RII Track-4: Pore-Scale Transport Phenomena in Li-O2 Battery Electrodes Characterized by Nano-Tomography

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

Nontechnical Description Rechargeable batteries with high specific energy and power are the key for high-performance and long-range electric vehicles as well as many portable power applications. The lithium-oxygen (Li-O2) battery has great potential as the next generation energy storage technology. However, the current achievable specific energy (i.e., energy per unit mass) for Li-O2 batteries is a factor of ten lower than its theoretical limit and their current power performance are still far below the acceleration performance required for electric vehicles. Both of these limitations are partially due to the sluggish mass transfer of oxygen in the electrode. Increasing the specific energy requires fundamental knowledge of pore-scale material transport in battery electrodes. To fill this knowledge gap, the PI will work with collaborators at Carnegie Mellon University (CMU) to measure and reconstruct the pore-scale structure of Li-O2 battery electrodes and propose criteria for fundamentally improving the electrochemical performance of Li-O2 batteries. Research findings from this Fellowship will also be integrated into curriculum development efforts to transmit the new theory and knowledge to young researchers, train undergraduate and graduate students, and nurture a skilled and educated professional workforce to grow local industry and economy. Technical Description The collaboration with Prof. Shawn Litster and access to the unique X-ray Computed Tomography Facility (XCFT) at CMU, made possible by this Fellowship, is the key to reconstructing high-resolution (~50 nm) pore-scale structure and for subsequent studies of Li-O2 batteries. The reconstructed three-dimensional nano-tomography of customized battery electrodes will 1) be integrated with statistical models to transfer pore-scale morphology to electrode-level properties; 2) be coupled with fluid dynamics models to predict its electrochemical performance; and 3) facilitate the understanding of pore structure evolution caused by the solid Li2O2 precipitation/depletion during discharge/charge. The new knowledge and theory, as well as the new techniques, developed in this project will enable research and development of advanced electrode materials to significantly improve the specific energy and power of Li-O2 batteries. The profound scientific significance will last beyond this Fellowship and promote electrochemical technologies with high energy and power density such as fuel cells, Li-ion batteries, metal-air batteries, super capacitors, and redox flow batteries. The success of this project will initiate a longstanding collaboration between the PI and Prof. Litster to pursue new knowledge and foster more collaborative research between the University of Kansas and CMU. It also provides an excellent opportunity for one graduate student to receive systematic training on conducting scientific research, initiating collaborations, and disseminating research findings each summer. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.