The second day of the RHINOCEROS M24 meeting featured the presentation of the TranSensus LCA project, delivered by Prof. Dr. Ing. Thilo Bein. This cross-collaboration initiative aimed to open cooperation activities between the two projects, focusing on the development and application of a harmonised life-cycle assessment (LCA) approach for zero-emission road transport.

Prof. Dr. Ing. Thilo Bein presented the TranSensus LCA project, coordinated by Fraunhofer and launched in January 2023. The project aims to establish a commonly accepted and applied LCA approach for zero-emission road transport while developing a framework based on European data. This initiative involves stakeholders from industry, research, standardisation bodies and the European Commission. The project’s scope could extend internationally, with coordinators planning a wider stakeholder consultation to inform further guidelines and policy recommendations.

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Potential collaboration routes between RHINOCEROS and TranSensus on LCA topics

The exchange of questions and ideas during the presentation spurred significant interest and facilitated collaboration opportunities between the two projects. The representatives of RHINOCEROS LCA work package received invitations to participate in future trainings organised by TranSensus. These workshops are designed to equip participants with advanced knowledge and skills in life-cycle assessment methodologies. By integrating the harmonised LCA approach proposed by TranSensus in the future, RHINOCEROS has the possibility to contribute to the broader goals of this coordination and support initiative and potentially influencing policy development.

Discussions about LCA raised additional questions about life-cycle costing (LCC). Although not comprised in the scope of work of TranSensus, future guidelines will include also recommendations on how to tackle LCC in common approach.  TranSensus will continue publishing reports and guidelines towards the end of this year. Among other topics, these deliverables will address:

• Modelling technology penetration in the market
• Recommendations on how to model the energy mix for sensitivity analysis
• Various use cases, RHINOCEROS being a potential candidate for this category

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When it comes to recycling lithium-ion batteries (LiBs), safety and efficiency are paramount. Classified as hazardous waste under EU legislation, spent LiBs pose significant risks, primarily due to their state-of-the-art (SoA) non-aqueous electrolytes. This complex mixture, which includes conductive salts dissolved in organic solvents and additives, is flammable, volatile, and toxic. By their very nature, the uncontrolled release of these components can harm the environment and endanger workers in recycling plants. Additionally, electrolyte residues in LiB waste streams represent a financial burden for the recycling industry since they are still classified as hazardous waste. Therefore, safely recovering the electrolyte is crucial for developing a secure recycling process.

One promising alternative to traditional methods like vacuum vaporization is supercritical carbon dioxide (ScCO₂) extraction. The easily adjustable properties and excellent mass-transfer characteristics of ScCO₂ make it potentially ideal for selectively extracting electrolyte components from LiB waste, resulting in purified extraction products. Previous research has demonstrated that non-polar electrolyte solvents like dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) can be extracted using low-density CO₂.

Recent results reported by the research team at University of Chalmers (CHA)have shown that by gradually increasing pressure and temperature conditions, more polar electrolyte components such as ethylene carbonate (EC),  and propylene carbonate (PC) can also be successfully extracted. However, selective extraction of solvents remains a challenge, requiring further thermodynamic and kinetic data to optimise the process.

Modelling the extraction behaviour allows the designing of an optimised extraction process that achieves high purity solvents. This high purity enables the recycling industry to either resell the solvents for other uses or even reuse them in battery production, making the process more sustainable and economically viable.

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Work package (WP) 6 partners, notably ECO RECYCLING (IT) team, have completed the first version of the simulations of various hydrometallurgical processes. These tools are essential for the next scaling step since they provide a first version of the material and energy balance. In addition, these simulations make it possible to estimate the time needed to complete a production cycle, to define potential bottlenecks at each step and, above all, to define the necessary equipment and their sizing in order to produce 10kg/day of battery active material.

In parallel with the process simulations, WP6 research team compiled an equipment inventory to assess assess the potential use of the facilities currently available at JGI-HYDROMETAL (BE), as part of the RHINOCEROS project. This timely inventory will help the partners to identify the additional equipment requirements necessary to properly equip the pilot plant for the scale-up process. Work is underway to best prepare the construction of the future pilot.

There is an undeclared competition for better, more efficient batteries which pushes researchers to continue developing new methods for extracting and synthesising electrodic materials.

