Fraunhofer-Publica

The Fraunhofer-Publica has been successfully documenting the research results of the Fraunhofer-Gesellschaft for over 30 years. The platform enables the collaborative linking of research-relevant objects and disseminates within the international scientific community.

The Fraunhofer-Publica thus fulfils its responsibility to promote the transfer of knowledge and know-how to industry and society.

Research outputs

As an application-oriented research organisation, Fraunhofer aims to conduct highly innovative and solution-oriented research - for the benefit of society and to strengthen the German and European economy.

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Projects

Fraunhofer is tackling the current challenges facing industry head on. By pooling their expertise and involving industrial partners at an early stage, the Fraunhofer Institutes involved in the projects aim to turn original scientific ideas into marketable products as quickly as possible.

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Researchers

Scientific achievement and practical relevance are not opposites - at Fraunhofer they are mutually dependent. Thanks to the close organisational links between Fraunhofer Institutes and universities, science at Fraunhofer is conducted at an internationally first-class level.

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Institutes

The Fraunhofer-Gesellschaft is the leading organisation for applied research in Europe. Institutes and research facilities work under its umbrella at various locations throughout Germany.

Recent Additions

Investigation of the influence of cell compression after winding on electrolyte wettability based on experiments and lattice Boltzmann simulation

( 2024)
Wanner, Johannes
;
Birke, Kai Peter

The wetting of the active materials in a lithium-ion battery cell after electrolyte filling is a time-critical process in the manufacturing of lithium-ion batteries. The exact influencing factors on wetting are the subject of experimental investigations and numerical simulations. The dominant wetting at the material transitions, depending on the material's compression caused by the cell winding, has not yet been examined. Therefore, this publication investigates the effects of material compression during the winding process on wettability through experiments and lattice Boltzmann simulations. The results show and quantify accelerated wetting caused in the material transitions compared to single electrode wetting, attributed to larger pores and higher permeability. Increasing compression in inner windings of cylindrical cells shows smaller pores sizes and reduced permeability, leading to a decelerated wetting behavior. Considering permeability and evaporation is essential for the mathematical replication of the wetting phenomena. With these findings, the total wetting time of a winding in a cylindrical 21 700 cell can be estimated between 816 s to 1198 s.
Comorbidity Analysis of Data from Psychiatric Disorder Patients with Polygenic Risk Scores and Potential Causal Effect of Single Nucleotide Polymorphisms

( 2023-09-20)
Zhang, Bide
;
Hofmann-Apitius, Martin
;
Tom Kodamullil, Alpha
The Power of Digitalization in Battery Cell Manufacturing

( 2024-02)
Wunderlich, Philipp
;
Ehteshami-Flammer, Niloofar
;
Krauß, Jonathan
;
Fitzner, Antje
;
Mohring, Leon
;
Dahmen, Christian

