ISBN 9783843945042

978-3-8439-4504-2, Reihe Energietechnik

Georg Lenze
Simulation-supported investigation of manufacturing impacts on the performance of lithium-ion-battery cells

128 Seiten, Dissertation Technische Universität Braunschweig (2020), Softcover, A5

Zusammenfassung / Abstract

Lithium-ion-batteries are the technical bottleneck of electric vehicles. To improve their cost-benefit ratio, it is important to understand battery physics entirely and the impact of manufacturing parameters on it.

Within this work, impacts of electrode thickness, calendering stress load and carbon black content on the cell performance were analyzed for two different cathode materials, respectively.

In an experimental evaluation C-Rate test results of various cells were compared; also energy and power densities were analyzed.

Then for simulative investigation a physico-chemical P2D model was used. An individual parameterization strategy was developed and optimized by implementation of a least square algorithm in order to improve time effectiveness. The correlations between calendering stress load and cell performance were analyzed in depth to show the dominant limiting impact on effective electronic conductivity of NMC cathodes.

Afterwards the model was numerically reparameterized to detect dominant performance limiting processes for several cells with individual production parameter configurations.

It was shown that the method presented in this work enables to identify whether losses are mainly caused by electrochemical kinetics, by electrical or ionic transport and where the performance bottleneck is located (within the anode, separator or cathode region).