GHz nanoscale electrical and dielectric measurements of the solid-electrolyte interface and applications in the battery manufacturing line

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Sustainable storage of electrical energy is one of this century’s main challenges, and battery production is one of the future key industries with an estimated market potential of 250 Billion Euros by 2025 as stated by the European Commission. We contribute to this by establishing an RF-nanotechnology toolbox for Li-ion batteries and beyond Lithium batteries. The specific focus is on the nanoscale structure of the 10-50 nm thick SEI (solid electrolyte interphase) layer, which is of pivotal importance for battery performance and safety, but which is difficult to characterize and optimize with currently available techniques. The toolbox contains new nanoscale high-frequency GHz methods that are ultra-fast and capable of testing and quantifying the relevant electrical processes at the SEI, several orders of magnitude better than currently available techniques. Nanoscale imaging of the SEI electrical conductivity at high GHz frequencies will be done for the first time, and impedance changes are measured during electrochemical processes, supported by advanced modelling and simulation techniques. Several methods are tested in pilot-lines, including advanced electrochemical impedance spectroscopy and a newly developed self-discharge method that shortens the electrical formation process in battery production from 2 weeks to 10 min. Finally, the new methods will be used for high-throughput incoming quality control in the battery module production at our automotive end users, where 30.000 cells will be tested per day. In summary, we develop a solid basis of GHz-nanotech instrumentation to improve cell production and testing, resulting in major advantages for manufacturers and customers, for instance reduced waste and energy consumption, and longer lasting batteries that are safer with 90% improved thermal runaway. Project results will be disseminated to a large stakeholder group, with technical workshops (e.g. e-car rally) and conferences in nanotech and battery production.