Pyrometallurgical recycling of end-of-life lithium-ion batteries

The global importance of lithium-ion batteries(LIBs)has been increasingly underscored with the advancement of high-performance energy storage technologies.However,the end-of-life of these batteries poses significant challenges from environmental,economic,and resource management perspectives.This review paper focuses on the pyrometallurgy-based recycling process of lithium-ion batteries,exploring the fundamental understanding of this process and the importance of its optimization.Centering on the high energy consumption and emission gas issues of the pyrometallurgical recycling process,we systematically analyzed the capital-intensive nature of this process and the resulting technological characteristics.Furthermore,we conducted an in-depth discussion on the future research directions to overcome the existing technological barriers and limitations.This review will provide valuable insights for researchers and industry stakeholders in the battery recycling field.

Comparison of isotope-based linear and Bayesian mixing models in determining moisture recycling ratio

Stable water isotopes are natural tracers quantifying the contribution of moisture recycling to local precipitation,i.e.,the moisture recycling ratio,but various isotope-based models usually lead to different results,which affects the accuracy of local moisture recycling.In this study,a total of 18 stations from four typical areas in China were selected to compare the performance of isotope-based linear and Bayesian mixing models and to determine local moisture recycling ratio.Among the three vapor sources including advection,transpiration,and surface evaporation,the advection vapor usually played a dominant role,and the contribution of surface evaporation was less than that of transpiration.When the abnormal values were ignored,the arithmetic averages of differences between isotope-based linear and the Bayesian mixing models were 0.9%for transpiration,0.2%for surface evaporation,and–1.1%for advection,respectively,and the medians were 0.5%,0.2%,and–0.8%,respectively.The importance of transpiration was slightly less for most cases when the Bayesian mixing model was applied,and the contribution of advection was relatively larger.The Bayesian mixing model was found to perform better in determining an efficient solution since linear model sometimes resulted in negative contribution ratios.Sensitivity test with two isotope scenarios indicated that the Bayesian model had a relatively low sensitivity to the changes in isotope input,and it was important to accurately estimate the isotopes in precipitation vapor.Generally,the Bayesian mixing model should be recommended instead of a linear model.The findings are useful for understanding the performance of isotope-based linear and Bayesian mixing models under various climate backgrounds.

Development of sustainable and efficient recycling technology for spent Li-ion batteries: Traditional and transformation go hand in hand

Clean and efficient recycling of spent lithium-ion batteries(LIBs)has become an urgent need to promote sustainable and rapid development of human society.Therefore,we provide a critical and comprehensive overview of the various technologies for recycling spent LIBs,starting with lithium-ion power batteries.Recent research on raw material collection,metallurgical recovery,separation and purification is highlighted,particularly in terms of all aspects of economic efficiency,energy consumption,technology transformation and policy management.Mechanisms and pathways for transformative full-component recovery of spent LIBs are explored,revealing a clean and efficient closed-loop recovery mechanism.Optimization methods are proposed for future recycling technologies,with a focus on how future research directions can be industrialized.Ultimately,based on life-cycle assessment,the challenges of future recycling are revealed from the LIBs supply chain and stability of the supply chain of the new energy battery industry to provide an outlook on clean and efficient short process recycling technologies.This work is designed to support the sustainable development of the new energy power industry,to help meet the needs of global decarbonization strategies and to respond to the major needs of industrialized recycling.

An efficient and mild recycling of waste melamine formaldehyde foams by alkaline hydrolysis

Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditions(160℃)in a NaOH–H2O system with ammelide and ammeline as the main degradation products.The alkaline solvent had an obvious corrosion effect for MFF,as indicated by scanning electron microscopy(SEM).The reaction process and products distribution were studied by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and ^(13)C nuclear magnetic resonance(NMR).Besides,the MFF degradation products that have the similar chemical structures and bonding performances to those of melamine can be directly used as the raw material for synthesis of melamine urea-formaldehyde resins(MUFs).Moreover,the degradation system demonstrated here showed the high degradation efficiency after reusing for 7 times.The degradation process generated few harmful pollutants and no pre-or post-treatments were required,which proves its feasibility in the safe removal or recovery of waste MFF.

Increasing Threat of Scarcity Prompts Rise in Water Recycling

In January 2018,construction wrapped on Salesforce Tower(Fig.1),a 61-story office building that now dominates the skyline of San Francisco,CA,USA.In addition to being the tallest building in the city,Salesforce Tower is the largest structure in the world with an onsite water recycling system.Built by the Australian com-pany Aquacell(Milton,NSW,Australia),the system cleans 113 m^(3)of sewage,sink,shower,and other wastewater each day for use in irrigation and flushing toilets,saving an estimated 35000 m?of water anmually[1].The building is just one of dozens in San Fran-cisco outitted with their own water recycling systems,thanks to a city mandate enacted in 2015[1].

