Economic and environmental characterization of an evolving Li-ion battery waste stream

Hybrid Microwave/Solar Energy Harvesting System Using 3D-Printed Metasurfaces

In this study, a hybrid energy harvesting system based on a conventional solar cell combined with 3D-printed metasurface units is studied. Millimeter-scale metasurface units were fabricated via the stereolithography technique, and then they were covered with conductive silver paint, in order to achieve high electric conductivity. The performance of single, as well as two-unit metasurface harvesters, was thoroughly investigated. It was found that both of them produced voltage, which peaks at their resonance frequency, demonstrating efficient energy harvesting behavior in the microwave regime. Then, the metasurface units were connected with a commercially available photovoltaic panel and the performance of the hybrid system was examined under different environmental conditions, modifying the light intensity (i.e., light, dark and shadow). It was shown that the proposed hybrid harvesting system produces a sizable voltage output, which persists, even in the case when one of the components does not contribute. Furthermore, the performance of the hybrid harvester is found to be adequate enough, although optimization of the harvesting circuit is required in order to achieve high efficiency levels. All in all, the presented experimental evidence clearly indicates the realization of a rather promising hybrid energy harvesting system, exploiting two distinct ambient energy sources, namely light and microwaves.

Selective biosorption of Li+ in aqueous solution by lithium ion-imprinted material on the surface of chitosan/attapulgite

The extraction of Li+ from liquid lithium resources is a pivotal focus of current research endeavors. Attapulgite (ATP), characterized by its distinctive layered structure and inherent ion exchange properties, emerges as an exceptional material for fabricating lithium-ion sieve. Ion-imprinted chitosan/ATP composite materials are successfully synthesized, demonstrating efficacy in selectively absorbing Li+. The results emphasize the rich functional groups present in H-CTP-2, enhancing its absorbability and selectivity, with an adsorption capacity of 37.56 mg•g-1. The adsorption conforms to the Langmuir and pseudo-second-order kinetic model. Li+ coordination involves amino and hydroxyl group, indicating a chemisorption process. Furthermore, the substantial pore structure and significant specific surface area of ATP significantly promote Li+ adsorption, suggesting its participation not only in chemisorption but also in physical adsorption. The fabricated ion-imprinted materials boast substantial adsorption capacity, exceptional selectivity, and rapid kinetics, highlighting their potential for effectively separating Li+ from aqueous solution.

Facile Gram-Scale Synthesis of Co3O4 Nanocrystal from Spent Lithium Ion Batteries and Its Electrocatalytic Application toward Oxygen Evolution Reaction

In this study, we demonstrate a new approach to easily prepare spinel Co₃O₄ nanoparticles (s-Co₃O₄ NPs) in the gram-scale from the cathode of spent lithium ion batteries (SLIBs) by the alkali leaching of hexaamminecobalt(III) complex ions. As-obtained intermediate and final products were characterized with powder X-ray diffraction (PXRD), Ultraviolet-Visible (UV-Vis), Fourier transform infrared (FTIR), and Transmission electron microscopy (TEM). Additionally, the synthesized s-Co₃O₄ NPs showed better electrocatalytic properties toward the oxygen evolution reaction (OER) in comparison to previously reported Co₃O₄ NPs and nanowires, which could be due to the more exposed electrocatalytic active sites on the s-Co₃O₄ NPs. Moreover, the electrocatalytic activity of the s-Co₃O₄ NPs was comparable to the previously reported RuO₂ catalysts. By taking advantage of the proposed recycling route, we would expect that various valuable transition metal oxide NPs could be prepared from SLIBs.

Sustainable Circular Economy for the Integration of Disadvantaged People: A Preliminary Study on the Reuse of Lithium-Ion Batteries

The circular economy is attracting the attention of governments and companies who recognize the importance of promoting a sustainable approach toward social and industrial development. The European Union requires EU State members to support a sustainable approach to improving the production and consumption of Waste Electrical and Electronic Equipment (WEEE). This paper supports the conceptualization of a sustainable circular economy model, proposing the reuse of lithium-ion batteries from WEEE. The aim is to define a circular economy-based production model for the reuse of waste lithium-ion batteries and support the inclusion of disadvantaged people in the recovery process, breaking the barriers of social discrimination. The activities introduced in this paper are part of a circular economy project for the social integration of disadvantaged people. In this paper, the preliminary results of the project are introduced, proposing a methodology for the disassembly of waste lithium-ion batteries. The disassembly line balancing proposed in this paper focuses on the need to include workers with physical, psychological, sensory, or intellectual limitations, as well as people experiencing communication difficulties. Future steps of the project will focus on the design of the assembly line to produce battery packs for pedal-assisted bicycles from the recovered lithium-ion cells.

