GOALI: Experimentally validated multiscale modeling of Li/O2 cathodes

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

PI: Monroe, Charles Proposal Number: 1336387 Institution: University of Michigan Ann Arbor Title: GOALI: Experimentally validated multiscale modeling of Li/O2 cathodes This collaboration project between the University of Michigan (UM) and Robert Bosch Research and Technology Center (Bosch RTC) will focus on development of robust multiscale models of rechargeable Li/air cathodes. A viable Li/air battery would speed efforts to electrify transportation. Conservative projections suggest that Li/air stacks could achieve energy densities near 1 kWh/kg. This allows single-charge driving distances of 400 miles, matching combustion-driven cars. The PIs propose to show what phenomena most impact Li/air cell performance by informing predictive continuum electrochemical models with electronic structure calculations and experimental data. The hybrid multi-scale modeling/experimental approach will elucidate discharge/charge mechanisms, voltage response, and performance of rechargeable aprotic Li/air cells. The team combines expertise in continuum modeling, ab initio computation, and experimental electrochemical and structural characterization. The academic/industrial collaboration will support the Energy for Sustainability Program objective to improve the fundamental understanding of advanced energy-storage technologies for transportation, for two primary research objectives: (1) to develop a flexible, experimentally benchmarked multi-scale modeling framework. Simulations will incorporate both experimental measurements and ab initio predictions of material properties into a predictive continuum-scale Li/air cell model with a 3-phase cathode structure; and (2) to use the modeling framework to identify, quantify, and predict performance-limiting phenomena in rechargeable Li/air cells. The mechanistic insight gained will reveal strategies to overcome limitations and accelerate development of viable Li/air batteries for vehicles. Simultaneous theoretical and experimental efforts will parameterize and validate the multi-scale theoretical model, reliant on molecular-scale thermodynamic, kinetic, and transport properties, to simulate the macroscopic response of Li/air cells during discharge or charge. The approach will improve the field?s limited knowledge about elementary reaction mechanisms in Li/air-battery cathodes, and will correlate atomic-scale bulk and interfacial material properties with cell-level performance metrics such as accessible capacity, rate capability, and efficiency. Building on a current collaboration with Li/air researchers at Bosch RTC, scientific exchanges will be strengthened by student internship experiences at Bosch and visits of Bosch researchers to UM. The outreach activities will foster the natural connection between research and pedagogy. Here the chief aim is to establish a collaborative, diverse environment for electrochemical research to achieve four primary educational goals: (1) Integration of research problems into a course module in a graduate Electrochemical Engineering course, webcast simultaneously to reach students seeking technical degrees; (2) Exposure of undergraduates to energy-storage technology by offering undergraduate research opportunities and developing forums outside the classroom for idea exchange; (3) Outreach to support participation by under-represented minorities and women in science, technology, engineering, and mathematics; and (4) Dissemination of research products via peer-reviewed publications, conference presentations, and biweekly meetings with UM metal/air battery researchers.