Engineering topics

Meinhardt, Kerry D

Publications and source records attributed to Meinhardt, Kerry D.

6 records

DOE OSTI2014

Cassette less SOFC stack and method of assembly

A cassette less SOFC assembly and a method for creating such an assembly. The SOFC stack is characterized by an electrically isolated stack current path which allows welded interconnection between frame portions of the stack. In one embodiment electrically isolating a current path comprises the step of sealing a interconnect plate to a interconnect plate frame with an insulating seal. This enables the current path portion to be isolated from the structural frame an enables the cell frame to be welded together.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2014

Methods and apparatuses for making cathodes for high-temperature, rechargeable batteries

The approaches for fabricating cathodes can be adapted to improve control over cathode composition and to better accommodate batteries of any shape and their assembly. For example, a first solid having an alkali metal halide, a second solid having a transition metal, and a third solid having an alkali metal aluminum halide are combined into a mixture. The mixture can be heated in a vacuum to a temperature that is greater than or equal to the melting point of the third solid. When the third solid is substantially molten liquid, the mixture is compressed into a desired cathode shape and then cooled to solidify the mixture in the desired cathode shape.

25 ENERGY STORAGE↗

DOE OSTI2012

Cassettes for solid-oxide fuel cell stacks and methods of making the same

Solid-oxide fuel cell (SOFC) stack assembly designs are consistently investigated to develop an assembly that provides optimal performance, and durability, within desired cost parameters. A new design includes a repeat unit having a SOFC cassette and being characterized by a three-component construct. The three components include an oxidation-resistant, metal window frame hermetically joined to an electrolyte layer of a multi-layer, anode-supported ceramic cell and a pre-cassette including a separator plate having a plurality of vias that provide electrical contact between an anode-side collector within the pre-cassette and a cathode-side current collector of an adjacent cell. The third component is a cathode-side seal, which includes a standoff that supports a cathode channel spacing between each of the cassettes in a stack. Cassettes are formed by joining the pre-cassette and the window frame.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2012

Optimized cell configurations for stable LSCF-based solid oxide fuel cells

Lanthanum strontium cobalt iron oxides (La(1-x)SrxCoyFe1-yO3-f; (LSCF) have excellent power density (>500 mW/cm2 at 750.degree. C.). When covered with a metallization layer, LSCF cathodes have demonstrated increased durability and stability. Other modifications, such as the thickening of the cathode, the preparation of the device by utilizing a firing temperature in a designated range, and the use of a pore former paste having designated characteristics and combinations of these features provide a device with enhanced capabilities.

25 ENERGY STORAGE↗

DOE OSTI2012

Demonstration of a Highly Efficient Solid Oxide Fuel Cell Power System Using Adiabatic Steam Reforming and Anode Gas Recirculation

Solid oxide fuel cells (SOFC) are currently being developed for a wide variety of applications because of their high efficiency at multiple power levels. Applications for SOFCs encompass a large range of power levels including 1-2 kW residential combined heat and power applications, 100-250 kW sized systems for distributed generation and grid extension, and MW-scale power plants utilizing coal. This paper reports on the development of a highly efficient, small-scale SOFC power system operating on methane. The system uses adiabatic steam reforming of methane and anode gas recirculation to achieve high net electrical efficiency. The anode exit gas is recirculated and all of the heat and water required for the endothermic reforming reaction are provided by the anode gas emerging from the SOFC stack. Although the single-pass fuel utilization is only about 55%, because of the anode gas recirculation the overall fuel utilization is up to 93%. The demonstrated system achieved gross power output of 1650 to 2150 watts with a maximum net LHV efficiency of 56.7% at 1720 watts. Overall system efficiency could be further improved to over 60% with use of properly sized blowers.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2012

Glass composition and process for sealing void spaces in electrochemical devices

A glass foaming material and method are disclosed for filling void spaces in electrochemical devices. The glass material includes a reagent that foams at a temperature above the softening point of the glass. Expansion of the glass fills void spaces including by-pass and tolerance channels of electrochemical devices. In addition, cassette to cassette seals can also be formed while channels and other void spaces are filled, reducing the number of processing steps needed.

36 MATERIALS SCIENCE↗