University of California

Polyplus Battery Company, Inc.

Other

Lutgard C DeJonghe

Steven J Visco

Craig P Jacobson

May-Ying Chu

Marca M Doeff

Yanping Ma

Yevgeniy S Nimon

Bruce D Katz

Michael C Tucker

Constantin I Stefan

Meilin Liu

Chun Lu

Marcus Y Peng

Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

Joined concentric tubes

Porous substrates and associated structures for solid-state electrochemical devices, such as solid-oxide fuel cells (SOFCs), are low-cost, mechanically strong and highly electronically conductive. Some preferred structures have a thin layer of an electrocatalytically active material (e.g., Ni&#x2014;YSZ) coating a porous high-strength alloy support (e.g., SS-430) to form a porous SOFC fuel electrode. Electrode/electrolyte structures can be formed by co-firing or constrained sintering processes.

Structures and fabrication techniques for solid state electrochemical devices

A composite solid electrolyte include a monolithic solid electrolyte base component that is a continuous matrix of an inorganic active metal ion conductor and a filler component used to eliminate through porosity in the solid electrolyte. In this way a solid electrolyte produced by any process that yields residual through porosity can be modified by the incorporation of a filler to form a substantially impervious composite solid electrolyte and eliminate through porosity in the base component. Methods of making the composites is also disclosed. The composites are generally useful in electrochemical cell structures such as battery cells and in particular protected active metal anodes, particularly lithium anodes, that are protected with a protective membrane architecture incorporating the composite solid electrolyte. The protective architecture prevents the active metal of the anode from deleterious reaction with the environment on the other (cathode) side of the architecture, which may include aqueous, air and organic liquid electrolytes and/or electrochemically active materials.

Composite solid electrolyte for protection of active metal anodes

A novel electrochemical cell which may be a solid oxide fuel cell (SOFC) is disclosed where the cathodes () may be exposed to the air and open to the ambient atmosphere without further housing. Current collector () extends through a first cathode on one side of a unit and over the unit through the cathode on the other side of the unit and is in electrical contact via lead () with housing unit (and). Electrical insulator () prevents electrical contact between two units. Fuel inlet manifold () allows fuel to communicate with internal space () between the anodes (and). Electrically insulating members (and) prevent the current collector from being in electrical contact with the anode.

Compact fuel cell

A process and apparatus for the electrolytic separation of fluorine from a mixture of gases is disclosed. Also described is the process and apparatus for the generation of fluorine from fluorine/fluoride containing solids, liquids or gases.

Fluorine separation and generation device

Provided is a composite electrochemical device fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems including oxygen generation system.

Solid state electrochemical composite

Porous substrates and associated structures for solid-state electrochemical devices, such as solid-oxide fuel cells (SOFCs), are low-cost, mechanically strong and highly electronically conductive. Some preferred structures have a thin layer of an electrocatalytically active material (e.g., Ni&#x2014;YSZ) coating a porous high-strength alloy support (e.g., SS-) to form a porous SOFC fuel electrode. Electrode/electrolyte structures can be formed by co-firing or constrained sintering processes.

Low-cost, mechanically strong, highly electronically conductive porous substrates and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures provide solid state electrochemical device substrates of novel composition and techniques for forming thin electrode/membrane/electrolyte coatings on the novel or more conventional substrates. In particular, in one aspect the invention provides techniques for co-firing of device substrate (often an electrode) with an electrolyte or membrane layer to form densified electrolyte/membrane films 5 to 20 microns thick. In another aspect, densified electrolyte/membrane films 5 to 20 microns thick may be formed on a pre-sintered substrate by a constrained sintering process. In some cases, the substrate may be a porous metal, alloy, or non-nickel cermet incorporating one or more of the transition metals Cr, Fe and Cu, or alloys thereof.

