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.

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.

More information

© Photo credit: Adobe

During the past years, the increase in the use of lithium-ion batteries (LIBs) has become more prominent. An unsurprising trend, whatsoever, due to the widespread and rapid adoption of clean mobility applications, electronic devices, and energy storage systems. Despite their undeniable environmental and social benefits, several challenges lie ahead. In 2022, global lithium demand exceeded the supply despite an 180% increase, IEA reports. Recent communications already forecast the demand of lithium (Li) is expected to soar over the next decade, with mobility accounting for the main consuming market.

The current supply of primary resources is deemed insufficient for the growing demand. Approximately 60% of today’s lithium is mined for battery-related applications, a figure that could reach 95 percent by 2030, McKinsey reports estimate. But this rapid increase in the use of LIBs in EVs will introduce a large quantity of spent batteries in the near future. The alternatives to manage spent batteries include remanufacturing, repurposing and recycling, with the latter one playing a significant role from both ecologic and economic points of view.

Current recycling processes lack selectivity in recovery control and require significant consumption of reagents and energy. The research conducted by the RHINOCEROS partners at Sapienza University of Rome (UoS), Department of Chemistry, aims to develop an electrochemical process for selective extraction of Li from electrodic powder of end-of-life (EoL) LIBs. This concept simulates the charging process of a LIB with an aqueous electrolyte and a cathode material (counter electrode) that facilitates water reduction. The hydroxyls freed by water reduction and the Li + cations deintercalated by the anode will form a LiOH solution.

Using two samples – a commercial powder, respectively one coming from EoL LIBs, and testing the delithiation process using various parametres, UoS researchers obtained:

• Li extraction of 99% from commercial powder
• Li extraction of 82% from waste powder

The lower Li extraction on EoL electrode powders compared to commercial ones is due to the presence of SuperP [a high purity and structured carbon black powder with a moderate surface area for the lithium-ion industry], which oxidises under delithiation conditions.

Discover the scientific publication

RHINOCEROS attending Shifting Economy Week

From 21 to 25 November 2023, the city of Brussels hosted the Shifting Economy Week, an annual event dedicated to showcasing transformative projects that aim to pave the way to an economy that is low-carbon, regenerative, and equally circular. The 2023 exhibitors’ line-up included, among other regional stakeholders, our partner Watt4Ever (W4E), industrial partner specialised in the development of innovative solutions for energy storage and management. W4E leveraged its presence at Shifting Economy Week to to raise awareness about the importance of circular economy principles in the context of the battery industry.

During the same event, W4E’s CEO, Aimilios Orfanos, was invited to speak at the BeCircular conference, an event dedicated to presenting concrete examples of circular economy approaches put in place by Brussels-based companies. He shared insights from W4E’s experience in developing second-life battery systems for electric vehicles, emphasising their potential benefits in terms of environmental impact and cost savings. Simultaneously, the CEO also highlighted the challenges faced by the industry in implementing circular business models, including regulatory barriers and market incentives.

RHINOCEROS at its second participation at Circular Wallonia Days

A few days after attending Shifting Economy Week, W4E represented the RHINOCEROS project at the Circular Wallonia Days, held on 13 and 14 December 2023. Centred around advancing the circularity of the batteries value chain, the event brought together stakeholders from academia, industry, and government to discuss strategies for improving the sustainability of battery production, use, and disposal. The focus topics covered recycling technologies, supply chain transparency, and policy measures to support the transition to a circular battery economy.

© Photo credits: Watt4Ever

Despite a different objective, the RHINOCEROS project partners have shown growing interest in the Digital Battery Passport, an initiative of FREE4LIB, a sister project from the Cluster Hub “Production of raw materials for batteries from European resources”. This collaboration shows our commitment to contributing to the European battery community through the exchange of knowledge and experience.

The FREE4LIB workshop had a three-fold objective, including a brief presentation of the preliminary results of the battery passport concept development, the outline of the implementation challenges and potential follow-ups of industrial scale-up, and the clear differentiation between battery second use (B2U) versus recycling. The event drew approximately 50 participants from various segments of the battery value chain, which ensured a comprehensive and multifaceted perspective of the subject matter.

