A high temperature reduction cleaning (HTRC) process: a novel method for conductivity recovery of yttrium-doped barium zirconate electrolytes
A high temperature reduction cleaning (HTRC) process: a novel method for conductivity recovery of yttrium-doped barium zirconate electrolytes
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DOI：
10.1039/c6ta03552c
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发表时间：
2016-07
影响因子：
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通讯作者：
Donglin Han;J. Iihara;S. Uemura;Kenji Kazumi;Chihiro Hiraiwa;M. Majima;T. Uda
中科院分区：
文献类型：
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作者：
Donglin Han;J. Iihara;S. Uemura;Kenji Kazumi;Chihiro Hiraiwa;M. Majima;T. Uda
质子导电掺y的BaZrO3 （BZY）和氧化镍（NiO）分别是目前质子陶瓷燃料电池最有前途的电解质和阳极催化剂。然而，在共烧结制造燃料电池的过程中，Ni阳离子从阳极扩散到BZY电解质的晶格中，导致电解质电导率和燃料电池性能的显著下降。为了解决这一问题，在这项工作中，我们报告了一种新的方法，称为高温还原清洗（htc）工艺，它由几个顺序的热处理组成。最有趣的一点是，在ti脱氧的Ar气氛中，在1400℃下对nio污染的BZY进行热处理100 h后，观察到Ni阳离子从BZY晶格中排出，并在晶界处以Ni金属颗粒的形式分离。BZY电解质的电导率得到了恢复。然而，当分离的Ni金属颗粒在氧气气氛中氧化成NiO颗粒时，BZY电解液沿晶界出现了分层现象。为了解决这一问题，设计了一系列顺序热处理。
Proton conducting Y-doped BaZrO3 (BZY) and nickel oxide (NiO) are currently the most promising electrolyte and anode catalyst for protonic ceramic fuel cells, respectively. However, during the co-sintering process to fabricate the fuel cells, Ni cations diffuse from the anode into the lattice of the BZY electrolyte, resulting in significant degradation of the electrolyte conductivity and fuel cell performance. With the aim to solve such a problem, in this work, we report a novel method, named as high temperature reduction cleaning (HTRC) process, which is composed of several sequential heat-treatments in controlled atmospheres. The most interesting point is that after heat-treating the NiO-contaminated BZY at 1400 °C in a Ti-deoxidized Ar atmosphere for 100 h, Ni cations were observed to be expulsed from the BZY lattice and segregated at the grain boundary as Ni metal particles. And the conductivity of the BZY electrolyte was recovered. However, delamination along the grain boundary of the BZY electrolyte was introduced when the segregated Ni metal particles were oxidized to NiO particles in an oxygen atmosphere. And a series of sequential heat-treatments were designed to solve such a problem.