[The] PTB is Germany’s national metrology institute, providing internationally recognised calibration and measurement services. With its expertise, PTB supports industry and society with accuracy and quality assurance in battery cell production by means of traceable, quantitative methods for characterising key performance and safety parameters across the battery lifecycle.
We use Electrochemical Impedance Spectroscopy (EIS) for non-destructive evaluation of battery state-of- charge and state-of-health. This fast, and cost-effective method provides insights into internal battery processes in a non-inversive way. We will show that, under well-defined conditions, EIS delivers reproducible results with uncertainties as low as 1–3 %, making it a promising tool for quality assurance in production, workshops, and even in-vehicle diagnostics.
Additionally, we will show how magnetic field sensors—such as fluxgates and optically pumped magnetometers—enable spatially resolved imaging of current density during charging, discharging, and relaxation. This technique may allow to detect irregularities occurring during cell production. These measurements support the optimisation of cell design and performance.
We outline thermal investigations using calorimetry methods to determine heat generation, flux, capacity, and thermal behaviour of battery cells. These results contribute to safety assessments and thermal management strategies.
We present quantitative and traceable operando X-ray spectrometry (XRS) as a powerful tool to gain chemical insights into battery materials during operation. Using techniques such as X-ray fluorescence (XRF) and near-edge X-ray absorption spectroscopy (NEXAFS), we investigate changes in material composition and obtain time resolved information on relevant species while cycling the battery cells. We will show how this approach helps to understand ageing mechanisms and supports the development of more durable battery materials.
We also outline PTB’s contributions to recycling strategies and the development of a digital battery passport. This digital product passport, developed within the QI-Digital project, enables standardised, traceable data exchange across the battery value chain. It supports international harmonisation of digital quality infrastructure and facilitates informed decisions for sustainable battery technologies.