The modified Black Mass (BM) obtained in Task 4.4 – Reactive milling for the production of metallic black mass (MBM), as well as the BM supplied by partner ACCUREC (ACC) were leached under different conditions to extract lithium (Li) salt.

The BM provided by ACC consists of graphite, as well as transition metals such as nickel (Ni), manganese (Mn), cobalt (Co), along with their respective oxides and impurities – copper (Cu), iron (Fe), and few fluorinated compounds. Li is present in the form of lithium carbonate [Li₂CO₃] and lithium aluminium oxide [LiAlO₂ ]. However, breaking off LiAlO₂ to a soluble Li-salt and removing fluoride contamination is a challenging process. To overcome this, the BM was heated with calcium hydroxide in deionised water for one hour and then filtered.

Illustrated in the next figure, LiAlO₂ decomposes during heating and transforms into insoluble calcium aluminium hydroxide. Dissolved fluoride anions are caught by Ca²⁺ ions and precipitate as calcium fluoride. The soluble part only contains Li- and Ca-salts. The latter can be transformed into calcium carbonate and removed with a second filtration step.

The second BM from partner TES, obtained after ball milling, consists of graphite, the metallic composite, lithium oxide and the oxidized reducing agent, along with some impurities like Fe and fluorinated compounds.

Lithium extraction after ball milling

In the aluminium system, the extraction of lithium salt poses certain challenges. Due to the tendency of residual aluminium powder to ignite when in contact with air, this requires cautious handling. During milling lithium aluminium oxide is formed, and in the basic solution, a significant amount of aluminium hydroxide dissolves and reacts with lithium hydroxide and CO₂, resulting in the formation of a poorly soluble compound called LACHH. To address this problem, the suspension is heated to 90°C to reinforce the reaction between aluminium hydroxide and lithium hydroxide. The LACHH formed can be decomposed at 350°C into insoluble aluminium oxide and soluble lithium carbonate, which can be separated through filtration.

Lithium extraction in the calcium system, on the other hand, is a relatively straightforward process. The milled powder shows low reactivity towards both oxygen and water. Scientists successfully extracted 98% of lithium from the black mass; however, calcium hydroxide was also dissolved in the process. Subsequent purification steps led to the isolation of lithium carbonate with a purity of 93% in a yield of 75%. The main impurities are shown in the figure displayed below.

In the upcoming months, researchers will work to improve the leaching conditions towards a lower reagent and water consumption, while obtaining a higher purity of resulting lithium salt and lower lithium loses during purification steps.

 

During the second semester, researchers from KIT further studied and improved the conditions for the mechanochemical transformation of Black Mass (BM). With the BM supplied by ACC is already in a reduced state, the focus now shifts towards reducing the BM provided by partner TES.

This BM consists mostly of nickel-manganese-cobalt (NMC) cathode material and graphite, and it was found to cause a longer reaction time. It is expected that the graphite exfoliates during milling and creates thin protective layers around NMC particles and the reducing agent, slowing down the reaction kinetics.

Using variations of milling parameters like ball-to-sample ratio or the type and amount of reducing agent, researchers optimised the process towards the fastest kinetics. During the investigation, no intermediate reduction to transition metal oxides in lower oxidation states was observed. However, the full reduction of the respective part to the metallic composite occurred.

The operation took place in a shaker mill, and it requested an excess of 3.3 equivalents of Aluminium (Al) towards NMC was required to attain a complete reduction within a reasonable time. This transformation was accompanied by the formation of aluminium carbide and the presence of residual fine aluminium powder which caused a  self-ignition hazard when the milled powder came into contact with air.

In contrast, when using calcium as a reactive agent, researchers observed a fast reaction but they also reported a strong dependency of reaction kinetics on calcium size. The hazard of self-ignition when exposed to air was limited in this case by using stoichiometric amounts.

In addition, the research team has been conducting preliminary experiments for the scale-up process using a planetary mill. It was observed that the choice of the milling type has a significant impact on the reaction kinetics. Attempts to crush calcium pieces proved to be unsuccessful, therefore not initiating any reaction. However, when using aluminium, reactions occurred much faster.