Review on Zigzag Air Classifier

The zigzag (ZZ) classifier is a sorting and classification device with a wide range of applications (e.g., recycling, food industry). Due to the possible variation of geometry and process settings, the apparatus is used for various windows of operation due to the specifications of the separation (e.g., cut sizes from 100 µm to several decimetres, compact and fluffy materials as well as foils). Since the ZZ classifier gains more and more interest in recycling applications, it is discussed in this paper, with regards to its design, mode of operation, influencing parameters and the research to date. Research on the ZZ-classifier has been ongoing on for more than 50 years and can be divided into mainly experimental studies and modelling approaches.

Systematic Review of Lithium-Ion Battery Recycling Literature Using ProKnow-C and Methodi Ordinatio

Recycling lithium-ion batteries (LIBs) plays an important role in environmental preservation since it prevents heavy metals from polluting the soil and underground water through the recovering of valuable metals. The interest in LIB recycling has grown in recent years due to the environmental and economic gains which can be seen by increasing number of articles and publications. This review uses two methodologies: ProKnow-C and Methodi Ordinatio to create a bibliographic portfolio (BP) that defines the state-of-the-start literature in LIB recycling. This review is vital because it proposes a database of a finite number of publications of relevant authors and articles to service new research on the LIB recycling theme. The research started off with 2515 articles related to the search query which were later filtered and treated to be systematically analyzed. After filtering, 591 articles were left in the filtered raw article database (FRA-database). The efficiency and parameters of ProKnow-C and Methodi Ordinatio were counter-compared forming two databases. These databases were analyzed systematically and it was found that in the initial stages there were no differences between them. Nevertheless, in the final phases, a difference in the ranking was established when compiling the final BP of the 23 best ranked articles and authors. By using ProKnow-C and Methodi Ordinatio, this review sets out to establish a concise BP of paramount importance to the LIB recycling theme.

Separation and Efficient Recovery of Lithium from Spent Lithium-Ion Batteries

The consumption of lithium has increased dramatically in recent years. This can be primarily attributed to its use in lithium-ion batteries for the operation of hybrid and electric vehicles. Due to its specific properties, lithium will also continue to be an indispensable key component for rechargeable batteries in the next decades. An average lithium-ion battery contains 5–7% of lithium. These values indicate that used rechargeable batteries are a high-quality raw material for lithium recovery. Currently, the feasibility and reasonability of the hydrometallurgical recycling of lithium from spent lithium-ion batteries is still a field of research. This work is intended to compare the classic method of the precipitation of lithium from synthetic and real pregnant leaching liquors gained from spent lithium-ion batteries with sodium carbonate (state of the art) with alternative precipitation agents such as sodium phosphate and potassium phosphate. Furthermore, the correlation of the obtained product to the used type of phosphate is comprised. In addition, the influence of the process temperature (room temperature to boiling point), as well as the stoichiometric factor of the precipitant, is investigated in order to finally enable a statement about an efficient process, its parameter and the main dependencies.

Conceptualizing a new circular economy feature – storing renewable electricity in batteries beyond EV end-of-life: the case of Slovenia

Purpose

This paper aims to forecast the availability of used but operational electric vehicle (EV) batteries to integrate them into a circular economy concept of EVs' end-of-life (EOL) phase. Since EVs currently on the roads will become obsolete after 2030, this study focuses on the 2030–2040 period and links future renewable electricity production with the potential for storing it into used EVs' batteries. Even though battery capacity decreases by 80% or less, these batteries will remain operational and can still be seen as a valuable solution for storing peaks of renewable energy production beyond EV EOL.

Design/methodology/approach

Storing renewable electricity is gaining as much attention as increasing its production and share. However, storing it in new batteries can be expensive as well as material and energy-intensive; therefore, existing capacities should be considered. The use of battery electric vehicles (BEVs) is among the most exciting concepts on how to achieve it. Since reduced battery capacity decreases car manufacturers' interest in battery reuse and recycling is environmentally hazardous, these batteries should be integrated into the future electricity storage system. Extending the life cycle of batteries from EVs beyond the EV's life cycle is identified as a potential solution for both BEVEOL and electricity storage.