Recovery of lithium as battery grade material

Lithium (Li) is a key component in batteries and scientists involved in the RHINOCEROS Project have been exploring ways to extract it from recycled materials from used batteries known as “black mass” (BM). But one of the challenges scientists are facing is the reduction of fluoride content in extracted Li. Researchers at KIT tested their mechanochemical process for extracting Li from various BM samples provided by partners ACC and TES. Their experiments engaging reactive milling coupled with various reactive agents aimed to reduce the fluoride content of the aqueous solution. These tests showed that using magnesium as a reactive agent yielded most promising results for Li extraction.

Progress in Lithium-Manganese battery materials and Advancements in Reduced Graphene Oxide production

Research team at Sapienza Univ. of Rome (UoS) has been making progress in developing lithium-manganese-rich materials for battery applications. These materials were produced using an integrated hydrometallurgical process, which includes the production of reduced graphene oxide and a co-precipitation method that leads to the formation of lithium-manganese-rich cathodes. The resulting cathode materials are currently undergoing extensive physicochemical and electrochemical characterizations.

For the synthesis of reduced graphene oxide, the researchers compared two methodologies and observed differences in productivity. These differences are now being investigated to determine whether they are influenced by the thermal pre-treatment of the graphite or by the role of metals present in different oxidation states. The use of mechano-chemically treated powder has demonstrated remarkable productivity, reaching approximately 80%.

Enhanced solvometallurgical processes

As evoked by its name, solvometallurgy uses solvents to extract metals. Researchers at TEC have been optimising the process, using additives as copper (Cu) or hydrogen peroxide (H₂O₂) when necessary, achieving a high recovery rate of >95%. However, the process also increased the dissolved Cu content, which required additional steps to reduce it. Researchers are now exploring methods like cementation or electrodeposition to recover and reuse the dissolved Cu. The deep eutectic solvents (DES) were already regenerated and reused, result which could bring a positive impact on the process sustainability assessment.

Direct recovery of battery materials

The Gas-Diffusion Electrocrystallisation (GDEx) technology allows the one-step recovery of metals and synthesis of new materials with high added value. In the framework of the RHINOCEROS project, the research team at VITO has been focusing on optimising the GDEx technology to achieve the selective recovery of nickel (Ni), manganese (Mn), and cobalt (Co), contained in leachates from black mass and achieved 90 % extraction of Ni, Mn and Co. This two-step GDEx process facilitated the removal of all the impurities such as Cu, Fe from the leachate solution. Using the GDEx process, VITO researchers have successfully synthesised Layered Double Hydroxide (LDH) materials and spinel-type nanostructures from the synthetic solutions. The LDH materials were lithiated and LiNi_0.8Mn_0.1Co_0.1O₂ (LNMCO811) was synthesised, which could be used as a cathode active material for lithium-ion batteries (LiBs).  The results obtained with synthetic solutions portray the potential of the method to obtain relevant active cathode materials out of leachate solutions.

Recovery of materials from low concentration waste streams

Aiming towards a zero-waste strategy for the recovery of metals from battery refining waste waters, LEITAT is working on the development and evaluation of novel polymer inclusion membranes (PIM). PIMs are a type of liquid membrane in which the liquid phase, the extractant, is held within a polymeric network. The interest in these membranes has been growing exponentially over the past few years as an alternative separation technique to conventional solvent extraction.

During the previous six months, the team at LEITAT have been investigating two types of membranes that have shown high selectivity, recovering manganese (Mn) and cobalt (Co) from mixed metal solutions. In their future research, LEITAT will use these membranes in combination to ensure increased selectivity of targeted metals.

Optimising lithium carbonate recovery

Lithium carbonate(Li₂CO₃) is another critical material for batteries, and researchers at TEC and LEITAT are working to optimise its recovery from various solutions. This involves fine-tuning the conditions for Li₂CO₃ precipitation, including the influence of pH and the presence of other cations. Tests are currently conducted with both synthetic solutions and real leachates to ensure the effectiveness of the process. Additionally, efforts are underway to automate the recovery process, which includes assembling elements for pH monitoring and CO₂ bubbling systems.

Bringing innovations to market

To bring these innovations to market, researchers are preparing to scale up their processes. This involves a selective process based on data collection, life cycle assessment (LCA) and life cycle cost (LCC) analysis, to ensure the best technological routes are chosen to be further upscaled and meet the production demands.

