Recycling Of Li-ion Batteries Research Articles

Addressing the Reuse of Deep Eutectic Solvents in Li-ion Battery Recycling: Insights Into Dissolution Mechanism, Metal Recovery, Regeneration and Decomposition.

Deep eutectic solvents (DESs) have garnered attention in Li-ion battery (LIB) recycling due to their declared eco-friendly attributes and adjustable metal dissolution selectivity, offering a promising avenue for recycling processes. However, DESs currently lack competitiveness compared to mineral acids, commonly used in industrial-scale LIB recycling. Current research primarily focuses on optimizing DES formulation and experimental conditions to maximize metal dissolution yields in standalone leaching experiments. While achieving yields comparable to traditional leaching systems is important, extensive DES reuse is vital for overall recycling feasibility. To achieve this, evaluating the metal dissolution mechanism can assist in estimating DES consumption rates and assessing process makeup stream costs. The selection of appropriate metal recovery and DES regeneration strategies is essential to enable subsequent reuse over multiple cycles. Finally, decomposition of DES components should be avoided throughout the designed recycling process, as by-products can impact leaching efficiency and compromise the safety and environmental friendliness of DES. In this review, these aspects are emphasized with the aim of directing research efforts away from simply pursuing the maximization of metal dissolution efficiency, towards a broader view focusing on the application of DES beyond the laboratory scale.

Circular And Sustainable: Evaluating Lithium-Ion Battery Recycling using a Combined Statistical Entropy and Life Cycle Assessment Methodology.

While there has been a growing interest on the concept of Circular Economy (CE), its correlation with sustainability remains controversial. In this work, the combination of Statistical Entropy Analysis (SEA) and Life Cycle Assessment (LCA) is proposed as a new methodology to evaluate recycling processes from the perspective of materials circularity and environmental impacts using a Li-ion battery recycling process as a case study. This work addresses the need of quantitative circularity indicators, as SEA evaluates the concentration of materials at a systems level, while LCA measures the environmental impact of recycling processes in comparison with virgin raw materials production. It was found that process optimization points can be found by simultaneously accounting for materials recovery and the LCA categories of global warming potential, ozone depletion and mineral resource scarcity. Furthermore, a strong correlation was found for the first time between the recovery of critical elements and the environmental impact of raw materials production. The proposed methodology thus offers a robust analysis of a product lifecycle that aids in its design and optimization from the CE perspective.

Glutamate Leaching of Spent Lithium-Ion Battery Cathode in Weak Acidic-Neutral Condition: New Insight on Kinetics and Dissolution Mechanism

ABSTRACT Organic acid leaching receives less attention than inorganic acids for Li-ion battery recycling process at the industrial scale due to the high consumption rate of the acids as leaching reagents. This paper reports an effective leaching of cobalt (Co) and lithium (Li) from spent battery cathode using low concentration of monosodium glutamate as lixiviants. More than 95% of Co and Li could be dissolved at leaching conditions MSG 0.1 M (18 g/L), pH 5, sodium sulfite 0.5 M as reductant, pulp density 20 g/L, room temperature and leaching time 6 h. Increasing the temperature to 80°C sped up the leaching process, where maximum recovery could be attained within 1 h. pH played a major role in the leaching efficiency (effective range pH 4–6). pH lower than 4 led to neutral and cationic glutamate species, which were ineffective in attracting cobalt ion. pH higher than 6 initiated the surface passivation by Co(OH)2. In the absence of a passivation layer, cobalt dissolution mechanism followed the chemical reaction-controlled model, while in the presence of the layer, the mechanism switched to diffusion through product layer. Kinetic studies demonstrated that aside from pH, the formation of passivation layer was hypothetically regulated by adjusting the other leaching parameters. Aside from the observation on kinetic study, the proposed leaching mechanism was supported by characterization (particle size analysis, SEM-EDS, FT-IR) results.

Characterisation of the Grain Morphology of Artificial Minerals (EnAMs) in Lithium Slags by Correlating Multi-Dimensional 2D and 3D Methods

