Yi-Mei Yin

Novel Nano-composites SDC–LiNaSO4 as Functional Layer for ITSOFC

As an ionic conductive functional layer of intermediate temperature solid oxide fuel cells (ITSOFC), samarium-doped ceria (SDC)–LiNaSO4 nano-composites were synthesized by a sol–gel method and their properties were investigated. It was found that the content of LiNaSO4 strongly affected the crystal phase, defect concentration, and conductivity of the composites. When the content of LiNaSO4 was 20xa0wt%, the highest conductivity of the composite was found to be, respectively, 0.22, 0.26, and 0.35 S cm−1 at temperatures of 550, 600, and 700xa0°C, which are much higher than those of SDC. The peak power density of the single cell using this composite as an interlayer was improved to, respectively, 0.23, 0.39, and 0.88xa0Wxa0cm−2 at 500, 600, and 700xa0°C comparing with that of the SDC-based cell. Further, the SDC–LiNaSO4(20xa0wt%)-based cell also displayed better thermal stability according to the performance measurements at 560xa0°C for 50xa0h. These results reveal that SDC–LiNaSO4 composite may be a potential good candidate as interlayer for ITSOFC due to its high ionic conductivity and thermal stability.

Novel cathode-supported hollow fibers for light weight micro-tubular solid oxide fuel cells with an active cathode functional layer

Micro-tubular SOFCs have the potential to become light-weight portable auxiliary power units for aircraft or spacecraft. In this work, a novel dual-layer ceramic hollow fiber for a cathode-supported micro-tubular solid oxide fuel cell (MT-SOFC) has been successfully developed via a co-spinning-sintering technique. The green cathode hollow fibers, in dual layer configuration, consisting of a La0.8Sr0.2MnO3−δ (LSM) main layer and a LSM–Y2O3 stabilized ZrO2 (YSZ) functional layer with increased three phase boundary length, are first prepared by co-spinning, which are then sintered at around 1350 °C to allow the creation of sufficient mechanical strength. Other cell components like the electrolyte (YSZ) and anode (NiO + YSZ) are then coated separately. The coated electrolyte film with a thickness of around 27 μm is obtained by co-sintering of YSZ/LSM–YSZ/LSM in a sandwich structure. The porous LSM substrate functions as an oxygen-supplying and current collecting layer. The prepared MT-SOFC, tested with hydrogen as the fuel and air as the oxidant, delivers a maximum power density of up to 475 mW cm−2 at 850 °C, which is much higher than that of a similar cell without a cathode functional layer.

Preparation and Performance of SrCo1-xGaxO3-δ Cathode Materials for Interme-diate Temperature Solid Oxide Fuel Cells: Preparation and Performance of SrCo1-xGaxO3-δ Cathode Materials for Interme-diate Temperature Solid Oxide Fuel Cells

采用EDTA-柠檬酸联合络合法制备了SrCo 1- x Ga x O 3- δ ( x =0、0.1、0.2、0.3、0.4)系列阴极材料。通过 X 射线衍射、热膨胀测试、X 射线光电子能谱和电化学阻抗谱等方法对试样进行分析, 研究了Ga掺杂量对材料性能的影响。结果表明试样均为钙铁矿结构, 随着 Ga 含量的增加, 阴极粉体材料热膨胀系数、电导率和阴极材料表面的吸附氧逐渐减小。其中, SrCo 0.8 Ga 0.2 O 3- δ 的面电阻最小, 600℃时为 0.73 Ω•cm 2 , 以其为阴极的单电池在650℃的工作温度下的最大输出功率达 0.484 W/cm 2 。采用EDTA-柠檬酸联合络合法制备了SrCo 1- x Ga x O 3- δ ( x =0、0.1、0.2、0.3、0.4)系列阴极材料。通过 X 射线衍射、热膨胀测试、X 射线光电子能谱和电化学阻抗谱等方法对试样进行分析, 研究了Ga掺杂量对材料性能的影响。结果表明试样均为钙铁矿结构, 随着 Ga 含量的增加, 阴极粉体材料热膨胀系数、电导率和阴极材料表面的吸附氧逐渐减小。其中, SrCo 0.8 Ga 0.2 O 3- δ 的面电阻最小, 600℃时为 0.73 Ω•cm 2 , 以其为阴极的单电池在650℃的工作温度下的最大输出功率达 0.484 W/cm 2 。

Electrolyte Thickness Control and Its Effect on YSZ/Ni-YSZ Dual-layer Hollow Fibres: Electrolyte Thickness Control and Its Effect on YSZ/Ni-YSZ Dual-layer Hollow Fibres

本研究利用相转化共纺丝法一步制备出微管式固体氧化物燃料电池(MT-SOFC)用电解质/阳极(YSZ/NiO-YSZ)双层中空纤维膜, 将制得的YSZ/NiO-YSZ双层中空纤维膜前驱体经1450℃烧结后, 以纯H 2 在700℃下还原4 h得到YSZ/Ni-YSZ双层中空纤维膜。电解质YSZ膜层厚度通过改变YSZ铸膜液挤出速率来调节。将La 0.8 Sr 0.2 MnO 3- δ (LSM)阴极乳浆浸渍涂覆在烧结后的YSZ/NiO-YSZ双层中空纤维膜外, 经1200℃烧结后形成微管式固体氧化物燃料电池。结果表明, 当阳极铸膜液以10?mL/min速率挤出, 而电解质铸膜液挤出速率为0.5、1、1.5、2 mL/min时, 构造的YSZ/Ni-YSZ双层中空纤维膜电解质层厚度分别为6、13、18、28 μm, 其机械强度、气密性均随着电解质层厚度增加而增大, 但电导率与孔隙率受电解质层厚度的影响较小。YSZ膜厚度为28 μm的MT-SOFC, 800℃时以20 mL/min氢气作为燃料, 30 mL/min空气作为氧化剂, 最大开路电压为1.01 V, 最大输出功率只有75 mW/cm 2 。但同样测试条件下, YSZ膜厚度为6 μm的MT-SOFC, 开路电压为0.92 V, 最大输出功率升至329 mW/cm 2 。本研究利用相转化共纺丝法一步制备出微管式固体氧化物燃料电池(MT-SOFC)用电解质/阳极(YSZ/NiO-YSZ)双层中空纤维膜, 将制得的YSZ/NiO-YSZ双层中空纤维膜前驱体经1450℃烧结后, 以纯H 2 在700℃下还原4 h得到YSZ/Ni-YSZ双层中空纤维膜。电解质YSZ膜层厚度通过改变YSZ铸膜液挤出速率来调节。将La 0.8 Sr 0.2 MnO 3- δ (LSM)阴极乳浆浸渍涂覆在烧结后的YSZ/NiO-YSZ双层中空纤维膜外, 经1200℃烧结后形成微管式固体氧化物燃料电池。结果表明, 当阳极铸膜液以10?mL/min速率挤出, 而电解质铸膜液挤出速率为0.5、1、1.5、2 mL/min时, 构造的YSZ/Ni-YSZ双层中空纤维膜电解质层厚度分别为6、13、18、28 μm, 其机械强度、气密性均随着电解质层厚度增加而增大, 但电导率与孔隙率受电解质层厚度的影响较小。YSZ膜厚度为28 μm的MT-SOFC, 800℃时以20 mL/min氢气作为燃料, 30 mL/min空气作为氧化剂, 最大开路电压为1.01 V, 最大输出功率只有75 mW/cm 2 。但同样测试条件下, YSZ膜厚度为6 μm的MT-SOFC, 开路电压为0.92 V, 最大输出功率升至329 mW/cm 2 。