NaCl对BaZr_(0.63)Ce_(0.27)Y_(0.10)O_(2.95)/ZnO质子导体的烧结性与电化学性能的影响

Effect of NaCl on Sinterability and Electrochemical Performance of BaZr_(0.63)Ce_(0.27)Y_(0.10)O_(2.95)/ZnO Protonic Conductors

采用机械混合和高温固相反应法，在2％（摩尔分数）ZnO掺杂BaZr063Ce0.27Y0.10O2.95的质子导体（BZCY-Z2）中添加0～15％（摩尔分数）NaCl，在1400℃保温4h，制备BaZr0．63Ceo-27Y0100295／ZnO／NaCl（BZCY-Z2．Cl）复相质子导体。结果显示，加入NaCl作为复相烧结助剂后，由于出现液相，降低了试样的烧结温度与保温时间，从而改善了试样的烧结性能；NaCl均匀分布于晶界，改善了晶界特性，提高了晶界质子导电性，质子导体于700℃时在湿氢气氛中总电导率达7．48×100S／cm电解质支撑型单元电池测试结果表明，单电池在550、600、650和700℃下离子传导系数分别达到0．97、0．97、0．95和0．93，表明该电解层材料为良好的质子导体；700℃时功率密度为17mW／cm2，由于电解层厚度较厚（0．9nm），导致输出功率相对较低。上述结果表明所制备的质子导体材料具有良好的电化学性能。

The BaZr0.63Ce0.27Y0.1002.95/ZnO/NaC1 （BZCY-Z2-C1） proton conductors with the heterogeneous structure were synthe- sized with NaC1 of 5%, 10% and 15% （in mole fraction） to ZnO of 2% doped BaZr0.63Ceo.27Yo.1002.95 proton conductors （i.e., BZCY-Z2） through a mechanical-mixing process and sintering at 1 400 ℃ for 4 h. The results Show that the sintering temperature and soaking time can be reduced due to the presence of liquid phase after the addition of NaC1 added as a sintering aid. Therefore, the sintering properties of the BZCY-Z2-C1 proton conductor are improved by the addition of NaC1. NaC1 is homogeneously distributed on the grain boundary, changing the characteristics of grain boundary. As a result, the protonic conduction along the grain boundary is enhanced. The total conductivity of the protouic conductor reaches 7.48 x 10-3 S/cm at 700 ℃ in wet hydrogen. The experimental results of a single fuel cell with electrolyte-supported configuration reveal that the ionic transport number is 0.97, 0.97, 0.95 and 0.93 at 550, 600, 650 and 700 ℃, respectively, revealing that it is a superior protonic conductor. It also deliveries a maximum output power density of 17 mW/cm2 at 700 ℃. The lower output power density is due to a thick electrolyte （0.9 mm in thickness）. These indicate that the superior electrochemical performance of the NaCl-modified protonic conductor could be obtained.