Slags from the metallurgical recycling process are an important source of resources classified as critical elements by the EU. One example is lithium from Li-ion battery recycling. In this context, the thermodynamic properties of the recycled component system play a significant role in the formation of the Li-bearing phases in the slag, in this case, LiAlO2. LiAlO2 crystal formation could be engineered and result in varying sizes and occurrences by different metallurgical processing conditions. This study uses pure ingredients to provide a synthetic model material which can be used to generate the valuable phase in the slag, or so-called engineered artificial minerals (EnAMs). The aim is to investigate the crystallisation of LiAlO2 as an EnAM by controlling the cooling conditions of the model slag to optimise the EnAM formed during crystallisation. Characterisation of the EnAMs is an important step before further mechanically processing the material to recover the valuable element Li, the Li-bearing species, respectively. Investigations are conducted using powder X-ray diffraction (XRD), X-ray fluorescence (µXRF), and X-ray Computer Tomography (XCT) on two different artificial lithium slags from MnO-Al2O3-SiO2-CaO systems with different cooling temperature gradients. The result shows the different EnAM morphology along the height of the slag, which is formed under different slag production conditions in a semi-pilot scale experiment of 5 kg. Based on the different EnAM morphologies, three defined qualities of the EnAM are identified: granular, dendritic, and irregular-shape EnAM.

Spectral Characterization of Battery Components from Li-Ion Battery Recycling Processes

Considering the increasing demand for Li-ion batteries, there is a need for sophisticated recycling strategies with both high recovery rates and low costs. Applying optical sensors for automating component detection is a very promising approach because of the non-contact, real-time process monitoring and the potential for complete digitization of mechanical sorting processes. In this work, mm-scale particles from shredded end-of-life Li-ion batteries are investigated by five different reflectance sensors, and a range from the visible to long-wave infrared is covered to determine the ideal detection window for major component identification as relevant input signals to sorting technologies. Based on the characterization, a spectral library including Al, Cu, separator foil, inlay foil, and plastic splinters was created, and the visible to near-infrared range (400–1000 nm) was identified as the most suitable spectral range to reliably discriminate between Al, Cu, and other battery components in the recycling material stream of interest. The evaluation of the different sensor types outlines that only imaging sensors meet the requirements of recycling stream monitoring and can deliver sufficient signal quality for subsequent mechanical sorting controls. Requirements for the setup parameters were discussed leading to the setup recommendation of a fast snapshot camera with a sufficiently high spectral resolution and signal-to-noise ratio.

Toward Sustainable All Solid-State Li-Metal Batteries: Perspectives on Battery Technology and Recycling Processes.

Lithium (Li)-based batteries are gradually evolving from the liquid to the solid state in terms of safety and energy density, where all solid-state Li-metal batteries (ASSLMBs) are considered the most promising candidates. This is demonstrated by the Bluecar electric vehicle produced by the Bolloré Group, which is utilized in car-sharing services in several cities worldwide. Despite impressive progress in the development of ASSLMBs, their avenues for recycling them remain underexplored, and combined with the current explosion of spent Li-ion batteries, they should attract widespread interest from academia and industry. Here, the potential challenges of recycling ASSLMBs as compared to Li-ion batteries are analyzed and the current progress and prospects for recycling ASSLMBs are summarized and analyzed. Drawing on the lessons learned from Li-ion battery recycling, it is important to design sustainable recycling technologies before ASSLMBs gain widespread market adoption. A battery-recycling-oriented design is also highlighted for ASSLMBs to promote the recycling rate and maximize profitability. Finally, future research directions, challenges, and prospects are outlined to provide strategies for achieving sustainable development of ASSLMBs.

A multi-dimensional indicator for material and energy circularity: Proof-of-concept of exentropy in Li-ion battery recycling

Recycling processes are an important stage in the raw material life cycle, as it enables the transition from a linear economy into a circular one. However, the currently available indicators of productivity in recycling technologies respond to the needs of a linear economy. In this work, a parameter called "exentropy" is proposed, offering the possibility to simultaneously account for mass preservation and the energy efficiency of transformative stages. As a proof-of-concept of this indicator, the analysis of a lithium-ion battery recycling process under various concentrations of a leaching reagent (i.e., 0.1M, 1M, and 2M) is presented. It is shown that, when the energy or mass dimensions are considered independently, the processes considered optimal may have conflicting characteristics. In contrast, the multi-dimensional analysis identified the process option offering the best compromise for both material and energy preservation, an aspect closer to the goals of the circular economy.

