Open Access

Lithium-ion batteries power portable devices, electric vehicles, and stationary power grids, yet hidden aging reactions still shorten their service life and raise concerns about cost and safety. An analytical proxy is needed to report these reactions and accelerate product development, quality control, and recycling. Here, we demonstrate that subtle shifts in the natural 7Li/6Li ratio accurately record the two decisive stages of cell aging, solid-electrolyte interphase (SEI) formation and field-driven aging, which can be detected using multi-collector ICP-MS. Because Li is easily stripped from digested electrodes or electrolyte in a one-step cation-exchange column, high-purity solutions reach the spectrometer in minutes. A streamlined MC-ICP-MS run yields a δ7LiLSVEC precision of 0.4 ‰, enabling dozens of battery fractions to be analyzed per day. Applying the workflow to LiCoO2 coin cells as models, sampled from pristine to 700 cycles, reveals a clear isotopic narrative. During the first ≈45 cycles, 7Li leaves the LiCoO2 lattice, dissolves into the electrolyte, and is locked in the SEI on graphite, driving cathode δ7Li from +8 to –10 ‰ and raising the anode to +13 ‰ while capacity drops by 10 %. After the interphase matures, the electric field takes over: the lighter 6Li migrates faster to the anode, 7Li accumulates in the contracting Li1-xCoO2 lattice, and the bulk separation factor rises to α≈1.045 by 700 cycles. The δ7Li curve flattens roughly 70 cycles before capacity falls to 80%, providing an early warning of end-of-life. Isotopic gradients scale linearly with impedance growth, SEI thickness, and crack density confirmed by LA-ICP-MS mapping, FIB-SEM, XANES, and EXAFS. Although each data point requires one cell, lithium-isotope fractionation provides direct, element-specific, and structural fatigue insight unavailable from non-destructive tests. The straightforward chemistry and fast MC-ICP-MS routine make the approach practical for targeted aging studies, additive screening, and forensic autopsies, complementing high-throughput electrochemical methods and supporting the design of longer-lived batteries.

This study explores Microwave-Inductively Coupled Atmospheric-pressure Plasma Mass Spectrometry (MICAP-MS) as a cost-effective alternative to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) for analyzing lithium isotopic composition in lithium-ion batteries (LIBs). We investigate the performance of MICAP-MS in measuring Li isotope ratios in new and aged commercial lithium cobalt oxide (LCO) batteries. Our results show that MICAP-MS, operating under cold plasma conditions at 800 W with an 8 mm torch position, achieves results metrologically compatible with MC-ICP-MS, with a precision ranging from 0.6‰ to 3.4‰ for δ7Li values. MICAP-MS benefits from a dielectric resonator for uniform plasma, better ion velocity control, and higher energy efficiency. Optimal settings were identified with dwell times of 10 ms for 6Li and 1 ms for 7Li. The study of LIBs revealed that 6Li migrates towards the anode over multiple charge–discharge cycles, causing 7Li to accumulate in the cathode, a fractionation effect that becomes more pronounced with prolonged cycling. MICAP-MS provides a cost-effective, precise alternative to MC-ICP-MS, with lower operational costs and enhanced portability, advancing the study of isotopic fractionation and aging in lithium-ion batteries.

The DCC enables automatization in the metrological traceability of measurements and the dissemination and processing of data from calibration services. Many calibration and measurement procedures, however, rely on certified reference materials (CRMs) to obtain metrological traceability, especially in the broad field of chemical analysis. The metrological information of those reference materials is also provided in the form of certificates, and hence, their digitization bears the same automatization potential for quality assurance and traceability as the DCC itself. Although fairly similar, a reference material certificate contains some different information, and has a variable structure and proprietary requirements compared to a calibration certificate, as it is based on the dedicated ISO 33401 standard (formally known as ISO Guide 31) rather than the ISO/IEC 17025. Accordingly, the established DCC-schema does not fully fit the purpose of machine-readable reference material certificates. At the German Federal Institute for Materials Research and Testing (BAM), we started to adapt the DCC-schema in order to derive a dedicated schema for CRM certificates. For the seamless digital description of its certified values and their uncertainties, the newly developed schema also utilizes the Digital SI and thus provides a direct link to BIPM’s digital reference point for a global harmonization of metrological quantities. Furthermore, the schema will also be suitable for non-certified reference materials in order to form a common data structure for digital reference material documents (DRMD) in general. As a validated XML report, the DRMD is also compatible with established digital security and verification infrastructure, such as electronic seals and the novel digital accreditation symbol. In this presentation we will highlight some of the essential differences between reference material documents and calibration certificates, but also point out their similarities, which well justify the derivation of the DRMD-Schema from the DCC. In addition to the metrological traceability and quality assurance, further automatization use cases by means of DRMDs are presented, ranging from database maintenance to machine learning for automated analytics. This work was supported in part by national QI-Digital initiative funded by the German Federal Ministry for Economic Affairs and Climate Action.

Per- and polyfluoroalkyl substances (PFASs) are a large group of emerging organic pollutants that contaminate the environment, food, and consumer products. Textiles and other outdoor products are a major source of PFAS exposure due to their water-repellent impregnations. Determination of PFASs in textiles is increasingly important for enhancing their contribution to the circular economy. While maximum levels and restrictions exist for certain key compounds under the Stockholm Convention on Persistent Organic Pollutants and the REACH regulation, certified reference materials (CRMs) are not currently available. To address this issue, the first CRM for determining PFASs in outdoor textiles (BAM-B003) was developed. It fully complies with the requirements of ISO 17034 and ISO 33405. This work presents the entire process of CRM development process, including preparation, a homogeneity study, a stability study, and value assignment. Certification was based on an in-house study at BAM using liquid chromatography tandem mass spectrometry (LC–MS/MS) with stable isotope dilution analysis (SIDA). The certified mass fractions of 18 PFASs range widely from 0.46 to 69 µg/kg, with a prevalence of PFOA (69 µg/kg), PFOS (41 µg/kg) and PFHxA (35 µg/kg) exceeding legal limits. BAM-B003 is intended for analytical quality control and contributes to improving the chemical safety of textiles and strengthening the circular economy.

Im Rahmen der Initiative QI-Digital wird ein digitales Referenzmaterial-Zertifikat (DRMD) entwickelt. Es basiert auf dem digitalen Kalibrierzertifikat (DCC) und ist ebenso wie dieses ein Element des Quality-X-Ökosystems. Die Entwicklung fokussiert zunächst auf zwei Produkte: das DRMD-XML-Schema einerseits und einen DRMD-Generator andererseits, mit dem händisch und/oder mittels KI DRMD-Dateien generiert werden können. Als Repositorium - und vor allem auch als PR-Maßnahme - könnte die COMAR-Datenbank dienen.