Findings

Results revealed a rise of photovoltaic (PV) solar power plants and an increasing number of EVs EOL that will have to be considered. It was forecasted that 6.27–7.22% of electricity from PV systems in scenario A (if EV lifetime is predicted to be 20 years) and 18.82–21.68% of electricity from PV systems in scenario B (if EV lifetime is predicted to be 20 years) could be stored in batteries. Storing electricity in EV batteries beyond EV EOL would significantly decrease the need for raw materials, increase energy system and EV sustainability performance simultaneously and enable leaner and more efficient electricity production and distribution network.

Practical implications

Storing electricity in used batteries would significantly decrease the need for primary materials as well as optimizing lean and efficient electricity production network.

Originality/value

Energy storage is one of the priorities of energy companies but can be expensive as well as material and energy-intensive. The use of BEV is among the most interesting concepts on how to achieve it, but they are considered only when in the use phase as vehicle to grid (V2G) concept. Because reduced battery capacity decreases the interest of car manufacturers to reuse batteries and recycling is environmentally risky, these batteries should be used for storing, especially renewable electricity peaks. Extending the life cycle of batteries beyond the EV's life cycle is identified as a potential solution for both BEV EOL and energy system sustainability, enabling more efficient energy management performance. The idea itself along with forecasting its potential is the main novelty of this paper.

Emerging Pyroelectric Nanogenerators to Convert Thermal Energy into Electrical Energy

Pyroelectric energy harvesting systems have recently received substantial attention for their potential applications as power generators. In particular, the pyroelectric effect, which converts thermal energy into electrical energy, has been utilized as an infrared (IR) sensor, but upcoming sensor technology that requires a miniscule amount of power is able to utilize pyroelectric nanogenerators (PyNGs) as a power source. Herein, an overview of the progress in the development of PyNGs for an energy harvesting system that uses environmental or artificial energies such as the sun, body heat, and heaters, is provided. It begins with a brief introduction of the pyroelectric effect, and various polymer and ceramic materials based PyNGs are reviewed in detail. Various approaches for developing polymer-based PyNGs and various ceramic materials-based PyNGs are summarized in particular. Finally, challenges and perspectives regarding the PyNGs are described.

The Effect of Using a Metal Tube on Laser Welding of the Battery Case and the Tab for Lithium-Ion Battery

Given the drawbacks of the conventional welding methods in joining the battery case and tab in the lithium-ion battery, the laser welding technique using the metal tube has been introduced for the weld. The metal tube is supposed to contribute a positive effect including protection to the outside structure by blocking the injection of the spatters, and minimization of the contact gap between the battery case and table. However, the use of the metal tube is believed to cause the plume trapped inside and affect the intensity distribution of the laser gaussian beam. Through the observation and analysis in this study, both advantages and disadvantages of the application of the metal tube on the weld have been analyzed. The use of the metal tube prevents the ejection of the spatter to the outside of the welding zone, as well as minimize the air gap between the battery case and tab in the lap joint weld is also minimized. On the other hand, the trapped plume inside the metal tube and the reduction of the energy of the laser beam have been considered to cause significant changes in the morphology, mechanical, and electrical properties of the weld.

Recycling Chain for Spent Lithium-Ion Batteries

The recycling of spent lithium-ion batteries (LIB) is becoming increasingly important with regard to environmental, economic, geostrategic, and health aspects due to the increasing amount of LIB produced, introduced into the market, and being spent in the following years. The recycling itself becomes a challenge to face on one hand the special aspects of LIB-technology and on the other hand to reply to the idea of circular economy. In this paper, we analyze the different recycling concepts for spent LIBs and categorize them according to state-of-the-art schemes of waste treatment technology. Therefore, we structure the different processes into process stages and unit processes. Several recycling technologies are treating spent lithium-ion batteries worldwide focusing on one or several process stages or unit processes.