In the months ahead, the research team working in WP4 will continue to investigate the milling parameters for the planetary mill.

Find out more information about the activities developed in WP4 in the article Reactive milling for the production of metallic black mass (MBM) – Rhinoceros project (rhinoceros-project.eu)

Read more about the black mass leaching operations in the article Materials extraction and direct routes for the synthesis of electrode materials: Recovery of Lithium as battery grade materials

Three dimensional (3D) Scanning of Battery Packs

Following the manual dismantling of various battery packs during the first six months of project, researchers at University of Agder (UiA) have developed a semi-automated process to address the diverse nature of battery packs. Their advanced robotic system can estimate the size of individual components of a battery pack. Afterwards, using different angles, it identifies optimal locations to capture precisely 3D images of these components, thus ensuring no detail is missed through this comprehensive scanning.

Using different perspectives, this thorough scanning process is further translated into a list of point clouds. Applying sophisticated algorithms,  these point clouds are later combined and merged into a solid mesh component. This process is repeated individually for each new component which needs to be scanned.

Beyond geometric characteristics

While geometric characteristics are important, they provide even greater value when combined with other physical attributes and interconnection data of the components. The researchers have successfully documented these details, resulting in a rich digital repository of the battery pack. With the establishment of this detailed digital repository, the focus is now shifting towards its applications, where the primary goal is to automate the disassembly sequences.

Simultaneously, the team is also focusing on the automatic characterisation of battery packs and modules. Significant efforts are channeled towards creating a robust digital simulator, which will serve as a platform for training and rigorous testing of the disassembly planner – currently under development.

Innovation in disassembly tools

At the same time, the research team involved in work package 3 have been working on improving the disassembly operations tools. The results reported positive feedback, with several tools already successfully  tested in lab environment. This is a significant step towards the fully automated disassembly process.

A noteworthy development is the automation of the non-destructive disconnection of cables. This procedure is essential as it stands as the second most frequent operation in battery pack disassembly, just after the unscrewing operation.

You can read more about previous activities developed in work package 3 in the article ‘Manual dismantling of a battery pack‘.

On Monday, 10 July 2023, the Council of the European Union adopted a new regulation that strengthens sustainability rules for batteries and waste batteries. This regulation covers the entire life cycle of batteries, ensuring their safety, sustainability and competitiveness from production to reuse and recycling.

Read the official press release

Recognising the vital role batteries play in the decarbonisation process and the transition towards zero-emission mobility, Teresa Ribera, Spanish Minister for the Ecological Transition reinforced the Presidency’s commitment to supporting comprehensive regulation encompassing all types of batteries. This includes waste portable batteries, electric vehicle batteries, industrial batteries, starting, lightning and ignition (SLI) batteries primarily used in vehicles and machinery, as well as batteries for light means of transport like electric bikes, e-mopeds, and e-scooters.

“At the same time end-of-life batteries contain many valuable resources and we must be able to reuse those critical raw materials instead of relying on third countries for supplies. The new rules will promote the competitiveness of European industry and ensure new batteries are sustainable and contribute to the green transition.”

| Teresa Ribera, Spanish Minister for the Ecological Transition

To foster a circular economy, the regulation establishes requirements for the end-of-life phase, including collection targets and obligations, material recovery targets, and extended producer responsibility. Dedicated collection objectives for waste batteries used in light means of transport will be implemented, aiming at 51% by the end of 2028, respectively 61% by the end of 2031. Furthermore, the regulation sets mandatory minimum levels of recycled content for industrial batteries, SLI batteries and electric vehicle batteries. The following initial values have been established:

• 16% for cobalt
• 85% for lead
• 6% for lithium
• 6% for nickel

Additionally, batteries will also be required to hold documentation proving their recycled content.

To improve the functioning of the internal market for batteries and ensure fair competition, the regulation introduces safety, sustainability, and labelling requirements. It includes provisions for battery labelling and information disclosure, including details on battery components and recycled content. Additionally, an electronic “battery passport” and a QR code will be implemented to enhance traceability and transparency. These labelling requirements will take effect by 2026, while the QR code implementation is expected by 2027, providing member states and manufacturers with ample time to prepare.

