Study of Sm0.5Sr0.5CoO3- La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 Composite Cathodes Synthesized by Using the Wet Chemistry Method

Sm0.5Sr0.5CoO3是一种较好的ITSOFC阴极材料，负载于镓酸镧电解质上的Sm0.5Sr0.5CoO3－La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(SSC-LSGMC5)复合阴极表现出高的活性与稳定性。SSC-LSGMC5复合阴极制备方法的探索及氧还原机理的研究对于开发高性能阴极材料具有重要意义。本文采用湿化学法制备了SSC-LSGMC5复合阴极，利用多种电化学技术对电极上的氧还原反应动力学进行了研究。首次用湿化学法制备了SSC-LSGMC5复合电极。SSC-LSGMC5复合阴极中的SSC及LSGMC5粉分别采用甘氨酸－硝酸盐法和柠檬酸盐法合成。相对于固相合成法，湿化...Sm0.5Sr0.5CoO3(SSC) is a kind of good ITSOFC cathode materials. Sm0.5Sr0.5CoO3－La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (SSC-LSGMC5) composite cathodes supported on lanthanum gallate exhibit high activity and stability. The study of the synthesizing method and the kinetics of oxygen reduction of SSC-LSGMC5 is essential for the development of high performance cathode materials. In this study, SSC-LSGMC5 compo...学位：理学硕士院系专业：化学化工学院化学系_化学学号：20032512

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

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

Improving the performance of SOFCs cathode by using an interlayer based on the electrolyte material

利用在SSC-LSGMC5复合电极与LSGMC5电解质片之间加入与电解质相同材料的夹层的方法,提高了电极性能。不同温度下,在LSGMC5电解质片上印刷了厚度为2~5μm的LSGMC5薄膜,在薄膜上印刷了SSC-15%LSGMC5复合电极,并进行了表征。SEM结果表明:当夹层焙烧温度大于1 400℃时,夹层为致密结构,并与电解质完好地结合在一起,夹层与电极的结合程度远优于无夹层的电极|电解质界面。在700℃纯氧条件下,夹层(1 400℃焙烧)的引入,使电极极化电阻由0.38Ω.cm2减小至0.12Ω.cm2,1 A/cm2下的极化过电位由0.23 V减小至0.10 V。LSGMC5 interlayer was added between SSC-LSGMC5 composite electrode and LSGMC5 electrolyte flake,which had improved the cathode performance.The LSGMC5 interlayer was sintered on the LSGMC5 electrolyte flake at various temperatures,the thickness was about 2～5 μm.The SSC-15% LSGMC5 composite electrode was printed on the sintered interlayer and its performance was analyzed.SEM images exhibited that LSGMC5 interlayer well coated on the electrolyte was dense while the interlayer was sintered at a temperature higher than 1 400 ℃.The coating degree of the electrode｜interlayer interface sintered at high temperatures was better than that of the electrode｜electrolyte interface without an interlayer.The polarization resistance of cathode decreased from 0.38 Ω·cm~2 to 0.12 Ω·cm~2 and the polarization over-potential under 1 A/cm~2 decreased from 0.23 V to 0.10 V at 700 ℃ in oxygen by using an LSGMC5 interlayer calcined at 1 400 ℃.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资助项

Preparation of Sm0.5Sr0.5CoO3-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 composite cathodes using wet-chemistry method and the characterization of their properties

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

Effect of a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3 interlayer synthesized by the citrate method on the cathode performance

考察了在Sm0.5Sr0.5CoO3(SSC)-La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5)/LSGMC5界面中加入柠檬酸盐法合成的LSGMC5夹层对界面的影响。考察了含不同温度焙烧的LSGMC5夹层的SSC-LSGMC5/LSGMC5/LSGMC5组合的微观结构及电化学性能。当夹层焙烧温度高于1 623 K时,夹层与电极的结合优于无夹层的电极/电解质界面,具有大的两相界面面积及三相界面长度。制备的组合的氧还原性能依赖于夹层以及电极的焙烧温度,含有1 673 K烧结夹层、1 123 K焙烧电极的样品具有最高的活性。与含固相法制备的LSGMC5夹层的样品相比,采用含柠檬酸盐法制备的夹层的组合具有更小的欧姆电阻及更高的氧还原活性。The effect of the addition of a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3(LSGMC5) interlayer synthesized by the citrate method into the Sm_(0.5)Sr_(0.5)CoO_3(SSC)-LSGMC5/LSGMC5 interface was studied.Microstructures and electrochemical performance of the SSC-LSGMC5/LSGMC5/LSGMC5 assembly with an LSGMC5 interlayer synthesized at various temperatures were studied.The bonding of electrode/interlayer interface was better than that of electrode/electrolyte interface without interlayer when the sintered temperature was higher than 1 623 K,showed a larger two-phase boundary area and three-phase boundary length.The performance of prepared assembly depended on the sintering temperature of both the interlayer and the electrode.The sample assembly with an interlayer sintered at 1 673 K and an electrode sintered at 1 123 K exhibited the highest performance.Compared with the assembly with an LSGMC5 interlayer synthesized by the solid-state reaction,assembly with an LSGMC5 interlayer synthesized by the citrate method showed a reduced ohmic resistance and improved activity for oxygen reduction.福建省科技攻关计划重点项目(2003H046);; 留学回国人员基金资助项

中国页岩气发展战略对策建议

从中国页岩气资源状况、勘探开发重要进展、关键技术与装备重要突破等方面，系统总结、分析了中国页岩气发展形势，指出现阶段中国页岩气发展仍存在认识误区、页岩气资源落实程度低且经济性不确定性大、３５００ｍ以深核心勘探开发技术与装备尚未突破、勘探开发成本居高不下、多种技术因素严重制约其发展等５大挑战。针对这５大挑战，提出了促进中国页岩气进一步发展的５条建议：①制定符合中国国情及勘探开发阶段的页岩气发展战略和目标，２０２０年确保实现页岩气年产量２００×１０８ｍ３，力争实现３００×１０８　ｍ３；②重视海相低产低压页岩气成藏富集地质理论和勘探开发关键工程技术攻关，有序推动非海相页岩气勘探开发示范区建设；③国家应进一步出台政策并设立专项创新基金，支持各企业开展页岩气勘探开发相关技术与装备研发，强化３５００ｍ 以深页岩气勘探开发技术、装备、工艺体系研发，推动中国深层页岩气勘探开发突破；④持续推动中国页岩气地质理论、勘探开发技术与管理创新，强化钻井、压裂等全过程成本控制，努力实现中国页岩气经济有效规模开发；⑤改革矿权管理制度，建立页岩气勘探开发数据信息平台，正确引导非油气企业参与页岩气勘探开发