Leland Stanford Junior University

Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Yong-Il Park

Yuji Saito

Friedrich B Prinz

Suk-Won Cha

Ali Farvid

Ryan Patrick O'Hayre

Fritz B Prinz

Sangkyun Kang

Pei-Chen Su

Sang-Joon John Lee

An improved two-step replication process for fabrication of porous metallic membranes is provided. A negative of a porous non-metallic template is made by infiltration of a liquid precursor into the template, curing the precursor to form a solid negative, and removing the template to expose the negative. Metal is deposited to surround the exposed negative. Removal of the negative provides a porous metallic membrane having pores which replicate the pores of the original template membrane. The negative is kept immersed in a liquid at all times between removing the template and depositing the metal. This immersion eliminates damage to the negative that would be incurred in drying the negative out between these processing steps. Another aspect of the invention is metallic membranes prepared according to the preceding method. For example, metallic membranes having pores smaller on one side than on the other side of the membrane are provided.

Gas/ion species selective membrane support by multi-stage nano-hole array metal structure

Dislocations are fabricated into electrolyte membrane films to increase ion conductivity. Ion and/or electron irradiation causes the growth of vacancy clusters within the thin film and collapsing into Frank dislocation loops that exhibit high ion conductivity. Maximum ion conductivity is accomplished by spatially reorienting the Frank dislocation loops during a following heat-treatment of the membrane. Thereby the dislocation loops form surface-to-surface continuous dislocations along which ions may propagate between membrane surfaces with minimal activation energies. Dislocation densities in the range of 10&#x2dc;10cm/cmmay be fabricated with conventional irradiation techniques into ceramics such as, for example yttria stabilized zirconia and doped ceria.

Solid oxide electrolyte with ion conductivity enhancement by dislocation

A fluid impermeable thin film is fabricated on a porous substrate by depositing a material having a certain spatial oxidation expansion. After deposition, the material is oxidized whereby the deposited material expands and forms a void free film on top of the porous substrate. The snuggly contacting grain boundaries of the void free film may recombine to a continuous thin film that has a thickness of only a fraction of 1 &#x3bc;m and is substantially fluid impermeable. The small film height contributes to a high ionic conductivity that makes the thin film a preferred choice for a fuel cell electrolyte membrane enabling efficient fuel cell operation at temperatures well below 500&#xb0; C.

Sub-micron electrolyte thin film on nano-porous substrate by oxidation of metal film

Gas/ion species selective membrane supported by multi-stage nano-hole array metal structure

Growing community of inventors

Kyungbuk, South Korea

Yong-Il Park