中温复合固体电解质SDC-LSGM的制备和性能

采用甘氨酸-硝酸盐法分别制备了Ce0.85Sm0.15O2-δ(SDC)与La0.9Sr0.1Ga0.8Mg0.2O3-δ(LSGM)两种电解质材料, 并用固相混合法将两种材料按不同质量比(SDC与LSGM的质量比分别为9∶1, 8∶2, 5∶5)混合制备复合电解质材料. 采用交流阻抗技术对样品的电学性能进行研究. 实验结果表明, SDC与LSGM的质量比为9∶1(SL91)时, 样品具有较高的电导率, 在350—800 ℃温度范围内其电导率均比SDC的高. 以复合电解质为支撑体, 以Sm0.5Sr0.5CoO3 为阴极、NiO/SDC 为阳极制成单电池, 测试结果显示, 在800 ℃时以SL91为电解质的单电池的最大输出功率密度为0.25 W/cm2, 最大电流密度为1.06 A/cm2. 在电池的工作温度区间(600—800 ℃)内以复合材料为电解质的单电池的开路电压比以SDC为电解质的高.     

高性能镓酸镧基电解质燃料电池

制备并用多种电化学方法研究了LaGaO3基高性能中温固体氧化物燃料电池的电极和电解质材料，组装出了高性能单电池.实验发现， Co掺杂的La0.8Sr0.2Ga0.8Mg0.2O3电解质中， Co含量的增加显著提高了电解质的氧离子电导率，电解质的氧迁移数略有减小，是非常好的中、低温燃料电池电解质.钴掺杂的电解质不仅显著减小了电池的欧姆电阻，而且减小了电池的阴、阳极极化过电位.以La0.8Sr0.2Ga0.8Mg0.11Co0.09O3为电解质时电池在1073、973、873 K下的最大输出功率密度分别达到1.77、0.92、0.41 W•cm－2，是非常有前景的电池体系.     

LaGaO3基固体氧化物燃料电池阳极材料Ce1-xTmxO2-δ（Tm=Cu,Mn,Fe）研究

以研究与Sr,Mg掺杂LaGaO3(LSGM)电解质匹配的阳极材料为出发点,系统研究了Ce1-xTmxO2-δ(Tm=Cu,Mn,Fe)固溶体的晶体结构、热化学稳定性、电化学性能和单电池发电实验。柠檬酸法合成的Ce1-xTmxO2-δ化合物在x<0.2时均为单相材料,与LSGM电解质有良好的热化学相容性。采用交流阻抗法研究了阳极材料的电化学性能,金属元素掺杂可以显著地改善CeO2电化学性能,Fe元素掺杂阳极材料极化电阻最小,随着元素掺杂量的增加以及氢气增湿,极化电阻减小。采用电解质支撑结构单电池进行发电实验,在800℃时,以Ce0.8Fe0.2O2-δ作为阳极的单电池最高功率密度可达98 mW.cm-2,表明该材料作为IT-SOFC的阳极材料具有一定的可行性,有望成为适合LSGM电解质的阳极材料。     

二甲醚的电催化氧化反应

 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H2O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／La0．9Sr0．1Ga0．8Mg0．2O3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H2O．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－Mg0．11Co0．09O3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．     

Preparation and Electrochemical Performance of Cobalt-free Cathode Material Ba0.5Sr0.5Fe0.9Nb0.1O3-δ for Intermediate-temperature Solid Oxide Fuel Cells

Perovskite oxide Ba0.5Sr0.5Fe0.9Nb0.1O3-δ（BSFN） as a cobalt-free cathode for intermediate-temperature solid oxide fuel cells（IT-SOFCs） on the Ce0.5Sm0.2O1.9（SDC） and La0.9Sr0.1Ga0.8Mg0.23O3-δ（LSGM） electrolytes was prepared and investigated. The single phase BSFN oxide with a cubic perovskite structure and relatively high elec- trical conductivities was obtained after sintering at 1250℃ for 10 h in air. The BSFN cathode exhibited excellent chemical stability on the SDC and LSGM electrolytes at temperatures below 950 ℃. The area specific resistance of the BSFN cathode on the SDC and LSGM electrolytes were 0.024 and 0.021 Ω·cm2 at 800℃, respectively. The maximum power densities of the single cell with BSFN cathode in 300 μm-thick SDC and LSGM electrolytes achieved 414 and 516 mW/cm2 at 800℃, respectively. These results show that the BSFN material is a promising co- bait-free cathode candidate to be used in IT-SOFCs. A combination of the BSFN cathode and LSGM electrolyte is preferred owing to its excellent electrochemical performance.     

