Bilayered electrolytes

In addition to bilayered anode and cathode functional layer and current collector/sup-port layer combinations, bilayered electrolyte structures are commonly fabricated, particularly for low-temperature operation below 700°C, by a variety of processing methods. Bilayered electrolytes are used for several purposes ... 

The results summarized here illustrate the importance of identifying a processing method that produces not only the targeted high density and low thickness for each electrolyte layer, but which is also compatible with the combination of materials used in a bilayer electrolyte to avoid inter-reactions between the layers. 

PLD has also been utilized to produce bilayer electrolytes. In one study, aNiO-YSZ (anode support, tape cast)/NiO-SDC (AFL, screen-printed)/ScSZ-SDC (electrolyte bilayer, PLD)/SSC (cathode, screen-printed) cell showed excellent performance (0.5 and 0.9 W/cm2 at 550 and 600°C, respectively), with an OCV of 1.04 V at 600°C, indicating that the PLD technique was successful in depositing a sufficiently dense ScSZ electronic blocking layer to suppress electronic conduction normally observed across single-layer SDC electrolytes, and which typically result in lower OCV values (0.87 V, 600°C) [46, 127],... 

Bi Z, Yi B, Wang Z, Dong Y, Wu H, She Y et al. A high-performance anode-supported SOFC with LDC-LSGM bilayer electrolytes. Electrochem. Solid State Lett. 2004 7 A105-A107. 

The interfaces dielectric-electrolyte are less important in classical electrochemistry, but are central for bioelectrochemistry and colloid science. These are, e.g., ionic crystal-electrolyte, lipid-bilayer-electrolyte, and protein-electrolyte interfaces. Such interfaces are not chargeable, but they may contain charges attached to surfaces. All these interfaces, chargeable or containing fixed charges, zwitter-ions or dipoles, are called electrified interfaces. 

A lamellar lyotropic phase, essentially a stack of lipid bilayers, is a nano-heterogeneous medium and any attempt to comprehend its flexoelectricity in terms of bulk polarization and a bulk flexocoefficient would run into problems. The flexoelectric effect of the lamellar phase can most easily be described by summing up the flexovoltages of all consecutive curved bilayers that are connected in series by the inter bilayer electrolyte. 

S. Chan, X. Chen, and K. Khor. A simple bilayer electrolyte model for solid oxide... 

Tsai, T., Perry, E., and Barnett, S. (1997). Low-temperature solid-oxide fuel cells utilizing thin bilayer electrolytes./ Electrochem. Soc 144 L130-L132. 

Wachsman E, Jayaweera P, Jiang N, Lowe D, Pound B (1997) Stable high conductivity ceria/bismuth bilayered electrolytes. J Electrochem Soc 144 233-236... 

Liu, Q.L., Khor, KA., Chan, SXI., and Chen, X.J. (2006) Anode-supported solid oxide fuel cell with yttria-stabilized zirconia/gadolinia-doped ceria bilayer electrolyte prepared by wet ceramic cosintering process. J. Power Sources,... 

Ahn, J.S., Pergolesi, D., Camaratta, M.A. et al. (2009) High-performance bilayered electrolyte intermediate temperature solid oxide fuel cells. Electrochem. Commun.,... 

Tsai et al. (1997) reported building soUd-oxide fuel cells with an electrolyte of yttrium-doped ceria that was 4 to 8 p,m thick. A thin layer (1 to 1.5 p,m) of a second electrolyte, of the YSZ type, was deposited between the electrolyte and the anode to eliminate the influence of electronic conductivity of the electrolyte. A cell having this bilayer electrolyte had an OCV of 98% of the theoretical EMF, which shows that there is no effect of the electronic component of conduction (without the second YSZ electrolyte, the OCV was only 50% of the theoretical value). At 600°C the electrolyte had a resistivity of 0.25 cm. At a current density of 400 mA/cm, the cell voltage was 0.4 V. The maximum energy density was 210 mW/cm. At 550°C, the resistivity of the electrolyte was 0.45 cm ... 

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