Description: Industry and other government agencies are advancing battery, fuel cell, and electrolyzer technology to reduce costs and increase specific power. However, NASA's unique missions with extreme conditions and difficulty in replacing batteries require even greater specific power improvements in conjunction with long life and performance at extremely high or low temperatures. Predictive models, incorporating the thermodynamics and electrochemistry that dictates device performance and degradation, are needed to accelerate development and insertion of these systems. To provide this capability, CFDRC and our collaborator Dr. Partha Mukherjee, TAMU, will develop and validate detailed models that link chemical composition and elementary reaction steps with the properties and reactions of electrochemical system constituents. The proposed electrochemical models will be based on fundamental chemical and electrochemical properties of the materials, as opposed to empirical fits of observed properties for a specific battery electrode material and electrolyte mixture or fuel cell catalyst, support, and electrolyte combination. A property database and software library will be used and extended, allowing application of the developed models in performance simulators of NASA preference. The ability of the developed models to incorporate detailed thermodynamics and electrochemical kinetics of degradation processes will be demonstrated during Phase I, with extension to additional materials and validation during Phase II. The resulting models will significantly reduce the need for iterative, trial-and-error tests of new materials to accelerate development and increase confidence in projected device lifetimes.

Benefits: The proposed models will allow the results of first-principles modeling and systematic characterization of electrochemical system component materials to be applied in predicting the performance of electrochemical energy storage and energy generation devices. This technology will accelerate development by enabling prediction of the rates of both desirable and undesirable processes for a given material system, without extensive calibration for each new device. The models will support transition of new materials from laboratory to program-specific hardware by enabling confident estimation of performance under baseline and extreme conditions. Because these models are based on fundamental material properties and elementary reaction steps, they will enable NASA to leverage the plethora of research into next-generation materials for terrestrial applications by improving the understanding of elementary reactions governing material interactions, i.e. performance and life limiting processes.

The developers and producers of rechargeable batteries for satellite applications will benefit directly from these models, as these applications also have very stringent demands on specific energy and battery cycle life. The commercial and government sector entities developing batteries and fuel cells for the automotive industry will also be able to directly leverage this technology for faster development and increased confidence in life projections for consumer warranties. Similarly, the developers of grid-scale energy storage devices that are coupled with intermittent power generation technologies such as wind and solar will directly benefit from this technology.