Microwave-absorbing properties of cathode material during reduction roasting for spent lithium-ion battery recycling

As a hazardous material to the environment and human health, spent lithium-ion batteries need to be recycled in a reasonable way. To explore the effect of microwave heating on spent lithium-ion batteries (LIBs) recycling, the microwave-absorbing properties of a spent cathode powder (LiNi_xCo_yMn_zO₂) were studied by measuring its dielectric properties from 25-900 °C at 2450 MHz under different conditions (temperature, carbon dose and apparent density). X-ray diffraction and thermogravimetric analysis (TGA) were used to study decomposition and reduction reactions in the heating process. The results indicated that the cathode material has good microwave-absorbing properties over the entire temperature range (25-900 °C), especially when mixed with carbon. As the reduction reactions proceed, the dielectric properties of the material increase rapidly from 600 °C, which means that microwave heating can promote a carbothermal reduction reaction. The effect of the carbon dose on the dielectric properties indicates that the carbothermal reduction reaction can fully occur when the carbon dose reaches 18%. Furthermore, the best microwave-absorbing performance can be achieved when the apparent density of the material is 1.41 g/cm³. These studies have established a basis for research towards the direct recovery of lithium from LIBs by microwave reduction roasting.

Reduction-ammoniacal leaching to recycle lithium, cobalt, and nickel from spent lithium-ion batteries with a hydrothermal method: Effect of reductants and ammonium salts

Some inevitable issues of the acid leaching method used to recycle spent lithium-ion batteries (LIBs), such as toxic gas emission, excessive acid-base consumption, inferior metal selectivity and equipment corrosion, have gradually emerged and restricted the promotion and development of this method. It is therefore essential to develop a sustainable closed-loop recycling technology (reduction-ammoniacal method) for spent LIBs. In this study, the effects of various species of ammonia, ammonium salts and reductants on the leaching of Li, Co, Ni, Mn and Al from spent LIBs were investigated with a hydrothermal method. An increase of the electrode potential of the reductant greatly accelerated the selective leaching of Li, Co and Ni, which agreed with the thermodynamic analysis results. The standard electrode potentials of the LiNi_xCo_yMn_1-x-yO₂ (NCM) materials were also determined by using approximate calculations. When using (NH₄)₂SO₃ as a reductant in a one-step leaching process, 100% Co, 98.3% Ni and 90.3% Li were extracted into the ammonia-ammonium chloride solutions. From the kinetics analysis, the surface chemical reaction shrinking core model was found to control the leaching behavior of Li, Co, and Ni in the reduction-ammoniacal leaching process. A shell-core structure was composed of a product layer, a diffusion layer of the solid core and an unreacted core. Species in the product layer reduced the leaching efficiencies of Li, Co, and Ni. The results obtained for this hydrothermal reduction-ammoniacal method applied to recycle spent LIBs provide insights for the design of a high-speed, exceptionally selective, closed-loop recycling technique.

A Structured Literature Review on Obsolete Electric Vehicles Management Practices

The use of electricity for transportation needs offers the chance to replace fossil fuels with greener energy sources. Potentially, coupling sustainable transports with Renewable Energies (RE) could reduce significantly both Greenhouse Gas (GHG) emissions and the dependency on oil imports. However, the expected growth rate of Electric Vehicles (EVs) could become also a potential risk for the environment if recycling processes will continue to function in the current way. To this aim, the paper reviews the international literature on obsolete EV management practices, by considering scientific works published from 2000 up to 2019. Results show that the experts have paid great attention to this topic, given both the critical and valuable materials embedded in EVs and their main components (especially traction batteries), by offering interesting potential profits, and identifying the most promising End-of-Life (EoL) strategy for recycling both in technological and environmental terms. However, the economics of EV recycling systems have not yet been well quantified. The intent of this work is to enhance the current literature gaps and to propose future research streams.

Hybrid Energy Harvesters: Toward Sustainable Energy Harvesting

Recently, sustainable green energy harvesting systems have been receiving great attention for their potential use in self-powered smart wireless sensor network (WSN) systems. In particular, though the developed WSN systems are able to advance public good, very high and long-term budgets will be required in order to use them to supply electrical energy through temporary batteries or connecting power cables. This report summarizes recent significant progress in the development of hybrid nanogenerators for a sustainable energy harvesting system that use natural and artificial energies such as solar, wind, wave, heat, machine vibration, and automobile noise. It starts with a brief introduction of energy harvesting systems, and then summarizes the different hybrid energy harvesting systems: integration of mechanical and photovoltaic energy harvesters, integration of mechanical and thermal energy harvesters, integration of thermal and photovoltaic energy harvesters, and others. In terms of the reported hybrid nanogenerators, a systematic summary of their structures, working mechanisms, and output performances is provided. Specifically, electromagnetic induction, triboelectric, piezoelectric, photovoltaic, thermoelectric, and pyroelectric effects are reviewed on the basis of the individual and hybrid power performances of hybrid nanogenerators and their practical applications with various device designs. Finally, the perspectives on and challenges in developing high performance and sustainable hybrid nanogenerator systems are presented.