天然气和甲烷固体氧化物燃料电池中的Ni-LCCM-GDC阳极性能研究

采用溶胶-凝胶法合成了纳米粉体La_1-xCe_xCr_0.5Mn_0.5O_3-δ(x=0.05,0.10,0.15,0.20)(LCCM),并采用共压-共烧结法制备了以复合阳极Ni-La_0.9Ce_0.1Cr_0.5Mn_0.5O_3-δ-Ce_0.8Gd_0.2O_2-δ(GDC)为支撑、GDC为电解质、La_0.8Sr_0.2Co_0.8Fe_0.2O_3-δ(LSCF)-GDC为复合阴极的单电池。利用XRD和SEM等方法对阳极材料进行了晶相结构、化学相容性、微观形貌分析。在500~750 ℃范围内,分别以湿天然气(3% H₂O)和甲烷为燃料气,氧气为氧化气测试了单电池的电化学性能,同时检测了以甲烷为燃料气的阳极尾气组成。结果表明：复合阳极材料具有良好的化学相容性;阳极和阴极具有较好的孔隙结构。以天然气和甲烷为燃料气的单电池在700 ℃时最大电流密度分别为131.96 mA·cm^-2,162.36 mA·cm^-2; 最大比功率分别为28.61 mW·cm^-2,31.03 mW·cm^-2。在500~750 ℃范围内阳极尾气中均检测出CO,CO₂,在700 ℃时CO,CO₂含量达到最大值,分别为2.39254%,6.20891%。     

Solid oxide fuel cells with both high voltage and power output by utilizing beneficial interfacial reaction

An intriguing cell concept by applying proton-conducting oxide as the ionic conducting phase in the anode and taking advantage of beneficial interfacial reaction between anode and electrolyte is proposed to successfully achieve both high open circuit voltage (OCV) and power output for SOFCs with thin-film samarium doped ceria (SDC) electrolyte at temperatures higher than 600 °C. The fuel cells were fabricated by conventional route without introducing an additional processing step. A very thin and dense interfacial layer (2-3 μm) with compositional gradient was created by in situ reaction between anode and electrolyte although the anode substrate had high surface roughness (>5 μm), which is, however, beneficial for increasing triple phase boundaries where electrode reactions happen. A fuel cell with Ni-BaZr(0.4)Ce(0.4)Y(0.2)O(3) anode, thin-film SDC electrolyte and Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) (BSCF) cathode has an OCV as high as 1.022 V and delivered a power density of 462 mW cm(-2) at 0.7 V at 600 °C. It greatly promises an intriguing fuel cell concept for efficient power generation.     

La0.8Sr0.2Ga0.8Mg0.2O2.8的电化学性质及其在SOFC中的应用

采用凝胶浇注法制备具有较高氧离子电导率的固体电解质La0.8Sr0.2Ga0.8Mg0.2O2.8粉料.X射线衍射结果表明,于1400℃焙烧后即形成了钙钛矿结构,无杂相存在.探讨了粉料压制坯体的致密化和导电性能在1450℃下与烧结时间的关系,发现烧结时间为18h时其相对密度达98.3%,而在24h的情况下,样品具有最佳的氧离子导电性.采用Ni-Ce0.8Gd0.2O1.9作为阳极,La0.8Sr0.2Ga0.6Ni0.4O2.7作为阴极,组装了平板型固体氧化物燃料电池(SOFC).阳极和阴极分别通入含3%H2O的氢气和空气,750℃时的开路电压为1.04V,最大输出功率密度(P)达252mW/cm2(U=0.48V,J=525mA/cm2).     