Researchers at University of Agder (UiA) are working on the automated sorting and dismantling of lithium-ion batteries (LIBs) that facilitates their reuse for second life applications.

During the first reporting period, UiA designed a simulator within a virtual environment, which allowed researchers to collect necessary data and parameters, and additionally identify potential bottlenecks that may occur in the actual disassembly process. Beyond collecting data without any physical experiment, the simulation environment brings the benefit of being cost- and time-efficient, allowing for safe and flexible robotic programming without disrupting the production.

According to the simulation environment that covers the entire disassembly process, from automated discharging to sorting, the entire process can run with a total duration spanning between 12 and 14 minutes. The detailed results of this activity will soon be publicly available in a new scientific paper titled addressing  the evaluation of deep reinforcement learning for job shop problems.

During the past six months, UiA researchers have constructed a virtual simulator to train the Machine Learning (ML) algorithms. Deep learning methods have already been applied for the Job Shop problem for finding the optimal disassembly sequence when the dependence matrix is known. Next development steps will entail training the algorithms to enable automatic disassembly of Electric Vehicle (EV) batteries without prior knowledge, while optimising procedures and enhancing safety.

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Author: KIT

During the third semester, researchers from KIT further studied and improved the conditions for the mechanochemical transformation of black mass (BM) into metallic black mass (MBM). Since BM supplied by ACC is already in a reduced state, they focused on reducing BM supplied by TES. This BM consists mostly of NMC (lithium nickel manganese cobalt oxides) cathode material and graphite, which was found to slow down the reaction kinetics. The reduction of the cathode active material by the metallic reducing agent result in the formation of the transition metals along with lithium oxide (Li₂O) and the oxide of the respective reducing agent, which can be monitored by X-ray diffraction.

In contrast to the previous two semesters, researchers switched from shaker mills to planetary mills, which enable control of the rotation speed and larger volumes that can be processed. Various parameters such as ball-to-sample ratio (BSR), ball size, total load and rotation speed were investigated to optimise for a short reaction time.

Main take-aways

In general, the higher the BSR, the more mechanical energy can be transferred per gram of powder which results in a more intense milling and a faster reaction; however, this limits the throughput. Larger balls, on the one hand, lead to higher kinetic energies. On the other hand, fewer balls are used to keep the BSR constant resulting in a lower collision frequency. The maximum rotation speed is lower to prevent damage to the grinding media.

With Calcium as the reducing agent, no reaction was achieved at all. An unfavorable combination of ductility and size of the calcium pieces seems to resist further size reduction, which is required for the reaction.

Aluminium has the advantage of being used as a current collector and is already present in the black mass. However, during the reaction, LiAlO₂ is formed, which is limiting the subsequent Li extraction efficiency in WP5. This problem can be avoided when magnesium is used as the reducing agent, which proved to be more reactive than aluminium but doesn’t form other lithium compounds than Li₂O.

Compared to the shaker mill, a higher reaction rate was observed in the planetary mill. Researcher from KIT achieved a complete conversion of the lithium transition metal oxide in the planetary mill within 3 h using Mg as the reducing agent. In a larger version of the mill, the required milling time increases to 8 hours. Here, further investigations are planned for the next months.

Read previous article on the pre-treatment operations: Pre-treatment operations: Reactive milling for the production of metallic black mass

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Author: KIT

Following previous work performed in work package 5, researchers from KIT further investigated the lithium (Li) extraction from black mass (BM) supplied by partners ACCUREC (ACC) and TES.

The BM provided by ACC consists of graphite, as well as transition metals such as nickel (Ni), manganese (Mn), and cobalt (Co), along with their respective oxides and impurities like copper (Cu), iron (Fe) and few fluorinated compounds. Li is present in the form of lithium carbonate (Li₂CO₃), lithium fluoride (LiF) and lithium aluminium oxide (LiAlO₂). However, breaking off lithium aluminium oxide to a soluble Li-salt and removing fluoride contamination proved to be challenging.