Optimizing pH conditions for impurity removal in closed-loop Li-ion battery recycling

The closed-loop recycling or resynthesis of spent cathode active materials is an emerging hydrometallurgy-based Li-ion battery (LIB) recycling approach. The conventional acidic leaching process generates various impurities in addition to the constituent elements of Ni, Co, Mn, and Li from spent Li[Ni1-x-yCoxMny]O2 (NCM) cathode active materials. It is well known that even a trace amount of these impurities in resynthesized cathode active materials can affect the LIB performance significantly. Therefore, this study aims at investigating the effects of impurities on the physicochemical and electrochemical characteristics of resynthesized NCM by varying pH conditions during the purification of the LIB leachate. After the purification process where the pH is raised from 1.9 to 6.5, Al, Cu, and Zn are completely removed and other impurities including Fe, Mg, Ca, Li, and Na mostly or partially remain in the leachate. The physicochemical properties and LIB performance of resynthesized NCM at different pH conditions are obtained by various analytical techniques. The composition of leachate and cathode active materials is correlated with the initial discharge capacity, rate capability, and cyclability. Resynthesized NCM from the purified leachate shows a similar initial discharge capacity to pristine NCM. While the purification condition at a high pH aggravates the rate capability, the cyclability of resynthesized NCM is enhanced. This established correlation between the pH condition for the impurity removal in the LIB leachate and the LIB performance of resynthesized NCM would trigger the successful implementation of the closed-loop recycling of spent cathode active materials.

Solvent-Based Electrode Recovery for Direct Recycling of Li-Ion Batteries

The surging demand for Li-ion batteries (LIBs) in electric vehicles and consumer electronics drives the enormous expansion of cell manufacturing globally, resulting in a significant amount of manufacturing scraps and vast stockpiles of spent LIBs in near future. Recycling those waste LIBs and reintegrating the recovered materials into the battery supply chain are becoming critical to build a sustainable battery ecosystem. Cathode active materials (e.g., LiCoO2, NCA, NMC) and anode active materials (e.g., graphite) are tightly adhered to metal current collectors (Al and Cu) through organic binders (e.g., PVDF). Separation of those electrode materials from metal foils is challenging yet an enabling step for the direct recycling of LIBs. In this talk, a simple yet efficient solvent-based recovery process for delaminating electrode films from metal foils will be presented. Because of the absence of harsh chemicals, the recovered electrode films and metal foils are battery grade and free of damage in terms of physical and chemical properties. Additionally, reintroducing the recovered electrode materials into a new loop of cell manufacturing will be discussed. This environmentally friendly and cost-effective separation technique not only presents a closed-loop recycling approach but also greatly advances battery recycling into a new paradigm.

Hydrogen Reduction of LiCoO2 Cathode Material: Thermodynamic Analysis, Microstructure, and Mechanisms

Hydrogen is an alternative reductant to replace carbon for the production of metals. Reduction by hydrogen has advantages compared to carbothermic reduction, such as faster reaction rate and cleaner by-product (water vapor). This study investigated the application of hydrogen reduction for recycling and recovering cobalt and lithium from Li-ion battery cathode material (LiCoO2). The study consisted of thermodynamic simulations of the reactions and microstructure evolution analysis from experimental work to propose mechanisms of the reduction process. The thermodynamic assessment predicted that metallic Co could be generated from 400 °C and was stable up to 1200 °C, but strongly dependent on the molar amount of H2. The final experimental reduction products of lithium and cobalt were found to vary and consisted of Li2O, LiOH, Li2O2 and Co, CoO, Co3O4, respectively. The experimental work revealed that the overall reduction mechanism is uniquely characterized by the reduction temperature. The temperature range of 800 °C to 900 °C offered more benefit as Co could be generated as a larger mass indicating a more progressive reduction. The data and information obtained can help optimize the parameters in the recycling of Li-ion batteries.

Emerging and Recycling of Li-Ion Batteries to Aid in Energy Storage, A Review

The global population has increased over time, therefore the need for sufficient energy has risen. However, many countries depend on nonrenewable resources for daily usage. Nonrenewable resources take years to produce and sources are limited for generations to come. Apart from that, storing and energy distribution from nonrenewable energy production has caused environmental degradation over the years. Hence, many researchers have been actively participating in the development of energy storage devices for renewable resources using batteries. For this purpose, the lithium-ion battery is one of the best known storage devices due to its properties such as high power and high energy density in comparison with other conventional batteries. In addition, for the fabrication of Li-ion batteries, there are different types of cell designs including cylindrical, prismatic, and pouch cells. The development of Li-ion battery technology, the different widely used cathode and anode materials, and the benefits and drawbacks of each in relation to the most appropriate application were all thoroughly studied in this work. The electrochemical processes that underlie battery technologies were presented in detail and substantiated by current safety concerns regarding batteries. Furthermore, this review collected the most recent and current LIB recycling technologies and covered the three main LIB recycling technologies. The three recycling techniques—pyrometallurgical, hydrometallurgical, and direct recycling—have been the subject of intense research and development. The recovery of valuable metals is the primary goal of most recycling processes. The growth in the number of used LIBs creates a business opportunity to recover and recycle different battery parts as daily LIB consumption rises dramatically.