Digitalization plays a crucial role in mastering the challenges in battery cell production at scale. This Whitepaper provides an overview of digital enabling technologies and use cases, presents the outcomes of an industry expert survey, and illustrates the results of battery production cost modeling for a chosen set of seven high-impact use cases. Battery and digitalization experts were invited to participate in an online survey aimed at gathering insights on how digital manufacturing solutions can enhance the primary cost drivers of battery cell production. The input is integrated into a Gigafactory model, which enables the quantification of cost and sustainability improvements when a cell manufacturer employs one of the use cases. The study results reveal that, in battery cell manufacturing, electrode production stands out as the primary beneficiary of digitalization, followed by cell finishing. The assembly process ranks third in terms of its potential for improvement through digitalization. The main production cost driver, as seen by the industry experts that participated in the survey, is above all the material scrap rate. The findings of the study quantify and affirm the many-faceted advantages of digitalization, including enhanced product yield, reduced machine downtimes, and increased energy efficiency. Specific use cases of digitalization, covering different lifecycles of a plant, are analyzed in detail regarding their impact on the metrics in the field of operations, sustainably and costs. The data show that the implementation of predictive quality and traceability solutions stand out as the most effective levers to reduce battery material scrap rates by up to 10.3%, compared to a baseline scenario. Predictive maintenance allows to increase machine uptime by 7.2%, while energy management solutions can cut energy consumptions and related emissions by 9.3%. Simulation use cases with a virtual-first approach, such as digital production planning, virtual commissioning, and material flow modeling, contribute to de-bottleneck cell manufacturing operations and result in moderate production cost savings. In a lithium-ion battery cell Gigafactory with annual production capacity of 40 GWh/a, the best investigated use cases offer roughly 0.8% reduction in cell production costs which translate into a potential annual saving of $30M. When considering the initial investment and operational costs for the digital solutions, all use cases result in a net positive cash flow after a few years in operation. Primarily software-based solutions demonstrate scalability and ease of implementation, whereas applications with greater hardware intensity demand closer scrutiny in terms of their payback period. This study emphasizes that digitalization provides competitive advantages to battery cell manufacturers, but the costs and benefits of digital manufacturing use cases must be carefully analyzed and evaluated in terms of their economic advantage. The methodology outlined in this work aids cell manufacturers in making well-founded decisions, serving as a compass that directs the battery industry toward sustainable and impactful digital transformation roadmaps.
Retrofitting of a Solar Cooling and Heating Plant by Employing Pcm Storage and Adjusting Control Strategy

( 2024)
Huang, Li
;
Piontek, Udo
;
Zou, Deqiu
;
Zhuang, Lulu
;
Zheng, Rongyue

A solar cooling and heating plant with a 1,000 L hot water storage tank has been operated since 2018. Two main problems were observed: (1) a fluctuating operation of the absorption chiller due to a high number of stat-up and shut-down procedures; (2) high electricity consumption caused by a low solar fraction SFn of 62.1% during the cooling period. In 2021, the solar plant was retrofitted by employing a shell and tube heat exchanger based on a PCM melting at 64 oC and by adjusting the control strategy. The system performance was evaluated and compared before and after retrofitting based on the operational data in 2021 and 2022. The total number of switch-on times of the chiller shrank by 33.5% and the operation time was increased by 65% in 2022 due to the stable hot water inlet temperature. Contributing to the high heat storage capacity of the PCM storage, more solar thermal energy was utilized and the average SFn reached 90.7% during the cooling period in 2022, leading to a 24.4% reduction in the total electricity consumption compared to 2021.

Most viewed

Laser pulse energy conversion on sequence-specifically bound metal nanoparticles and its application for DNA manipulation

( 2005)
Garwe, F.
;
Czaki, A.
;
Maubach, G.
;
Steinbrück, A.
;
Weise, A.
;
König, K.
International Solid-State Circuits Conference 1994
Measurement of Local Recombination Activity in High Diffusion Length Semiconductors

( 2023)
Heinz, Friedemann
;
Oezkent, Maximilian
;
Rittmann, Clara
;
Schindler, Florian
;
Schubert, Martin
;
Kwapil, Wolfram
;
Glunz, Stefan

We present a conceptual approach for the localisation and characterisation of local sites of recombination in high diffusion length semiconductors under photovoltaic field conditions. While established imaging techniques operate in this very regime of uniform "1 sun" illumination, inevitable lateral diffusion of charge carriers veils the origin and severity of localised recombination sites. To reduce this limitation due to lateral diffusion the natural choice is using focussed charge carrier excitation and detection in combination with scanning the specimen. The resulting photoluminescence intensity maps are of high spatial resolution and may be composed of a superposition of a multitude of recombination active defects influencing each other due to the high bulk diffusion length. We demonstrate the feasibility of a self-consistent calibration of the setup quantum efficiency in such experimental condition which delivers a charge carrier density map in absolute units. A solution is presented to disentangle the superposition of local sites of recombination to isolate the actual recombination activity of every site. We demonstrate the feasibility of the approach experimentally on the high diffusion length semiconductor silicon.
27th International Symposium on Ballistics 2013. Proceedings. Vol.1: Interior Ballistics, Exterior Ballistics, Launch Dynamics, Vulnerability & Survivability, Explosion Mechanics

(DEStech Publications, 2013)