Ba0.97Ce0.8Ho0.2O3-α陶瓷的离子导电性及其燃料电池性能

The perovskite-type-oxide solid solution Ba0.97Ce0.8Ho0.2O3-α was prepared by high temperature solidstate reaction and its single-phase character was confirmed by X-ray diffraction. The ionic conduction of the sample was investigated using electrical methods at elevated temperatures, and the performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured, which were compared with those of BaCe0.8Ho0.2O3 - α. In wet hydrogen, BaCe0.8 Ho0.2 O3 - α almost exhibits pure protonic conduction at 600-1000 ℃, and its protonic transport number is 1 at 600-900 ℃ and 0.99 at 1000 ℃. Similarly,Ba0.97Ce0.8Ho0.2O3-α exhibits pure protonic conduction with the protonic transport number of 1 at 600-700 ℃, but its protonic conduction is slightly lower than that of BaCe0.8Ho0.2O3-α, and the protonic transport number are 0.99-0.96 at 800-1000 ℃. In wet air, the two samples both show low protonic and oxide ionic conduction. For Ba0.97Ce0.8Ho0.2O3-α, the protonic and oxide ionic transport numbers are 0.01-0.11 and 0.30-0.31 respectively, and for BaCe0.8Ho0.2O3-α, 0.01-0.09 and 0.27-0.33 respectively. Ionic conductivities of Ba0.97Ce0.8Ho0.2O3-α are higher than those of BaCe0.8Ho0.2O3-α under wet hydrogen and wet air. The performance of the fuel cell using Ba0.97Ce0.8Ho0.2O3-α as solid electrolyte is better than that of BaCe0.8Ho0.2O3-α. At 1000 ℃, its maximum short-circuit current density and power output density are 465 mA/cm2 and 112 mW/cm2, respectively.     

利用钐掺杂的氧化铈夹层提高燃料电池阳极的活性

考察了Ni-钐掺杂的氧化铈(Ni-SDC)复合阳极与La0.9Sr0.1Ga0.8Mg0.2O3(LSGM)电解质中间加入的SDC 中间层对阳极及整个电池性能的影响.结果表明，SDC中间层的加入显著减小了阳极极化过电位，但同时引入了欧姆降，降低了电池的功率输出密度.氢在Ni-SDC电极的氧化主要由两个过程控制，分别对应于交流阻抗谱的两个阻抗半圆，高频环随着SDC中间层的加入显著减小，可能对应于H2在Ni-SDC/SDC/H2三相界的电化学氧化或氧从LSGM向SDC的传输，低频环与SDC中间层无关，可能对应于氢在电极表面的解离吸附及吸附物种的扩散过程.使用Ni-SDC/SDC夹层阳极可以明显地提高电池的稳定性.     

La0.8Sr0.2Ga0.8Mg0.2O3与La0.8Sr0.2Ga0.8Mg0.15Co0.05O3电导的对比

采用固相合成法制备了La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282)和La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5), 利用四电极交流阻抗法和Hebb-Wagner 极化法对比研究了两种材料的总电导率和电子电导率. 实验结果表明, LSGM8282 的总电导率与氧分压无明显依赖关系, 而LSGMC5 的总电导率在高氧分压区随氧分压降低而增加,在中等氧分压区域基本保持不变. 在973-1173 K的温度范围内, LSGM8282的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和1/4.在1073-1173 K的温度范围内, LSGMC5的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和约为1/8, 表明LSGMC5的空穴产生机制可能与LSGM8282不同. LSGM8282 的氧离子电导率与氧分压无关, 而LSGMC5 的氧离子电导率在高氧分压区随氧分压的减小而增加.     

高温固体氧化物电解池钙钛矿型氧电极材料Ba_xSr_(1-x)Co_(0.8)Fe_(0.2)O_(3-δ)结构计算与性能研究

研究和开发高性能的钙钛矿型混合电导氧化物是目前高温固体氧化物电解池(SOEC)氧电极材料研究的热点.选择BaxSr1-xCo0.8Fe0.2O3-δ系列材料,通过对材料的容差因子、关口半径、晶格自由体积等计算,以及对平均键能、B位离子的变价能力、催化活性等方面的分析,确定了A位最佳配比.对优化出的Ba0.5Sr0.5Co0.8Fe0.2O3-δ材料的电化学性能进行了研究,并与自制的La0.2Sr0.8MnO3(LSM)氧电极材料进行了比较.结果表明:850℃下阳极极化阻抗(ASR)仅为0.07Ωcm2,远低于LSM;将其应用于SOEC氧电极进行高温电解制氢试验,产氢速率为相同条件下LSM的2.3倍,说明将Ba0.5Sr0.5Co0.8Fe0.2O3-δ用作SOEC阳极材料具有很好的应用前景.     

