Forschungszentrum Energiespeichertechnologien

Background:Lead-contaminated soils in former mining areas can pose an environmental hazard for decades. In the former mining district of Goslar, Germany, where mining ceased in 1988, soil lead exposure remains a public health concern, with median soil lead concentrations reaching up to 1,500 mg/kg in residential areas. Children are particularly vulnerable to lead exposure due to physiological and behavioral factors. This study aimed to assess blood lead levels (BLLs) in children and identify key exposure pathways.Methods:In a cross-sectional study conducted in 2023/24, BLLs were measured in 310 5–7-year-old children. Guardians provided information on potential exposure pathways, including handwashing behavior, hand-to-mouth contact, consumption of homegrown/foraged food, outdoor activity, and secondhand smoke. Children’s locations of residence and recreation were assessed, and soil contamination data were available. Factors were analyzed using bivariate comparisons and adjusted linear regression model.Results:The BLL geometric mean was 22.7 μg/L. Of the children, 51% exceeded the German reference values (19/22 μg/L girls/boys), and 24% exceeded the US reference value (35 μg/L). Thirteen percent had BLLs above 50 μg/L, the World Health Organization benchmark for preventive action. Soil contamination emerged as the main exposure pathway. Children living in very highly contaminated areas had BLLs 29% higher (95% CI: 7%, 56%) than those in the least contaminated areas.Conclusions:These results emphasize the importance of continuing and strengthening preventive measures to reduce lead exposure and intake. Given similar historical contamination in other regions, more extensive environmental assessments and targeted interventions are required to protect children’s health in former mining areas worldwide.

Technological maturity serves as a critical indicator for evaluating the current state of technology development and forecasting future trends. It has been widely applied in high‐tech fields, defense, and strategic emerging industries. This paper develops a multidimensional technology maturity assessment framework based on a comprehensive evaluation of existing maturity assessment methods and relevant application studies. The proposed model correlates computed values with the nine levels of technology readiness levels (TRLs) and the four stages of Theory of Inventive Problem Solving (TRIZ), providing a quantitative supplement to these classifications. Utilizing this evaluation model, the maturity levels of five underground compressed air and hydrogen storage power generation (UCHPG) technologies were assessed. The results, as of 2023, reveal that compressed air energy storage (CAES) has attained the highest TRL of 9. Conversely, hydrogen energy storage and fuel cell (HES‐FC) systems achieved a TRL of 7, hydrogen‐heated CAES (HH‐CAES) and hydrogen energy storage and gas turbine (HES‐GT) systems both reached a TRL of 6, while advanced adiabatic CAES (AA‐CAES) obtained a lower TRL of 5. To validate the proposed assessment model, a comparative analysis was conducted with recent literature on the TRL classifications of these five technologies. The findings indicate that the multicriteria technology maturity evaluation model proposed in this paper is reliable, addressing the limitations of single‐criterion assessment methods and providing a more comprehensive evaluation of technology maturity.

Oxygen tracer self‐diffusion in LiNbO3, LiTaO3, and LiNb0.15Ta0.85O3 single crystals between 880 and 1050 °C is investigated. 18O2 isotope‐exchanged samples are analyzed by secondary ion mass spectrometry. The diffusivities of each of the three different materials can be described by the Arrhenius law with an activation enthalpy of diffusion of about 3.2–3.5 eV. The diffusivities are highest for LiNbO3 and are lower by about one order of magnitude for LiNb0.15Ta0.85O3 and LiTaO3. The change of the pre‐exponential factor is identified as the reason for the difference in diffusivities. The experimental results are compared to defect formation energy calculations as given in literature and to energy barrier calculations for the diffusion of a single O vacancy as determined by nudged elastic band calculations based on density‐functional theory. An oxygen vacancy mechanism is suggested to govern diffusion. The difference in diffusivities is tentatively attributed to a different number of freely migrating vacancies, probably due to defect complex formation.