Recycling of Lithium Iron Phosphate Batteries: Future Prospects and Research Needs

Since the first synthesis of lithium iron phosphate (LFP) as active cathode material for lithium-ion batteries (LIB) in 1996, it has gained a considerable market share and further growth is expected. Main applications are the fast-growing sectors electromobility and to a lesser extend stationary energy storage. Despite increasing return flows, so far, little emphasis has been put on the recycling of LFP batteries due to the low content of high-value metals. In this study, current developments in the LFP battery market are presented. Furthermore, recycling processes for LIBs are reviewed and their applicability for LFP batteries is assessed. Currently, China is the main market for LFP batteries and rapidly increasing return flows are observed. In Europe and the USA, other battery chemistries are predominant. For LFP battery recycling, individually adaptable processes based on mechanical treatment of the cells followed by hydrometallurgical processing of the active cathode material seem to be the most promising approach. However, at present, these processes are only available at pilot scale, the profitability and their environmental performance are questionable. Therefore, further research addressing these challenges is urgently needed.

Lithiation-Aided Conversion of End-of-Life Lithium-Ion Battery Anodes to High-Quality Graphene and Graphene Oxide

In the past two decades, lithium-ion (Li-ion) batteries have transformed the appearance of the world. Along with the ever-increasing production and usage are the tremendous number of retired batteries, which have created social and environmental issues, making battery recycling an urgent task. Graphene has exhibited outstanding electronic and mechanical properties but it is still difficult to fabricate high-quality graphene with feasible procedures at low cost. Here, a strategy of smartly converting retired Li-ion battery anodes to graphene and graphene oxide is proposed. The graphite powders collected from end-of-life Li-ion batteries exhibited irregular expansion because of the lithium-ion intercalation and deintercalation in the anodegraphite during battery charge/discharge. Such prefabrication process facilitated both chemical and physical exfoliations of the graphite. Comparing with the graphene oxide derived from pristine, untreated graphite, the graphene oxide from anodegraphite exhibited superlative homogeneity and electrochemical properties. The lithiation aided pre-expansion enabled 4 times enhancement of graphene productivity by shear mixing. Furthermore, the graphene fabrication was seamlessly inserted into the currently used battery recycling streamline in which the acid treatment was found to further swell the graphite lattice, pushing up the graphene productivity to 83.7% (10 times higher than that of pristine graphite powders). The findings create new opportunities for capitalizing on waste batteries to produce high-quality graphene and its derivatives.

Recovery of valuable metals from mixed types of spent lithium ion batteries. Part II: Selective extraction of lithium

Extensive usage of different kinds of lithium ion batteries (LIBs) may result in a huge amount of complicated waste batteries stream, while insufficient attention has been paid on the selective recovery of lithium from these already complicated wastes. Herein, a novel approach was developed for the selective extraction of Li from mixed types of LIBs (LiCoO₂, LiMn₂O₄, LiFePO₄ and LiCo_1/3Mn_1/3Ni_1/3O₂) using mild phosphoric acid as efficient leaching agent. It can be concluded from leaching results that 100%, 92.86%, 97.57% and 98.94% Li can be selectively extracted from waste cathode materials of LiCoO₂, LiMn₂O₄, LiFePO₄ and LiCo_1/3Mn_1/3Ni_1/3O₂, respectively, while transition metals (Co, Mn, Fe and Ni) can be hardly leached in mild acidic media under optimized leaching conditions. In addition, high selectivity coefficients (β_Li/Me) can be obtained during the extraction of Li from other metals. It can be also discovered from characterization results (SEM, XRD, FT-IR and Raman spectra) that leaching residues are phosphate precipitates, which might be used for the recycling of other metals and preparation of cathode materials. Results from leaching kinetics indicate that the leaching of Li is chemical and internal diffusion controlled reaction, with apparent activation energy (Ea) of 37.74, 21.16, 27.47 and 21.86 kJ/mol for LiCoO₂, LiMn₂O₄, LiFePO₄ and LiCo_1/3Mn_1/3Ni_1/3O₂, respectively. Finally, lithium phosphate with a purity of 98.4% can be obtained and the whole process can be efficient candidate for Li recovery with minor environmental impact and little waste produced.