Previous work reported the simultaneous incorporation of fluoride ions and decomposition of LiAlO₂ using an excess of calcium hydroxide (Ca(OH)₂) at elevated temperatures.  More recent developments of the processes show improvement, especially decreasing considerably the amount of of Ca(OH)₂ , while achieving a Li extraction of 87 %. Instead of heating the suspension, it is possible to initiate the reaction by liquid-assisted grinding in a planetary mill. The results show LiAlO₂ is decomposed. However, the fluoride content is not efficiently removed.

In the BM supplied by the partner TES, most Li is present as lithium transition metal oxides (LiTMO) and a small amount of LiF. To enable Li extraction, this BM was reduced by reactive milling in Task 4.4 – Reactive milling for the production of metallic black mass (MBM). The obtained MBM consists of graphite, the metallic composite, lithium oxide and the oxidised reducing agent, along with some impurities like Fe and fluorinated compounds.

After investigating aluminium (Al) and calcium (Ca) in the previous steps, researchers at KIT performed tests to assess Li extraction using a magnesium (Mg) system, which presents various advantages, namely: avoiding, on one hand, the formation of Li salts with bad solubility, and relying on the other hand on insolubility of Mg in the high pH aqueous solution.

After aqueous extraction, researchers obtained a mixture of Li₂CO₃ and LiF. In the upcoming months, this mixture will be purified to a battery-grade material.

The Critical Raw Materials Act (CRMA), proposed by the European Commission in March 2023, was adopted by the Council one year later, on 18 March 2024, marking the last step in the decision-making procedure.

Looking back in time, less than three years ago, the raw materials was a topic exclusively tackled by ‘connaisseurs’. Today, it has become a strategic file, and the speed of its adoption shows need for action to secure a sustainable supply of critical raw materials (CRMs).

Standing at the core of the Green Deal Industrial Plan, together with the Net Zero Industry Act and the Reform of the electricity market design, the CRMA is a flagship initiative with a threefold objective: to increase and diversify the EU’s CRMs supply, to strengthen circularity, including recycling, and to support research and innovation (R&I) on resource efficiency and the development of substitutes. The bloc further consolidated this timely adoption with a set of complementary regulations and diplomatic initiatives, outlining a clear position ready to reduce reliance on third countries through export restrictions and screening for foreign direct investment across various sectors [e.g. forging strategic agreements with Chile, Greenland, Ukraine, Canada, Rwanda, and more recently Norway].

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Echoing the official communication, Commission Vice-President Valdis Dombrovskis declared for Euractiv: “Trade flows of critical raw materials are highly concentrated,” adding, “While we will continue to rely on imports, we need to massively diversify.”

The official document sets a threshold of 65% of the EU’s annual consumption of any CRM deriving from any single country. The CRMA establishes also a list of 34 critical and no less than 17 strategic raw materials considered crucial for the twin green and digital transition, as well as for defence and space industries.

In addition to the updated list of CRMs, the act introduces three targets for annual consumption of raw materials:

• 10% for local extraction
• 40% EU domestic processing threshold
• 25% of supply emanating from recycled material

These changes modifying the recycling target reflect the increasing importance of paving a circular economy model that ensures a sustainable supply of raw materials.

© visual: European Commission

Benefits of “offline programming”

Simulation environments have been widely used in robotics for demonstration and planning purposes. This typically takes place within a simulation software or any other platform that can replicate the robot’s dynamics, workspace and surrounding environment, and enable robotic programming. This replication system has proved to be cost- and time-efficient due to a series of advantages: no risk of disrupting the production by removing the robot from the production line, high flexibility allowing infinite number of configurations on a virtual model of the robot, reduced risk of equipment damage due to high predictability of malfunctions. For instance, operational industrial robots can be tested in a simulation environment before deployment. This process is often referred to as “offline programming”.

Researchers at Department of Engineering Sciences, University of Agder have been designing a simulator within a virtual environment to visualise and test various demanufacturing approaches for battery packs, allowing them to collect necessary data such as process duration, disassembly tools – all without the need of physical experiments. This innovative exploration not only streamlines data gathering but can also help identify and remove unforeseen bottlenecks in the disassembly process.

Environment configuration and use case application for battery pack demanufacturing

Using a simulation environment, known for its high-fidelity graphical capabilities, researchers at UiA were able to create a controlled virtual space ideal for visualising complex robotic processes and interactions related to demanufacturing electric vehicle (EV) batteries. The robotic cell design is decomposed across all the subtasks/segments of the disassembly process, with specific consideration to safety aspects and optimised efficiency and accessibility of robotic manipulators.

