Electrochemically Scavenging the Silica Impurities at the Ni-YSZ Triple Phase Boundary of Solid Oxide Cells

Youkun Tao, Jing Shao, Shiyang Cheng

Research output: Contribution to journalLetterpeer-review

Abstract

Silica impurity originated from the sealing or raw materials of the solid oxide cells (SOCs) accumulating at the. Ni-YSZ triple phase boundaries (TPBs) is known as one major reason for electrode passivation. Here we report nanosilica precipitates inside Ni grains instead of blocking the TPBs when operating the SOCs at vertical bar i vertical bar >= 1.5 A cm-2 for electrolysis of H2O/CO2. An electrochemical scavenging mechanism was proposed to explain this unique behavior: the removal of silica proceeded through the reduction of the silica to Si under strong cathodic polarization, followed by bulk diffusion of Si into Ni and reoxidation of Si in the Ni grain.
Original languageEnglish
JournalA C S Applied Materials and Interfaces
Volume8
Issue number27
Pages (from-to)17023-17027
Number of pages5
ISSN1944-8244
DOIs
Publication statusPublished - 2016

Keywords

  • Solid oxide cells
  • Triple phase boundary
  • Silica
  • Nickel-yttria-stabilized zirconia
  • Cathodic polarization
  • Precipitation

Fingerprint Dive into the research topics of 'Electrochemically Scavenging the Silica Impurities at the Ni-YSZ Triple Phase Boundary of Solid Oxide Cells'. Together they form a unique fingerprint.

Cite this