Supercritical carbon dioxide technology in synthesis, modification, and recycling of battery materials

AbstractFor pursuing the ambitious goals in the burgeoning electric vehicles, portable electronic devices, and energy storage sectors, Li‐ion batteries (LIBs) are considered as one of the most promising electrochemical power sources because of their high energy density and moderate cost. Particularly, the improvement of battery materials and recycling of spent LIBs are receiving great attention since the sustainable approaches for the synthesis, modification, and recycling of battery materials are the crucial factors to the successful large‐scale implementation of LIBs. In this regard, supercritical carbon dioxide (SC‐CO2), which possesses many merits, such as environmentally friendly, low‐cost, individual chemical environment, and especially its unique physical properties, has been employed as solvent and reaction medium in the synthesis and modification of diverse functional materials. In this review, we mainly aim at compiling the applications of SC‐CO2 technology in the synthesis and modification of electrode materials as well as the recycling of LIBs. First, the unique properties and principles of SC‐CO2 technology are highlighted. Second, the latest progresses of the electrode materials design and recycling with the assistance of SC‐CO2 technique are summarized. Finally, the challenges, future directions, and perspectives on the design and development of battery materials and battery recycling by SC‐CO2 technology are proposed.

Recycling of Li-Ion Batteries from Industrial Processing: Upscaled Hydrometallurgical Treatment and Recovery of High Purity Manganese by Solvent Extraction

ABSTRACT Manganese plays a central role in lithium-ion batteries (LIBs) but its recycling is rarely addressed when compared to other valuable metals present in LIBs, such as Co and Ni. Thus, the main goal of this work was to study and achieve the separation of Mn from Co and Ni by solvent extraction from a leachate obtained from LIBs using hydrochloric acid in an upscaled reactor, which is an innovative aspect of this work. The results confirmed the high selectivity of D2EHPA towards Mn, which could be completely extracted in two stages (0.5 M D2EHPA at pH 2.5). The main co-extracted metals were Al, Cu and Co, but with lower concentrations than Mn. The behavior of minor impurities such as Zn and Mg was also monitored. Scrubbing using manganese chloride was crucial to remove impurities from the loaded organic and prevent their presence in the stripping product, and high O:A ratios negatively affected the scrubbing efficiency. Keeping the concentration of HCl up to 0.5 M in the stripping stage helped to limit the stripping of impurities. Manganese oxide was precipitated as a product with 99.5% purity (with traces of Zn, Cu and Co), which could be reused in the battery value chain.

Recovery and Recycling of Valuable Metals from Spent Lithium-Ion Batteries: A Comprehensive Review and Analysis

The recycling of spent lithium-ion batteries (Li-ion Batteries) has drawn a lot of interest in recent years in response to the rising demand for the corresponding high-value metals and materials and the mounting concern emanating from the detrimental environmental effects imposed by the conventional disposal of solid battery waste. Numerous studies have been conducted on the topic of recycling used Li-ion batteries to produce either battery materials or specific chemical, metal or metal-based compounds. Physical pre-treatment is typically used to separate waste materials into various streams, facilitating the effective recovery of components in subsequent processing. In order to further prepare the recovered materials or compounds by applying the principles of materials chemistry and engineering, a metallurgical process is then utilized to extract and isolate pure metals or separate contaminants from a particular waste stream. In this review, the current state of spent Li-ion battery recycling is outlined, reviewed, and analyzed in the context of the entire recycling process, with a particular emphasis on hydrometallurgy; however, electrometallurgy and pyrometallurgy are also comprehensively reviewed. In addition to the comprehensive review of various hydrometallurgical processes, including alkaline leaching, acidic leaching, solvent (liquid-liquid) extraction, and chemical precipitation, a critical analysis of the current obstacles to process optimization during Li-ion battery recycling is also conducted. Moreover, the energy-intensive nature of discussed recycling process routes is also assessed and addressed. This study is anticipated to offer recommendations for enhancing wasted Li-ion battery recycling, and the field can be further explored for commercialization.