Provided are low-cost, mechanically strong, highly electronically conductive porous substrates and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical device substrates of novel composition and techniques for forming thin electrode/membrane/electrolyte coatings on the novel or more conventional substrates. In particular, in one embodiment the invention provides techniques for co-firing of device substrate (often an electrode) with an electrolyte or membrane layer to form densified electrolyte/membrane films 5 to 20 microns thick. In another embodiment, densified electrolyte/membrane films 5 to 20 microns thick may be formed on a pre-sintered substrate by a constrained sintering process. In some cases, the substrate may be a porous metal, alloy, or non-nickel cermet incorporating one or more of the transition metals Cr, Fe, Cu and Ag, or alloys thereof.

Provided are low-cost, mechanically strong, highly electronically conductive porous substrates and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical device substrates of novel composition and techniques for forming thin electrode/membrane/electrolyte coatings on the novel or more conventional substrates. In particular, in one embodiment the invention provides techniques for firing of device substrate to form densified electrolyte/membrane films 5 to 20 microns thick. In another embodiment, densified electrolyte/membrane films 5 to 20 microns thick may be formed on a pre-sintered substrate by a constrained sintering process. In some cases, the substrate may be a porous metal, alloy, or non-nickel cermet incorporating one or more of the transition metals Cr, Fe, Cu and Ag, or alloys thereof.

Process for making dense thin films

A disclosed method provides techniques for forming low-cost, mechanically strong, highly electronically conductive porous structures for solid-state electrochemical devices. In particular, a method of forming a ceramic film on a substrate using electrophoretic deposition (EPD) is described. The method employs a colloidal dispersion of particles during the EPD process where a distribution of particle sizes is selected to eliminate drying cracks in the ceramic film prior to firing of the ceramic film-coated substrate. The method may be used to provide a high-density green film which can be sintered on to a non-shrinking substrate. For instance, a thin film of YSZ with a high green density may be sintered on to a non-shrinking LSM substrate. In particular embodiments, the distribution of particle sizes used in the EPD process may be selected to reduce a firing temperature and a firing time during sintering of the film coated substrate.

Method for making thin-film ceramic membrane on non-shrinking continuous or porous substrates by electrophoretic deposition

An electrode/electrolyte structure is prepared by a plurality of methods. An unsintered (possibly bisque fired) moderately catalytic electronically-conductive or homogeneous mixed ionic electronic conductive electrode material is deposited on a layer composed of a sintered or unsintered ionically-conductive electrolyte material prior to being sintered. A layer of particulate electrode material is deposited on an unsintered ('green') layer of electrolyte material and the electrode and electrolyte layers are sintered simultaneously, sometimes referred to as 'co-firing,' under conditions suitable to fully densify the electrolyte while the electrode retains porosity. Or, the layer of particulate electrode material is deposited on a previously sintered layer of electrolyte, and then sintered. Subsequently, a catalytic material is added to the electrode structure by infiltration of an electrolcatalyst precursor (e.g., a metal salt such as a transition metal nitrate). This may be followed by low temperature firing to convert the precursor to catalyst. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in an ionic (electrochemical) device such as fuel cells and electrolytic gas separation systems.

Method of making a layered composite electrode/electrolyte

Provided are low-cost, mechanically strong, highly electronically conductive current collects and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical devices having as current interconnects a ferritic steel felt or screen coated with a protective oxide film.

Metal current collect protected by oxide film

A method employing a bonding layer is used to form active metal electrodes having barrier layers. Active metals such as lithium are highly reactive in ambient conditions. The method involves fabricating a lithium electrode or other active metal electrode without depositing the barrier layer on a layer of metal. Rather a smooth barrier layer is formed on a smooth substrate such as a web carrier or polymeric electrolyte. A bonding or alloying layer is formed on top of the barrier layer. Lithium or other active material is then attached to the bonding layer to form the active metal electrode. A current collector may also be attached to the lithium or active metal during the process.

Encapsulated lithium alloy electrodes having barrier layers

Provided is an electrode fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. Onto this electrode in the green state, a green ionic (e.g., electrolyte) film is deposited and the assembly is co-fired at a temperature suitable to fully densify the film while the substrate retains porosity. Subsequently, a catalytic material is added to the electrode structure by infiltration of a metal salt and subsequent low temperature firing. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems.

Growing community of inventors

Lafayette, CA, United States of America

Lutgard C DeJonghe