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Ionomigration of Neutral Phases in Ionic Conductors
Author(s) -
Chen I.Wei,
Kim SeungWan,
Li Ju,
Kang SukJoong L.,
Huang Fuqiang
Publication year - 2012
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201200011
Subject(s) - materials science , electrolyte , yttria stabilized zirconia , electrolysis , ionic bonding , thermal diffusivity , fast ion conductor , electrochemistry , ion , chemical physics , sintering , diffusion , conductor , cubic zirconia , electrode , chemical engineering , ceramic , composite material , thermodynamics , chemistry , physics , engineering , quantum mechanics
Without sensing any physical force, a neutral object in an ion conducting solid can move in a uniform electrochemical field by coupling a global ion wind with localized counterion diffusion at the interface. This happens to pores and gas bubbles at 840 °C in a fast O 2− conductor, yttria‐stabilized zirconia (YSZ), despite having cations that are essentially frozen with lattice diffusivities 10 12 times slower than the O 2− diffusivity. Through‐thickness migration and massive electro‐sintering in thin YSZ ceramics are observed at voltages similar to those in YSZ fuel cells and electrolysis cells. This effect should apply to any electrochemically‐loaded multiphase ionic conducting solid, with or without an electric field, and can lead to electrolyte sintering, phase accumulation and electrode debonding, resulting in unexpected benefit or damage in electrochemical devices. As the velocity obeys a pseudo Stokes‐Einstein equation, inversely proportional to the object size, an especially enhanced size effect is expected in nanocomposites.