This new regulation aims to mitigate environmental and social impacts throughout the battery’s life cycle. By establishing strict due diligence rules for operators, the EU is ensuring operators are bound to verify the source of raw materials used for batteries placed on the market. However, the regulation provides for an exemption for SMEs from the due diligence rules.

After its signature by the Council and the European parliament, the new regulation will be published in the EU’s Official Journal, expecting to enter into force 20 days after.

RHINOCEROS project in the current legislative framework

Launched in 2022, the RHINOCEROS project fits within the current framework recently adopted by the Council of Europe under the Spanish Presidency. Designed to support the raw materials supply, the RHINOCEROS project will demonstrate a smart sorting and dismantling robot at TRL6, enabling the automation of a battery repurposing production line. When direct reuse and repurposing of batteries is not possible, RHINOCEROS will investigate several ground-breaking circular recycling routes aiming at the recovery of all materials present in LIBs (e.g., metals, graphite, fluorinated compounds, electrolytes, polymers, and active materials).

A first set of conclusions stemming from the research of our partners generated a database and the parameters for module selection, which will further facilitate the development of electric vehicles 2nd life batteries.

Read more in the article “Acceptance criteria and guidelines for 2nd life prone LIBs” 

The infographic can be accessed on the Council of the European Union’s website using this link.

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. 

Work during the first six months has focused on the evaluation of different extractants for the target metals: lithium, manganese, cobalt and nickel. Researchers established a liquid-liquid extraction protocol based on two different processes in which the target metal is extracted and recovered separately. During the extraction step, a specific carrier compound selective towards the target metal separates an amount of it from a feed metal solution. The recovery of the metal takes place in the second process, where a stripping solution is employed to recover the metal previously extracted through the carrier. Initial PIMs containing the most efficient extractants have been prepared, characterised and are currently evaluated. The featured image depicts the continuous procedure used to test the synthesised PIMs.

The current industrial pre-treatment and downstream processes (e.g., pyrolysis, calcination, etc.) are still inefficient and have significant limitations. Plastics and electrolytes sacrificed in the initial stages of the recycling process are overlooked when it comes to their recovery. Within the RHINOCEROS project, Chalmers University [CHA] is working on recycling of ignored content of the LIBs waste, electrolyte and polymeric materials by developing an innovative process based on Supercritical Carbon Dioxide (sc-CO₂) technology. 

Due to its environmental friendliness, non-toxic, low cost and straightforward processing features, the sc-CO₂ technology has been attracting both scientific and industrial interest. With consistent leverage over other processes, sc-CO₂ technology is already widely used in various industries including food, cosmetic and pharmaceutical industries [i.e., to decaffeinate coffee or tea, extract vegetable oils etc.] Although it has many applications, its use in battery recycling was recently discovered and the Chalmers research group is one of the pioneers in this field. 

Within the project’s framework, CHA researchers are targeting the development of the sc-CO2 extraction process which will selectively recycle the electrolyte and the polymeric material from the LiB waste. The electrolyte, binder, and separator will be recycled in subsequent steps and purified to reuse in the battery industry. For this purpose, several critical process parameters such as pressure and temperature are investigated to achieve high recycling efficiencies under feasible conditions. 

Electrolyte recovery

The electrolyte in the LiB is a complex system usually composed of a conductive salt dissolved in a matrix of various solvents and additives. The most recent results reported by CHA on sub- and sc-CO₂ research show that at low pressure and temperature conditions, the non-polar electrolyte components (almost 66% of the electrolyte) were selectively recovered without the generation of toxic gas emissions, which are typically generated by thermal recovery processes originated by the decomposition of the thermally unstable conductive salt.

In this recycling step, the polar electrolyte components are left in the sample as residues and a subsequent recycling step using suitable cosolvent is required for their selective extraction. During the upcoming phases, researchers will aim to recover the electrolyte completely, including conductive salt and solvents. 

In this recycling step, the polar electrolyte components are left in the sample as residues and a subsequent recycling step using suitable cosolvent is required for their selective extraction. During the upcoming phases, researchers will aim to recover the electrolyte completely, including conductive salt and solvents. 