Gd_(0.2)Ce_(0.8)O_2包覆固体氧化物燃料电池Ni-ScSZ复合阳极制备及性能表征

应用双层流延法制备Ni-ScSZ阳极支撑体-ScSZ电解质复合膜素坯,经共烧结得到复合膜.以硝酸铈和硝酸钆为原料,柠檬酸作燃料,由燃烧合成法制备Gd0.2Ce0.8O2(GDC)包覆的Ni-ScSZ阳极.X-射线衍射(XRD)和电子显微镜(TEM和SEM)分析显示,Ni-ScSZ阳极颗粒表面的包覆层是由直径小于100 nm的GDC微粒构成,并与Ni-ScSZ阳极颗粒紧密烧结在一起.实验表明,2.0%(by mass)GDC包覆的Ni-ScSZ阳极具有较佳的性能,以其组装的单电池在850℃用H2或CH4作燃料的最大功率密度分别是825和848 mW/cm2,而由无包覆的Ni-ScSZ作阳极的单电池,功率密度分别是584和586 mW/cm2.由两种阳极材料组装的单电池,分别在700℃于CH4气氛下作长时间发电实验,发现2.0%(by mass)GDC包覆的Ni-ScSZ阳极比Ni-ScSZ阳极具有较好的抗碳沉积性能.     

SDC和SSC在低温常压电化学合成氨中的性能研究

用溶胶—凝胶法制备了Ce0.8Sm0.2O2-δ(SDC)和Sm0.5Sr0.5CoO 3-δ（SSC）超细粉体,采用XRD、TEM和SEM等对粉体进行了观察和表征。分别以Ni-SDC和SSC为阴极, 磺化聚砜质子交换膜为电解质, Ni- SDC金属陶瓷为阳极,银-铂网做集流体组成单电池,在25℃～120℃温度范围内研究了其电导率随温度变化关系及在电化学合成氨中的性能。结果表明：在25℃～120℃温度范围内,使用Ni-SDC和SSC为阴极均有氨气生成,而SSC对电化学合成氨的性能优于Ni-SDC, 在80℃时氨产率达到了6.5×10-9 mol•s-1•cm-2。     

High performance anode-supported intermediate temperature solid oxide fuel cells (IT-SOFCs) with La0.8Sr0.2Ga0.8Mg0.2O3−δ electrolyte films prepared by electrophoretic deposition

Remarkable power density was obtained for anode-supported solid oxide fuel cells (SOFCs) based on La_0.8Sr_0.2Ga_0.8Mg_0.2O_3−δ (LSGM) electrolyte films, fabricated following an original procedure that allowed avoiding undesired reactions between LSGM and electrode materials, especially Ni. Electrophoretic deposition (EPD) was used for the fabrication of 30 μm-thick electrolyte films. Anode supports were made of La_0.4Ce_0.6O_2−x (LDC). The LSGM powder was deposited by EPD on an LDC green tape-cast membrane added with carbon powder, both as pore former and substrate conductivity booster. A subsequent co-firing step at 1490 °C produced dense electrolyte films on porous LDC skeletons. Then, a La_0.8Sr_0.2Fe_0.8Co_0.2O_3−δ (LSFC) cathode was applied by slurry-coating and calcined at 1100 °C. Finally, the porous LDC layer was impregnated with molten Ni nitrate to obtain, after calcination at 900 °C, a composite NiO–LDC anode. Maximum power densities of 780, 450, 275, 175, and 100 mW/cm² at 700, 650, 600, 550, and 500 °C, respectively, were obtained using H₂ as fuel and air as oxidant, demonstrating the success of the processing strategy. As a comparison, electrolyte-supported SOFCs made of the same materials were tested, showing a maximum power density of 150 mW/cm² at 700 °C, more than 5 times smaller than the anode-supported counterpart.     

