Remarkable advances have been made over the last decade in energy conversion and storage devices such as fuel cells, thermoelectric generators, batteries, and super-capacitors. These are expected to play an ever-growing role in meeting our energy needs. In large part, progress is due to fabrication of structures at the nano-scale: improved electrocatalysts for oxygen reduction, low-dimensional thermoelectric materials, and highly conductive olivine materials used in advanced rechargeable batteries for instance. In order for these devices to impact the energy challenge, they must be affordable-a critical aspect of which is their long-term stability in service-a fundamental issue for nanostructures. Georgia Institute of Technology will investigate the structure and function of materials and use physics-based modeling to elucidate the ageing mechanisms of nanoscale catalysts. Fundamental questions about the surface energy of nanometer sized particles will be addressed and the results integrated into physics-based models of catalyst ageing. From a detailed mechanistic understanding of failure mechanisms, the broader objectives of the work are to guide the development of new materials and to identify strategies to mitigate these failure modes in full systems.
Broader Impact The number of vehicles in the world is approaching 1 billion, and these contribute about 20 percent of the anthropogenic emissions of CO2. What's more, nearly all of these vehicles are powered with petroleum. Fuel cells and advanced lithium batteries show great promise as a future power sources. Both require electrodes with features with nanometer dimensions to improve kinetics, but whose structures can also be unstable. As a result of this, cost and durability are barriers that must be eliminated before these technologies are found in wide use commercially. A systematic framework will be developed to rigorously account for durability of electrochemical systems that can be generalized to ageing of catalysts and to other nano-scale devices. The program will provide graduate training and promote extensive interaction with industry. In addition to disseminating the results of this proposed research through publications and presentations, educational and outreach activities are integrated into the project. Outreach will be done through the LEAD program for ENGINEERSÂ®, summer programs with Morehouse College and local high schools with a high percentage of under-representative and low income students.