The selection of the co-solvent is critically important not only for effective recycling but also for the sustainability and the feasibility of the developed processes. To assess the suitability of the sc-CO₂ process, its environmental impact and economic competitiveness, CHA researchers explored also other solvents, which allowed them to select the most promising candidates for future research.  

In the upcoming months, CHA will study the effects of co-solvent modified sc-CO₂ system parameters on the recycling efficiency of PVDF and the structural properties of the recycled material. Researchers will carry out intensive characterisation studies to clarify the changes in the material structure, to determine the quality, and to optimise the process to reach the reusability goal. 

During the first six months, University of Adger [UiA] received three battery packs (out of the five planned) and manually disassembled them, opening for further analysis. In the future, this activity will feed a digital repository as promised in the first delivery of Work package 3. 

For each battery pack, the analysis includes: 

• a precedence graph informing how components are connected, which, in the upcoming steps, will help determine the best order to dismantle these components automatically.   

• an Excel table listing the characteristics of each type of component other than geometrical characteristics: number of items, mass, material, or other specific features.  
• 3D scanning in the form of point clouds (pcls) to provide information on the geometry and texture of the components constituting the different battery packs. After testing several hardware and algorithms, two of them have been selected.  

In parallel, several of the main important tools have already been identified based on the manual disassembly of these three battery packs, and a tool changer is under development. End effectors (tools) will be able to be changed quickly, including their connection to their power source (electric and/or pneumatic) and their signals. 

In addition, the disconnection of power and signal cables using non-destructive methods – operation identified as critical, has been investigated and currently, a concept is prototyped and evaluated. The main challenge is to design a tool that “fits them all”. Additional activities carried out within WP3 have investigated different sorting (characterisation) methods, based on temperature, mass loss, and other flaws, such as deformations, leakage, trace of heat damages.  

Safety has also been an important part of the work completed within WP3 during the first six months. A complete monitoring system and a set of safety measures to be followed during the scheduled demanufacturing (discharge, sorting and disassembly) activities have been established.  

During February, when the researchers started examining the available methods for automatic task planning using search algorithms and/or reinforcement learning, the robotic system adaptability was discussed. In anticipation of the implementation and testing phases of these adaptive robotic methods, thorough battery knowledge stored within the digital repository must first be developed.

 

Focusing on mechanochemical (MC) processing, the chemical transformation of the black masses (BMs) supplied by partners ACCUREC and TES, is planned to be carried out within Work package 4. 

Before MC processing, the black masses were analysed using a combination of different analytical techniques. Both quantitative and qualitative analysis were undertaken to determine the Lithium and transition metals yield of the developing recycling process. 

Using different reducing agents such as Al, Ca, and their mixtures, researchers carried out preliminary investigations of the MC processing of BMs. Within this task, different aspects, such as the role of the ball milling conditions, the ball milling time, presence of other nonreactive components, and nature of the reducing material were investigated. The analysis led to the conclusion that the kinetics of the MC-induced reduction reaction is sensitive to multiple processing parameters, as shown in the featured image: 

The upcoming research will focus on improving the reduction reaction kinetics and eliminating the possible safety hazards of fine powder materials. Once finalised, this work will determine the optimal ball milling conditions to be scaled up. 

Recovery of Lithium as battery grade materials

The process described in Task 4.4 leads to the chemical transformation of the black masses (BMs) into ferromagnetic Co-, Ni- and Mn-containing products, which will be separated from other by-products. Lithium will be extracted from the rest of the solid products in the subsequent aqueous leaching process to be further transformed into battery-grade lithium carbonate (Li₂CO₃) salt. 

Within the M1-M6 period, aqueous leaching of the ball-milled samples using Al and Ca as reducing agents (RA) was carried out. At a preliminary stage of investigations, researchers noticed the resulted Li₂CO₃ materials presented small amount of impurities. 

To increase the yield of lithium recycling, in the upcoming period, the research work will target the improvement of the leaching conditions and the purification process.  