Impact of Phosphate Adsorption on Complex Cobalt Oxide Nanoparticle Dispersibility in Aqueous Media

A commonly overlooked and largely unknown aspect of assessing the environmental and biological safety of engineered nanomaterials is their transformation in aqueous systems. Complex metal oxides are an important class of materials for catalysis, energy storage, and water purification. However, the potential impact of nano complex metal oxides on the environment upon improper disposal is not well understood. We present a comprehensive analysis of the interaction of an environmentally relevant oxyanion, phosphate, with a complex metal oxide nanomaterial, lithium cobalt oxide. Our results show that adsorption of phosphate to the surface of these materials drastically impacts their surface charge, rendering them more stable in aqueous systems. The adsorbed phosphate remains on the surface over significant periods of time, suggesting that desorption is not kinetically favored. The implications of this interaction may be increased dispersibility and bioavailability of these materials in environmental water systems.

Leaching Behavior Analysis of Valuable Metals from Lithium-Ion Batteries Cathode Material

The paper concerns an approach about using environmental technology and hydrometallurgical process to the recovery of valuable metal from waste cathode material produced during the manufacture of lithium-ion batteries. It is noteworthy that the content of nickel, manganese and cobalt from cathode material are in the extraordinary large proportion. In the acid leaching step, the essential effects of H2SO4 concentration, H2O2 concentration, leaching time, liquid-solid mass ratio and reaction temperature with the leaching percentage were investigated. The cathode material was leached with 2M H2SO4 and 10 vol.% H2O2 at 70 °C and 300 rpm using a liquid-solid mass ratio of 30 ml/g and the leaching efficiency of cobalt was 98.5%, lithium was 99.8%, nickel was 98.6% and manganese was 98.6% under optimum conditions. Kinetic study demonstrates the activation energies for those analyzed metals with Arrhenius equation and manifests the data with hybrid reaction control mechanism. The process was proved from activation energies ranged from 27.79 to 47.25 kJ/mol. Finally, the valuable metals will be leached in sulfuric acid effectively.

Sustainable recovery of valuable metals from spent lithium-ion batteries using DL-malic acid: Leaching and kinetics aspect

An eco-friendly and benign process has been investigated for the dissolution of Li, Co, Ni, and Mn from the cathode materials of spent LiNi_1/3Co_1/3Mn_1/3O₂ batteries, using DL-malic acid as the leaching agent in this study. The leaching efficiencies of Li, Co, Ni, and Mn can reach about 98.9%, 94.3%, 95.1%, and 96.4%, respectively, under the leaching conditions of DL-malic acid concentration of 1.2 M, hydrogen peroxide content of 1.5 vol.%, solid-to-liquid ratio of 40 g l^-1, leaching temperature of 80°C, and leaching time of 30 min. In addition, the leaching kinetic was investigated based on the shrinking model and the results reveal that the leaching reaction is controlled by chemical reactions within 10 min with activation energies (Ea) of 21.3 kJ·mol^-1, 30.4 kJ·mol^-1, 27.9 kJ·mol^-1, and 26.2 kJ·mol^-1 for Li, Co, Ni, and Mn, respectively. Diffusion process becomes the controlled step with a prolonged leaching time from 15 to 30 min, and the activation energies (Ea) are 20.2 kJ·mol^-1, 28.9 kJ·mol^-1, 26.3 kJ·mol^-1, and 25.0 kJ·mol^-1 for Li, Co, Ni, and Mn, respectively. This hydrometallurgical route was found to be effective and environmentally friendly for leaching metals from spent lithium batteries.

