Flash-sintering of Co2MnO4 spinel for solid oxide fuel cell applications

✍ Scribed by Andre L.G. Prette; Marco Cologna; Vincenzo Sglavo; Rishi Raj

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 830 KB
• Volume: 196
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2010.10.036

✦ Synopsis

We show that cobalt manganese oxide (Co 2 MnO 4 ) spinel can be sintered (without the application of external pressure) in a few seconds at about ∼325 • C by applying a DC electrical field of 12.5 V cm -1 , by a process known as flash-sintering. A transition from normal to flash-sintering occurs when the field is ≥7.5 V cm -1 . The flash sintering phenomenon has also been observed in yttria-stabilized zirconia (3YSZ). Together, the results for 3YSZ and Co 2 MnO 4 point towards the generality of the process, since 3YSZ is an ionic conductor while the spinel is a predominantly electronic conductor. The Co 2 MnO 4 spinels are used to protect metals, such as stainless steels, in solid oxide fuel cells. The low temperatures employed in flash sintering can obviate interfacial interdiffusion with the metal substrate; in nominal sintering these interfacial reactions can produce deleterious interfacial phases.