Within Work package 2 – Selection, characterisation and supply, partners Watt4Ever [W4E] and Accurec [ACC] assembled the database and the parameters for module selection, which will further facilitate streamline the development of electric vehicles (EV) 2nd life batteries.  

The criteria were selected based on the 2nd life partner input and were adapted at module level. Partners generated a database using a sample of 200 commercial and passenger vehicles grouped in the following categories: Battery Hybrid Electric Vehicle (BEV), Mild Hybrid Electric Vehicle (MHEV) and Plug in Hybrid Vehicle (PHEV). The input received contributed to the identification of the required acceptance criteria that will help select the best modules for 2nd life Battery Energy Storage System (BESS).  

Selection criteria

The database of 200 BEV/PHEV/MHEV batteries and their characteristics, including a summary of technical information for each model, has been generated. Due to the mechanical, technical and software challenges that need to be overcome for efficient module integration in deployable LV and HV BESS, the database includes the following parameters as criteria for 2nd life applications: size, capacity, Cell Management Unit (CMU), casing and cell configuration. The chosen criteria should improve the security of the dismantling process and facilitate access to the module level for each battery pack. Simultaneously, these parameters will simplify the integration of 2nd life modules in battery energy storage or other systems.

Mechanical design criteria	Electrical design criteria
Physical Properties	Cell configuration
Capacity	Casing
	BMS/CMU

Mechanical design criteria 

For 2nd life applications, module level parameters are the ones that give insight on the desirability. First set of parameters are the Physical Properties. Second life integrators already have knowledge of module integration and have specific designs to accommodate the battery modules, if the module sizing is the commonly used roughly the size of a shoe box 350*150*120 mm, it already makes the integration a lot easier, faster and cheaper. By adding Capacity, power density can be calculated, and thus the technical design can be improved to maximise the capacity of the system. 

Electrical design criteria 

Cell configuration give an insight in to the voltage of the module, but also allows to wonder about the possible Battery Management System (BMS) use in the battery. Casing protects the cells from puncture, grinding, shorting out, but most importantly, expansion. With regards to BMS,/CMU, on various cases, partners noticed that OEMs integrate internal CMU on the module level, which can facilitate their use for second life applications. On the contrary, in cases where no CMU is available, one needs to be provided by the OEM or 3rd party.  

Module acceptance criteria for low voltage (LV) 48V systems

This design would allow to accommodate shoebox size modules from different OEM, while also keeping the same design of the box with small adjustments.

Mechanical design criteria

• Casing– Open top or Alu Jacket 
• Size: 350*150*120 mm ± 100 mm on all axis 
• CMU: External multimodule, external single module or internal and all can be reused if OEM CMU unit communications gateway is possible. 
• Cell amount: 3s-12s 
• Voltage: 10V-30V 
• Chemistry: NMC with risk mitigation or LFP

Module acceptance criteria for high voltage (HV) system 

For HV battery energy storage system, modules with higher voltage are prioritised, due to their capacity to save time and budget otherwise spent on wiring and building expenses.  External CMU from 3rd party is the preferred solution to internal CMU, as it minimises any interference and bug risks with the Energy Management System.  to be used to minimize any interference and bug risks with the Energy Management System.  

• Size: >350*150*120 mm ± 100 mm on all axis 
• Cell amount: 12s-30s 
• Voltage: 40V-100V

 

TECNALIA [TEC] has actively undertaken both the coordination tasks and the experimental activities that correspond to the solvometallurgical treatment of the received black masses. Firstly, the coordination of the project started with the preparation of the kick-off meeting, in which the entire Consortium assembled in San Sebastián (Basque Country – Spain) and comprises administration and management to ensure an efficient development of RHINOCEROS project. 

Also, the experimental section concerning the critical materials extraction from the received black masses from spent batteries started out after receiving the samples from partners ACCUREC [ACC] and KIT.  

After characterisation, TEC performed a first round of tests to these samples using a solvometallurgical route and assessing pre-treatment effect on the process. In parallel, State of Art is analysed for different relevant solvometallurgical systems aiming lithium recovery. New batches of experiments will be performed for process optimisation and new tests will also be performed when further black mass samples are received.