Recovery of valuable metals from waste cathode materials of spent lithium-ion batteries using mild phosphoric acid

Sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) may be necessary to alleviate the depletion of strategic metal resources and potential risk of environmental pollution. Herein a hydrometallurgical process was proposed to explore the possibility for the recovery of valuable metals from the cathode materials (LiCoO₂) of spent LIBs using phosphoric acid as both leaching and precipitating agent under mild leaching conditions. According to the leaching results, over 99% Co can be separated and recovered as Co₃(PO₄)₂ in a short-cut process involved merely with leaching and filtrating, under the optimized leaching conditions of 40°C (T), 60min (t), 4 vol.% H₂O₂, 20mLg^-1 (L/S) and 0.7mol/L H₃PO₄. Then leaching kinetics was investigated based on the logarithmic rate kinetics model and the obtained results indicate that the leaching of Co and Li fits well with this model and the activation energies (Ea) for Co and Li are 7.3 and 10.2kJ/mol, respectively. Finally, it can be discovered from characterization results that the obtained product is 97.1% pure cobalt phosphate (Co₃(PO4)₂).

Designing and examining e-waste recycling process: methodology and case studies

Increasing concerns on resource depletion and environmental pollution have largely obliged electrical and electronic waste (e-waste) should be tackled in an environmentally sound manner. Recycling process development is regarded as the most effective and fundamental to solve the e-waste problem. Based on global achievements related to e-waste recycling in the past 15 years, we first propose a theory to design an e-waste recycling process, including measuring e-waste recyclability and selection of recycling process. And we summarize the indicators and tools in terms of resource dimension, environmental dimension, and economic dimension, to examine the e-waste recycling process. Using the sophisticated experience and adequate information of e-waste management, spent lithium-ion batteries and waste printed circuit boards are chosen as case studies to implement and verify the proposed method. All the potential theory and obtained results in this work can contribute to future e-waste management toward best available techniques and best environmental practices.

Leaching of electrodic powders from lithium ion batteries: Optimization of operating conditions and effect of physical pretreatment for waste fraction retrieval

Experimental results of leaching tests using waste fractions obtained by mechanical pretreatment of lithium ion batteries (LIB) were reported. Two physical pretreatments were performed at pilot scale in order to recover electrodic powders: the first including crushing, milling, and sieving and the second granulation, and sieving. Recovery yield of electrodic powder was significantly influenced by the type of pretreatment. About 50% of initial LIB wastes was recovered by the first treatment (as electrodic powder with size <0.5mm, Sample 1), while only 37% of powder with size <1mm (Sample 2) can be recovered by the second treatment. Chemical digestion put in evidence the heterogeneity of recovered powders denoting different amounts of Co, Mn, and Ni. Leaching tests of both powders were performed in order to determine optimized conditions for metal extraction. Solid/liquid ratios and sulfuric acid concentrations were changed according to factorial designs at constant temperature (80°C). Optimized conditions for quantitative extraction (>99%) of Co and Li from Sample 1 are 1/10g/mL as solid/liquid ratio and +50% stoichiometric excess of acid (1.1M). Using the same solid/liquid ratio, +100% acid excess (1.2M) is necessary to extract 96% of Co and 86% of Li from Sample 2. Best conditions for leaching of Sample 2 using glucose are +200% acid excess (1.7M) and 0.05M glucose concentration. Optimized conditions found in this work are among the most effective reported in the literature in term of Co extraction and reagent consumption.

Enhanced recycling network for spent e-bicycle batteries: A case study in Xuzhou, China

Electric bicycles (e-bicycles) are a primary means of commuting in China because of their light weight, speed, and low maintenance costs. Owing to short service life and environmental pollution hazards, recycling and reuse of e-bicycle batteries has always been a focus of industry and academia. As a typical case of both production and use of large electric bicycles, 113 major sellers, 378 corporate and individual buyers, 147 large e-bicycle repair centers, and 1317 e-bicycle owners in Xuzhou City were investigated in order to understand the sales, use, recycling, and disposal of spent e-bicycle batteries. The findings show that the existing distempered recycling system is the main limitation of spent battery recovery, and the actual recovery rate of spent batteries is lower than the estimated output (QW) for the years 2011-2014. Electric bicycle sellers play a fundamental role in the collection of spent batteries in Xuzhou, accounting for 42.3±8.3% of all batteries recovered. The widespread use of lithium batteries in recent years has resulted in a reduction in spent battery recycling because of lower battery prices. Furthermore, consumer preferences are another important factor affecting the actual recovery rate according to survey results evaluated using canonical correspondence analysis. In this paper, we suggest that a reverse logistics network system for spent battery recycling should be established in the future; in addition, enhancing producer responsibility, increasing publicity, raising of public awareness, developing green public transport, and reducing dependence on e-bicycles also should be pursued. This study seeks to provide guidance for planning construction and management policies for an effective spent battery recycling system in China and other developing countries.

