Florian Rittweger

TL;DR: In this paper, the volume and longitudinal and transverse moduli of a carbon fiber at three states of lithiation are determined and compared. And the transverse and longitudinal modulus of the lithiated fibre is found to be more than double that of pristine and delithiated fibres.

TL;DR: In this article, optical fiber measurements for cell state determination via simultaneous observation of both electrodes of a lithium-ion battery were performed using commercial electrodes set up in a pouch configuration, and results showed that the cell state of charge directly influences both transmission signals.

TL;DR: In this article, optical in situ investigations of lithium-ion dynamics in lithium iron phosphate based positive electrodes are presented, where the change in reflectivity of these cathodes during charge and discharge is used to estimate apparent diffusion coefficients for the lithiation and delithiation process of the entire electrode.

TL;DR: The origin of an optical effect in lithium iron phosphate (LFP) battery cathodes, which depends on the electrical charge transferred into the battery, is discussed, which allows for novel battery research methods and for a possible commercial application as a sensor for state-of-charge estimation.

TL;DR: In this paper, the authors discuss some major obstacles and solutions towards an industrialization of optical fiber sensors for cell state monitoring of lithium-ion batteries and present measurement results based on transmitted light intensities through the optical fiber as indicator for the state of charge.