Abstract Large‐scale underground hydrogen storage (UHS) provides a promising method for increasing the role of hydrogen in the process of carbon neutrality and energy transition. Of all the existing storage deposits, salt caverns are recognized as ideal sites for pure hydrogen storage. Evaluation and optimization of site selection for hydrogen storage facilities in salt caverns have become significant issues. In this article, the software CiteSpace is used to analyze and filter hot topics in published research. Based on a detailed classification and analysis, a “four‐factor” model for the site selection of salt cavern hydrogen storage is proposed, encompassing the dynamic demands of hydrogen energy, geological, hydrological, and ground factors of salt mines. Subsequently, 20 basic indicators for comprehensive suitability grading of the target site were screened using the analytic hierarchy process and expert survey methods were adopted, which provided a preliminary site selection system for salt cavern hydrogen storage. Ultimately, the developed system was applied for the evaluation of salt cavern hydrogen storage sites in the salt mines of Pingdingshan City, Henan Province, thereby confirming its rationality and effectiveness. This research provides a feasible method and theoretical basis for the site selection of UHS in salt caverns in China.

The internal short circuit (ISC) in lithium-ion batteries is a serious problem since it is probably the most common cause of a thermal runaway (TR) that still presents many open questions, even though it has been intensively investigated. Therefore, this article focusses on the generation and characterisation of the local single-layer ISC, which is typically caused by cell-internal impurity particles that cannot be completely eliminated in the cell production. A new, very promising method of precise and slow (1 μm s−1) needle penetration made it possible to generate the most safety-critical reliable short-circuit type—the contact between the Al-Collector and the graphite active material of the anode—as demonstrated on a 10 Ah Graphite/NMC pouch cell. The special efforts in achieving high reproducibility as well as the detailed analysis of the initiated internal short-circuit conditions led to more reliable and meaningful results. A comprehensive approach to characterisation has been made by detailed measurement of the dynamic short-circuit evolution and a subsequent post-characterisation, which included the application of different electrochemical measurement techniques as well as a post-abuse analysis. It was shown that the cells demonstrated a very individual and difficult-to-predict behaviour, which is a major challenge for early failure detection and risk assessment of cells with an existing or former ISC. On the one hand, it is found that despite high local temperatures of over 1260 ∘C and significant damage to the cell-internal structure, the cell did not develop a TR even with further cycling. On the other hand, it was observed that the TR occurs spontaneously without any previous abnormalities. Based on the overall test results, it was shown that at the high state of charge (SOC = 100%), even small, dynamically developing voltage drops (<10 mV) must be classified as safety-critical for the cell. For reliable and early failure detection, the first voltage drops of the ISC must already be detected.

Zusammenfassung Im Rahmen der Fördermaßnahme „Innovative Konzepte zum Ausbau der China-Kompetenz an deutschen Hochschulen“ des Bundesministeriums für Bildung und Forschung, wurde 2018 ein China-Kompetenzzentrum an der TU Clausthal errichtet. Mit dem Ziel die deutsch-chinesische Zusammenarbeit zu stärken, sollten u. a. der Auf- und Ausbau von China-Kompetenz aller Hochschulangehörigen als auch die Kooperationen mit bestehenden aber auch neuen chinesischen Partnerhochschulen intensiviert werden. Die dazu im Rahmen der Eröffnung des China-Kompetenzzentrums initiierte, seither jährlich stattfindende China Woche hat sich dabei in kürzester Zeit zu einer überregional und international bekannten Veranstaltung entwickelt. Sie versteht sich als interkulturelle Kommunikationsplattform für einen konstruktiven Dialog, an dem sich prominente Akteur*innen der Wissenschaft, Wirtschaft und Politik aus Deutschland und China beteiligen. Der folgende Beitrag beschreibt den genauen Entstehungshintergrund und analysiert die Entwicklung der Veranstaltung seit 2018, um schließlich den Beitrag zur interkulturellen Kommunikation zwischen Deutschland und China darzustellen.