中温平板型固体氧化物燃料电池研究

采用流延法制备Ni/YSZ阳极支撑体 YSZ电解质复合膜素坯.经等静压,共烧结而得到的复合膜,其YSZ电解质层的厚度在1530μm之间,面积大于100cm2.再将由柠檬酸盐法合成的Ce0.8Sm0.2O1.9(CSO)和固相法合成的La0.6Sr0.4CoO3(LSCO)相继沉积到YSZ膜上形成有CSO中间层的复合阴极,从而构成Ni/YSZ/CSO/LSCO的中温平板型固体氧化物燃料(单体)电池,其中Ni/YSZ为阳极,CSO是中间层,LSCO为阴极.以H2作燃料气,O2为氧化气,850℃下,该单电池开路电压达1.1V,最大输出功率密度0.2W/cm2.本文还对该单电池复数阻抗谱进行了分析讨论.     

Cu-CeO2基阳极直接甲烷SOFC的制备及其性能

采用干压法制备了NiO-YSZ(氧化钇稳定氧化锆)/(ZrO2)0.89(Sc2O3)0.1(CeO2)0.01(10ScSZ-1CeO2)半电池, 经还原-酸溶法除去NiO制备了多孔YSZ负载致密10ScSZ-1CeO2双层结构, 通过浸渍法在多孔YSZ阳极基体中引入Ce、Cu的硝酸盐制备Cu-CeO2-YSZ复合阳极, 结合La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极构建了Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF单元电池. 通过X射线衍射(XRD)和场发射扫描电镜(FESEM)等手段对电池单元的物相、微观结构进行表征. 结果表明: 还原-酸溶法制备的YSZ/10ScSZ-1CeO2双层结构的YSZ基体具有孔隙率高(>64%)、孔洞连通性好的微观结构, 有助于采用浸渍法引入Ce、Cu硝酸盐; 10ScSZ-1CeO2电解质薄膜致密无缺陷, 厚约30 μm. 电性能测试表明所构建单元固体氧化物燃料电池(SOFC)具有良好的电性能输出, 在650 ℃以湿H2和CH4为燃料时的最大功率密度分别为0.29和0.09 W·cm-2; 在700 ℃以湿H2和CH4为燃料时的最大功率密度分别达到0.48 和0.21 W·cm-2. 优良的电性能主要归功于小的电解质内阻和阴极极化电阻以及良好的阳极微观结构.     

Improved sintering and electrical properties of La-doped CeO<Subscript>2</Subscript> buffer layer for intermediate temperature solid oxide fuel cells using doped LaGaO<Subscript>3</Subscript> film prepared by screen printing process

Effects of a sintering agent for La-doped ceria (LDC) as a buffer layer to prevent a chemical reaction between Ni in anode and Sr- and Mg-doped lanthanum gallate (LSGM) electrolyte during sintering were studied for improving sintering and electrical properties. Electrochemical performance of anode-supported solid oxide fuel cells (SOFCs) using LDC and LSGM films prepared by screen printing and co-sintering (1,350 °C) was also investigated. The prepared cell with dense LDC (ca. 17 μm) and LSGM electrolyte (ca. 60 μm) films showed an open circuit voltage close to the theoretical value of 1.10 V and a high maximum power density (0.831 W cm^–2) at 700 °C. The addition of 1 wt.% LSGM to porous LDC buffer layer was effective for improving the sintering density and electrical conductivity, resulting in the high power density due to the decreased internal resistance loss.     

Ce1-xGdxO2-x/2的溶胶-凝胶法合成及其性质

利用溶胶-凝胶法合成了Ce₁-xGdxO_2-x/2(x=0.1～0.6)系列固体电解质,系统地研究了其结构、热膨胀系数和导电性.XRD结果表明,160℃即完全形成立方萤石结构.由于溶胶-凝胶法合成的物质粒度均匀,颗粒小,故在较低温度(1300℃)时即可形成高致密样品,此温度明显低于传统的高温固相法烧结温度(1600～1650℃).高温X射线衍射测得Ce_0.8Gd_0.2O_1.9的热膨胀系数为8.125×10^-6K₁.阻抗谱表明,溶胶-凝胶法合成可减少或消除固体电解质的晶界电阻,600℃时Ce_0.8Gd_0.2O_1.9的电导率为5.26×10^-3S/cm,活化能E_a=0.82eV.     

镓酸镧基中温-SOFC的新型阳极NiO-La0.3Ce0.7O2-δ研究

采用共沉淀法制备了NiO-La0.3Ce0.7O2-δ(LDC30)新型阳极材料, 通过对其配方与性能的研究, 探索获得中温SOFC高性能阳极材料的新途径.