Fraunhofer IWKS' advancements in Hydro-mechanical Treatment

The urgent need for sustainable resource management has never been more pressing, particularly in light of the increasing demand for lithium-ion batteries (LIBs) driven by electric mobility. As the market for electric vehicles continues to expand, the recycling of end-of-life (EOL) batteries becomes crucial for reclaiming valuable materials and reducing environmental impact. As partner within the FREE4LIB project, the Fraunhofer IWKS, a leader in applied research, is at the forefront of developing innovative recycling technologies, particularly through its focus on hydro-mechanical processes such as Electrohydraulic Fragmentation (EHF).

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Importance of the Hydro-mechanical process

EHF represents a revolutionary approach to recycling LIBs by utilizing shockwave technology to fragment battery materials in a controlled environment, typically underwater. This method addresses several challenges associated with traditional recycling techniques, including high energy consumption, hazardous emissions, and the need for complex chemical processes. The significance of EHF lies in its ability to selectively disintegrate battery components, enabling the recovery of critical raw materials such as lithium, nickel, cobalt, and manganese with minimal contamination.

In conventional recycling methods like pyrometallurgy and hydrometallurgy, valuable metals often become sources of pollution and require extensive energy input. EHF offers a more sustainable alternative by achieving material separation at a lower energy cost while also minimizing the generation of harmful byproducts. This process not only enhances the efficiency of raw material recovery but also supports the circular economy by enabling the reuse of materials in new battery production.

Following the EHF fragmentation, the mixed material fractions undergo a succession process involving skimming and sieving. The entire process of EHF treatment, along with skimming and sieving post-treatment, plays a critical role in enhancing the purity of the recovered materials for several reasons:

1. Minimization of Dust Formation: The related processes are conducted in a wet environment, which effectively reduces dust emissions and minimizes the release of harmful substances into the environment.
2. Material Separation: The primary goal of the hydro-mechanical treatment is to obtain the black mass from the fragmented     materials while separating residual components such as housing, anode foil, cathode foil, separator foil, and plastic materials. This is achieved through a two-step process: sieving to isolate the black mass and skimming to separate floating and non-floating fraction particles.
3. Quality Control: The overall system ensures that the treated materials are as free from black mass contamination as possible, facilitating a downstream sorting process that can operate with minimal contamination.

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Goals and Implementation Strategies

The primary goal of the FREE4LIB project in advancing EHF technology is to maximize the recovery of critical raw materials from end-of-life LIBs while minimizing environmental impact. This includes enhancing material recovery efficiency, promoting sustainable recycling practices, and contributing to the establishment of industry standards for battery recycling.

To achieve its goals, Fraunhofer IWKS employs a comprehensive strategy that includes pilot plant operations for systematic testing and optimization of the EHF process, as well as collaborative research with industry stakeholders to enhance the technology's applicability across various battery chemistries. Advanced characterization techniques, such as ICP-OES and SEM-EDX, are also utilized to ensure the quality and purity of recovered materials.

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Technological Enhancements and Results

Fraunhofer IWKS' EHF process has demonstrated promising quantitative results in material recovery. The analysis revealed that shorter processing times resulted in a higher purity of the recovered black mass. For example, samples removed after half the processing time showed very low aluminum impurities, while longer processing times resulted in significantly higher impurities. The enrichment of valuable elements like cobalt, manganese, and nickel was also observed in samples subjected to extended processing, indicating effective recovery of these critical materials. Qualitative analyses further corroborated the quantitative findings. Scanning Electron Microscopy (SEM) images and Energy Dispersive X-ray Spectroscopy (EDX) mappings were employed to assess the morphology and elemental distribution of the recovered materials. This underscores the importance of optimizing pulse duration to balance material recovery with contamination levels.

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Outlook on Future Upscaling and Commercialization

The FREE4LIB project envisions scaling up EHF technology for broader commercial applications. Key areas of focus include:

1. Industrial Partnerships: Collaborating with battery manufacturers to integrate EHF into existing recycling infrastructures.
2. Technological Advancements: Continuing to refine the EHF process and exploring new materials to enhance efficiency.
3. Regulatory Support: Engaging with policymakers to establish regulations that favor the adoption of sustainable recycling technologies.

The work carried out on electrohydraulic fragmentation and related technologies represents a significant advancement in the field of battery recycling. By emphasizing efficiency, sustainability, and collaboration, Fraunhofer IWKS is positioning itself as a leader in developing innovative solutions that address current challenges while paving the way for a more sustainable future in resource management. The advancements in EHF, combined with effective post-treatment techniques like skimming and sieving, hold the promise of transforming the recycling landscape for lithium-ion batteries, contributing to the circular economy and securing a more sustainable supply chain for critical materials.

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Picture : Continuous electrohydraulic fragmentation (EHF) plant at Fraunhofer IWKS site in Hanau, Germany.