Leaching lithium from the anode electrode materials of spent lithium-ion batteries by hydrochloric acid (HCl)

Spent lithium-ion batteries (LIBs) are considered as an important secondary resource for its high contents of valuable components, such as lithium and cobalt. Currently, studies mainly focus on the recycling of cathode electrodes. There are few studies concentrating on the recovery of anode electrodes. In this work, based on the analysis result of high amount of lithium contained in the anode electrode, the acid leaching process was applied to recycle lithium from anode electrodes of spent LIBs. Hydrochloric acid was introduced as leaching reagent, and hydrogen peroxide as reducing agent. Within the range of experiment performed, hydrogen peroxide was found to have little effect on lithium leaching process. The highest leaching recovery of 99.4wt% Li was obtained at leaching temperature of 80°C, 3M hydrochloric acid and S/L ratio of 1:50g/ml for 90min. The graphite configuration with a better crystal structure obtained after the leaching process can also be recycled.

Cobalt products from real waste fractions of end of life lithium ion batteries

An innovative process was optimized to recover Co from portable Lithium Ion Batteries (LIB). Pilot scale physical pretreatment was performed to recover electrodic powder from LIB. Co was extracted from electrodic powder by a hydrometallurgical process including the following main stages: leaching (by acid reducing conditions), primary purification (by precipitation of metal impurities), solvent extraction with D2EPHA (for removal of metal impurities), solvent extraction with Cyanex 272 (for separation of cobalt from nickel), cobalt recovery (by precipitation of cobalt carbonate). Tests were separately performed to identify the optimal operating conditions for precipitation (pH 3.8 or 4.8), solvent extraction with D2EHPA (pH 3.8; Mn/D2EHPA=4; 10% TBP; two sequential extractive steps) and solvent extraction with Cyanex 272 (pH 3.8; Cyanex/Cobalt=4, 10% TBP, one extractive step). The sequence of optimized process stages was finally performed to obtain cobalt carbonate. Products with different degree of purity were obtained depending on the performed purification steps (precipitation with or without solvent extraction). 95% purity was achieved by implementation of the process including the solvent extraction stages with D2EHPA and Cyanex 272 and final washing for sodium removal.

Targeting high value metals in lithium-ion battery recycling via shredding and size-based separation

Development of lithium-ion battery recycling systems is a current focus of much research; however, significant research remains to optimize the process. One key area not studied is the utilization of mechanical pre-recycling steps to improve overall yield. This work proposes a pre-recycling process, including mechanical shredding and size-based sorting steps, with the goal of potential future scale-up to the industrial level. This pre-recycling process aims to achieve material segregation with a focus on the metallic portion and provide clear targets for subsequent recycling processes. The results show that contained metallic materials can be segregated into different size fractions at different levels. For example, for lithium cobalt oxide batteries, cobalt content has been improved from 35% by weight in the metallic portion before this pre-recycling process to 82% in the ultrafine (<0.5mm) fraction and to 68% in the fine (0.5-1mm) fraction, and been excluded in the larger pieces (>6mm). However, size fractions across multiple battery chemistries showed significant variability in material concentration. This finding indicates that sorting by cathode before pre-treatment could reduce the uncertainty of input materials and therefore improve the purity of output streams. Thus, battery labeling systems may be an important step towards implementation of any pre-recycling process.

Twelve Principles for Green Energy Storage in Grid Applications

The introduction of energy storage technologies to the grid could enable greater integration of renewables, improve system resilience and reliability, and offer cost effective alternatives to transmission and distribution upgrades. The integration of energy storage systems into the electrical grid can lead to different environmental outcomes based on the grid application, the existing generation mix, and the demand. Given this complexity, a framework is needed to systematically inform design and technology selection about the environmental impacts that emerge when considering energy storage options to improve sustainability performance of the grid. To achieve this, 12 fundamental principles specific to the design and grid application of energy storage systems are developed to inform policy makers, designers, and operators. The principles are grouped into three categories: (1) system integration for grid applications, (2) the maintenance and operation of energy storage, and (3) the design of energy storage systems. We illustrate the application of each principle through examples published in the academic literature, illustrative calculations, and a case study with an off-grid application of vanadium redox flow batteries (VRFBs). In addition, trade-offs that can emerge between principles are highlighted.