SKM 2023 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 42: Battery Materials (joint session KFM/CPP)

CPP 42.2: Vortrag

Donnerstag, 30. März 2023, 09:20–09:40, POT 51

Structural response in NCA-type battery cathodes — •Tobias Hölderle^1,2, Peter Müller-Buschbaum^1,2, and Anatoliy Senyshyn² — ¹TUM School of Natural Sciences, Chair for Functional Materials, Garching, Germany — ²MLZ, TUM, Garching, Germany

Battery-powered electric drivetrains in electric vehicles (EVs) are heavily limited and constrained to the performance of the energy storage device, i.e. battery. Batteries with higher power/energy densities, capacities, and cycling life are needed to increase EVs’ performance and reduce greenhouse gas emissions. Mixed high nickel content Li_xNi_0.8Co_0.15Al_0.05O₂ (NCA) cathode material is one of a few today that simultaneously possess high energy and power densities at lower costs. However, NCA materials suffer from poor thermal stability and limited power density. They display capacity fading/efficiency loss due to antisite defects (cation mixing) in their structure, actively discussed in literature. In order to address the issue of cation mixing, a systematic ex-situ neutron powder diffraction study was done for a series of electrochemically delithiated NCA cathodes. The collected set of structural data was modeled using full-profile Rietveld method and results were discussed in line with observed electrochemical behavior. It is observed that lithium occupancies showed a decreasing character upon charging, independent from transition metal occupancies and indicating an absence of antisite defects (cation mixing) in the commercial NCA material during cell operation.