In order to study in depth and to demonstrate the efficacy of a proposed fully automated demanufacturing line, researchers at UiA meticulously recreated a virtual environment where they simulated the disassembly of a an EV battery pack. This simulation encompasses the entire process from automated discharging to the disassembly of packs into modules, subsequent characterisation, sorting, and finally, the disassembly of modules into individual cells. All elements of the simulation are animated using the simulation platform and a robotic operating system code, providing a holistic view of the potential automation within the demanufacturing process.

For this particular use case, researchers at UiA have calculated the time individually for each disassembly operation, reaching roughly between 12 and 14 minutes for the entire process.

The findings of this research that replicated the complete demanufacturing of EV LiB pack in a virtual, yet realistic industrial setting, illustrate the leverage of automated processes over conventional approaches conventionally relying on manual techniques. The simulation provides estimates for operation time for a given disassembly procedure (disassembly sequence and disassembly process). Upcoming steps will involve AI to generate and optimise the procedures. Additionally, the simulation can identify solutions to minimise human exposure to potential hazards associated with battery disassembly processes. Future in depth and multidisciplinary research is required to optimise the disassembly sequences and process in the simulated environment by training reinforcement learning agents and including a collision avoidance system, to name a few.

Ultimately, the aim of this research is to anticipate the increasing number of EV batteries that will be decommissioned soon, and to ensure a proper management of waste, while recovering all the resources available in clean mobility technologies.

Discover UiA’s previous activities

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Authors: CHA and PNO

An important component of a Li-ion battery (LiB), the electrolyte has a crucial role in the cell performance. The nonaqueous electrolyte is a multicomponent system consisting of a conductive salt, mainly LiPF₆ (Lithium hexafluorophosphate – inorganic component), organic carbonate solvents and additives.

Numerous research initiatives are dedicated to the design of the electrolyte composition, aiming to optimized performance, increased safety, lifetime and streamlined costs. However, once a LiB reaches its end-of-life (EoL) stages, the electrolyte receives less attention in the favour of the valuable metals that can be recycled from the cathode: Li, Co, Mn, Ni, Al, Cu. Moreover, due to its volatility, toxicity and high flammability, the electrolyte recycling is less studied. When ignored, the spent electrolyte reacts with water to form fluoride, leading to its uncontrolled decomposition and/or evaporation, and thus generating an imminent environmental risk. Due to its composition that includes organic solvents, the presence of residual electrolyte in the black mass is considered hazardous, and it is often a reason hampering the recycling process.

Researchers at Chalmers University (CHA) ) developed a sub- and supercritical carbon dioxide (sc-CO₂) extraction process to selectively recover the electrolyte from spent LiBs. Sc-CO₂ extraction technologies are already widely employed in the food, beverage, pharmaceutical, and cosmetic industry. In a nutshell, sc-CO₂ forms when CO₂ surpasses its critical point at 31°C and 73.8 bar pressure. In this so-called supercritical state, CO₂ demonstrates optimal mass-transfer characteristics and can be fine-tuned to alter its physicochemical characteristics by adjusting pressure and/or temperature. However, CO2 proves ineffective as a solvent for high molecular weight polymers and highly polar ionic compounds. However, the addition of a co-solvent or a modifier can significantly improve the solubility properties of sc-CO₂, making this alternative a suitable process to selectively extract LiPF₆ after solvent removal.

Researchers at CHA investigated different process parameters (pressure, temperature, extraction times) to understand their impact on the extraction behavior of different electrolyte solvents such as ethylene carbonate. Their analysis included both qualitative and quantitative results indicating the composition and the purity. Simultaneously, the research also monitored the process exhaust stream for potential formation of LiPF₆ decomposition products. The findings showed that that the non-polar electrolyte solvents like dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate were successfully extracted using low-density CO₂. The more polar electrolyte components such as ethylene carbonate and propylene carbonate were stepwise extracted by gradually increasing the system’s pressure. The developed technology is a game changer not only for electrolyte recycling but also for increased workplace and transportation safety due to removal of the flammable and hazardous substances from battery black mass. The simplicity of the processing design is an additional advantage of the technology.

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