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资