A Study on the Effect of Particle Size on Li-Ion Battery Recycling via Flotation and Perspectives on Selective Flocculation

The recycling of active materials from Li-ion batteries (LIBs) via froth flotation has gained interest recently. To date, recycled graphite has not been pure enough for direct reuse in LIB manufacturing. The present work studied the effect of particle sizes on the grade of recycled graphite. Furthermore, selective flocculation is proposed as a novel approach to control particle sizes and thus improve graphite grade by preventing the entrainment of cathode components. Zeta potential and particle size measurements were performed to find an optimal pH for electrically selective flocculation and to study the interaction of flocculants, respectively. Batch flotation experiments were performed to investigate the effect of particle size on the purity of the recovered graphite. Results suggested that, in the absence of ultrafine fine particles, battery-grade graphite of 99.4% purity could be recovered. In the presence of ultrafine particles, a grade of 98.2% was observed. Flocculating the ultrafine feed increased the grade to 98.4%, although a drop in recovery was observed. By applying a dispersant in addition to a flocculant, the recovery could be increased while maintaining a 98.4% grade. Branched flocculants provided improved selectivity over linear flocculants. The results suggest that particle size needs to be controlled for battery-grade graphite to be recovered.

A novel mechanical pre-treatment process-chain for the recycling of Li-Ion batteries

Li-Ion batteries are strategic components widely adopted in the e-mobility, electronics and building sectors. Although recycling of Li-Ion batteries has recently received increasing attention, the closed-loop recycling, aiming at supplying high quality materials to the battery manufacturing industry, remains a challenge, due to the inherent complexity in meeting target material specifications. This paper proposes a novel Li-Ion battery mechanical pre-treatment for improved selectivity and pre-concentration of the output streams. Machining processes are employed for battery cell case cutting and size-reduction and separation stages are applied on the isolated active winding. The developed process-chain is validated and benchmarked by experimental analysis.

Overlooked Residue of Li-Ion Battery Recycling Waste as High-Value Bifunctional Oxygen Electrocatalyst for Zn-Air Batteries

Overlooked Residue of Li-Ion Battery Recycling Waste as High-Value Bifunctional Oxygen Electrocatalyst for Zn-Air Batteries

Carbothermic reduction of LiCoO2 cathode material: Thermodynamic analysis, microstructure and mechanisms

Carbothermic reduction using secondary carbon materials such as graphite anode provides an option for recycling critical elements in the spent Li-ion batteries. In this study, carbothermic reduction of battery cathode material LiCoO2 using graphite as reductant was systematically investigated. The study included thermodynamic evaluation using the FactSage™ thermochemical modelling, isothermal high-temperature experimentation at 700–1100 °C under argon atmosphere, and detailed microstructure evolution analysis to establish the mechanisms of the reduction. The products from the reduction experiments were found to be Li2CO3, Li2O, and Co, and these corresponded well with the thermodynamic assessments. The overall reduction mechanism was evaluated to start with LiCoO2 decomposition followed by the reduction of cobalt oxide to form metallic cobalt. The results also suggest that reduction occurs indirectly through reduction by CO(g). The information generated in the study are useful for improvement and parameter optimization for high temperature recycling of Li-ion batteries.

Corrosion study of 430 stainless steel with cobalt electrodeposited obtained from the recycling of Li-ion batteries

Abstract In this paper an interesting alternative for recycling of Li-ion battery cathode and and improving the corrosion resistance of 430 stainless steel is presented. The spent cathode composition has molecular formula approximately LiCoO2. The cobalt electrodeposition onto 430 SS was performed using the cobalt bath obtained by spent LiCoO2 lixiviation. In air atmosphere and high temperatures the metallic cobalt is transformed into a Co3O4 layer that acts as protection against chromium volatilization. This was confirmed by energy-dispersive X-ray spectroscopy and scanning eletron microscopy measurements. Electrochemical impedance spectroscopy measurements, in 0.5 M H2SO4 after thermal treatment at 600, 700 and 800 °C show that the cobalt electrodeposition is efficient in mitigating the effects of corrosion when 430 stainless steel is subjected to high temperatures.

Material recovery in Li-ion battery recycling: Case study

As the global demand for Lithium-ion batteries is on the rise and is expected to grow multifold in the next decade, the limited source and reserves of the raw materials like Lithium, Cobalt, Nickel, Manganese, etc. are also well known. These elements are crucial for the high energy density of batteries and are continuously in demand in the global supply chain of raw materials for battery. Hence, to optimize the utilization of these elements, battery recycling can contribute considerably. In this work, a model is developed to estimate the recovery of raw materials after recycling the battery pack of an electric bus. The cells in this battery pack had NMC (Nickel Manganese Cobalt) chemistry and the rated energy of pack was 89kWh. The elements Li, Ni, Mn and Co constitute the cathode of an NMC cell. The mass of each element in the cathode of cell is calculated and then the total mass of each element in the battery pack is estimated. Then the possible recovery of these raw materials from recycling is estimated using European Unions estimated targets of recycling. The cost of recovered material and the cost of recycling process is also calculated to estimate the efficiency of recycling. The results give an idea of the recycling efficiency and the value that can be recovered from the battery by recycling.