Seminar Date: Tuesday, January 21, 2025
Time: 11:00 AM PT
Location: 67-3111 & Zoom
Talk Title: An Omics Approach to Electrolyte Discovery for Lithium Metal Batteries for Electric Aircraft
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Abstract:
Electric aircraft require batteries with high energy density for cargo and range, as well as high power for take-off and landing operations. Lithium metal batteries incorporating nickel-rich layered oxide cathodes meet requirements for energy density. However, over time, these batteries experience a rise in impedance, leading to power fade, compromising the aircraft’s ability to land when the battery is at a low state-of-charge. Here, we translate omics to study battery systems, enabling a molecular to systems level understanding of aircraft battery electrolytes. By employing precision analytical capabilities across chemical space, we delineate the structure, function, and evolution of interphases arising from interactions between electrolytes and electrodes driven out of equilibrium by the applied. potential. In screens of locally superconcentrated electrolytes (LSCEs), we found that top-performers exploit non-obvious combinations of multiple lithium salts, solvents, and diluents to generate cathode–electrolyte interphases (CEI) that suppress leakage current, cathode corrosion, and cathode fracturing when cycling Li–NMC811 cells at high power and high voltage. Yet, despite their differences in composition, these top-performers converged in their CEI chemistry, which was unexpectedly enriched with fluoroethers (up-regulation) and depleted with LiF (down-regulation) contrary to the conventional wisdom. Pouch cells (130 mAh) assembled with 50-μm thick Li foil, semi-solid NMC811 electrodes (9 mAh cm –2 ) and lean electrolyte (2.2 Ah g –1 ) showed excellent power retention over more than 100 cycles using a realistic mission that enables electric vertical take-off and landing. Our results highlight the importance of considering cell chemistry, architecture, and mission when designing electrolytes for emerging segments in electric mobility. Furthermore, the omics approach emerges as a vantage point for tying battery performance to chemical complexity in battery interphases.