The introductive session presented the FREE4LIB project, briefly highlighting past achievements and focusing mainly on the remaining activities outlined in the workplan. The following session was led by Julius Ott (industrial engineer with expertise in circular economy at Karl-Franzens-Universität Graz). During the past year, researchers at Univ. of Graz worked on finalising data collection and processing related to the development of a data model of the digital passport platform which aims to close the information gap between beginning-of-life (BoL) and end-of-life (EoL) battery lifetime. This interactive session turned out to be an appropriate opportunity for researchers at Univ. of Graz to present the outcomes of their data collection and handling, and to evaluate their relevance within the reality portrayed by the workshop attendees.

Participants, predominantly familiarised with the EU-funded battery projects, confirmed the findings reported by Univ. of Graz. However, they also raised concerns about data sharing. The outcomes of the interactive session, complementing prior research, will serve as valuable guidance for the FREE4LIB project in implementing the battery passport within their project.

Download workshop results

For additional background information on the digital passport developed by FREE4LIB, please refer to previous articles.

Part of the Cluster Hub “Production of raw materials for batteries from European resources”, the RHINOCEROS consortium received the online visit of FREE4LIB representatives during the second day of the Consortium meeting held in Gothenburg. This initiative including stakeholders involved in different European R&D initiatives goes beyond building a knowledge exchange ecosystem to address common topics related to EU-funded projects; it paves new collaboration routes and synergies aiming at driving innovations for the recycling of batteries and the production of raw materials for battery applications from primary and secondary resources available in Europe.

Represented by Julius Ott (industrial engineer with expertise in circular economy at Karl-Franzens-Universität Graz) and Pau Sanchis (senior policy officer Eurobat), the FREE4LIB presentation focused mainly on the Digital Battery passport and the relevant legislative situation at European level.

Pau Sanchis referred to the Digital Battery Passport in the context of the new regulation on batteries and waste batteries which entered into force on 17 August 2023.  According to this update, thoroughly explained in Art. 77, the battery passport should contain information “relating to the battery model and information specific to individual battery, including resulting from the use of that battery”.

“Batteries should be labelled in order to provide end-users with transparent, reliable and clear information about batteries and waste batteries. That information would enable end-users to make informed decisions when buying and discarding batteries and waste operators to appropriately treat waste batteries. Batteries should be labelled with all the necessary information concerning their main characteristics, including their capacity and the amount of certain hazardous substances present. To ensure the availability of information over time, that information should also be made available by means of QR codes which are printed or engraved on batteries or are affixed to the packaging and to the documents accompanying the battery and should respect the guidelines of ISO/IEC Standard 18004:2015. The QR code should give access to a battery’s product passport. Labels and QR codes should be accessible to persons with disabilities, in accordance with Directive (EU) 2019/882 of the European Parliament and of the Council (17).”

The policy officer emphasised the role of the standardisation process on the Battery Passport, which requires the Commission to adopt implementing decision requesting European Standardisation Organisation to develop standards in support of Ecodesign by December 2023. Standards regarding the technical design and operation of the Battery Passport are expected to complement provisions under Art. 78. According to the timeline presented in the regulation, the first application of the battery passport is expected in 2027. From 18 February 2027 onwards, “all batteries shall be marked with a QR code as described in Part C of Annex VI.

The new regulation aiming at strengthening sustainability rules for batteries and waste batteries will be supported by various secondary legislation pieces which will ensure all the requirements will be developed and implemented effectively. The QR code shall provide access to the following:

• for light means of transport (LMT) batteries, industrial batteries with a capacity greater than 2kWh and electric vehicles batteries, the battery passport in accordance with Article 77.
• for other batteries, the applicable information referred to in paragraphs 1 to 5 of this Article, the declaration of conformity referred to in Article 18, the report referred to in Article 52(3) and the information regarding the prevention and management of waste batteries laid down in Article 74(1), points (a) to (f).
• for starting, light, and ignition (SLI) batteries, the amount of cobalt, lead, lithium or nickel recovered from waste and present in active materials in the battery, calculated in accordance with Article 8.

The policy overview presentation was complemented by the technical presentation undertaken by Karl-Franzens-Universität Graz, that will develop a data model of the digital battery passport platform aiming to close the information gap between beginning-of-life (BoL) and end-of-life (EoL) battery lifetime. Relying on knowledge generated previously by Univ. of Graz, the researchers set an objective to define clear user roles and establish access to certain information. Up to this moment, the work carried out has been focusing on data collection and data handling (data points sorting) on the other side. This specific work encountered various challenges, notably the users willingness to share information, process standardisation, the variety of products, the recycling cost/revenue ratio, the dynamic development of the legislative framework, to name a few.

Learn more about the progress on the battery passport on the FREE4LIB website.

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

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.