Progress,challenges,and prospects of spent lithium-ion batteries recycling:A review

The recycling and reutilization of spent lithium-ion batteries(LIBs)have become an important measure to alleviate problems like resource scarcity and environmental pollution.Although some progress has been made,battery recycling technology still faces challenges in terms of efficiency,effectiveness and environmental sustainability.This review aims to systematically review and analyze the current status of spent LIB recycling,and conduct a detailed comparison and evaluation of different recycling processes.In addition,this review introduces emerging recycling techniques,including deep eutectic solvents,molten salt roasting,and direct regeneration,with the intent of enhancing recycling efficiency and diminishing environmental repercussions.Furthermore,to increase the added value of recycled materials,this review proposes the concept of upgrading recycled materials into high value-added functional materials,such as catalysts,adsorbents,and graphene.Through life cycle assessment,the paper also explores the economic and environmental impacts of current battery recycling and highlights the importance that future recycling technologies should achieve a balance between recycling efficiency,economics and environmental benefits.Finally,this review outlines the opportunities and challenges of recycling key materials for next-generation batteries,and proposes relevant policy recommendations to promote the green and sustainable development of batteries,circular economy,and ecological civilization.

Recycling of spent lithium-ion batteries as a sustainable solution to obtain raw materials for different applications

Lithium-ion batteries(LIBs)containing graphite as anode material and LiCoO_(2),LiMn_(2)O_(4),and LiNi_(x)Mn_(y)Co_(z)O_(2) as cathode materials are the most used worldwide because of their high energy density,capacitance,durability,and safety.However,such widespread use implies the generation of large amounts of electronic waste.It is estimated that more than 11 million ton of LIBs waste will have been generated by 2030.Battery recycling can contribute to minimizing environmental contamination and reducing production costs through the recovery of high-value raw materials such as lithium,cobalt,and nickel.The most common processes used to recycle spent LIBs are pyrometallurgical,biometallurgical,and hydrometallurgical.Given the current scenario,it is necessary to develop environmentally friendly methods to recycle batteries and synthesize materials with multiple technological applications.This study presents a review of industrial and laboratory processes for recycling spent LIBs and producing materials that can be used in new batteries,energy storage devices,electrochemical sensors,and photocatalytic reactions.

Pyrometallurgical recycling of spent lithium-ion batteries from conventional roasting to synergistic pyrolysis with organic wastes

The synergistic pyrolysis has been increasingly used for recycling spent lithium-ion batteries(LIBs)and organic wastes(hydrogen and carbon sources),which are in-situ transformed into various reducing agents such as H_(2),CO,and char via carbothermal and/or gas thermal reduction.Compared with the conventional roasting methods,this“killing two birds with one stone”strategy can not only reduce the cost and energy consumption,but also realize the valorization of organic wastes.This paper concluded the research progress in synergistic pyrolysis recycling of spent LIBs and organic wastes.On the one hand,valued metals such as Li,Co,Ni,and Mn can be recovered through the pyrolysis of the cathode materials with inherent organic materials(e.g.,separator,electrolyte)or graphite anode.During the pyrolysis process,the organic materials are decomposed into char and gases(e.g.,CO,H_(2),and CH_(4))as reducing agents,while the cathode material is decomposed and then converted into Li_(2)CO_(3) and low-valent transition metals or their oxides via in-situ thermal reduction.The formed Li_(2)CO_(3) can be easily recovered by the water leaching process,while the formed transition metals or their oxides(e.g.,Co,CoO,Ni,MnO,etc.)can be recovered by the reductant-free acid leaching or magnetic separation process.On the other hand,organic wastes(e.g.,biomass,plastics,etc.)as abundant hydrogen and carbon sources can be converted into gas(e.g.,H_(2),CO,etc.)and char via pyrolysis.The cathode materials are decomposed and subsequently reduced by the pyrolysis gas and char.In addition,the pyrolysis oil and gas can be upgraded by catalytic reforming with the active metals derived from cathode material.Finally,great challenges are proposed to promote this promising technology in the industrial applications.

Hydrometallurgical detoxification and recycling of electric arc furnace dust

Electric arc furnace dust(EAFD)is a hazardous waste but can also be a potential secondary resource for valuable metals,such as Zn and Fe.Given the increased awareness of carbon emission reduction,energy conservation,and environmental protection,hydrometallurgical technologies for the detoxification and resource use of EAFD have been developing rapidly.This work summarizes the generation mechanisms,compositions,and characteristics of EAFD and presents a critical review of various hydrometallurgical treatment methods for EAFD,e.g.,acid leaching,alkaline leaching,salt leaching,and pretreatment–enhanced leaching methods.Simultaneously,the phase transformation mechanisms of zinc-containing components in acid and alkali solutions and pretreatment processes are expounded.Finally,two novel combined methods,i.e.,oxygen pressure sulfuric acid leaching combined with composite catalyst preparation,and synergistic roasting of EAFD and municipal solid waste incineration fly ash combined with alkaline leaching,are proposed,which can provide future development directions to completely recycling EAFD by recovering valuable metals and using zinc residue.

A CO_(2)-controllable phase change absorbent solvent used to waste recycling of dining lampblack

Dining lampblack as a source of atmospheric pollution,urban residents had to spend a lot of economic costs all year round to solve its impact.However,traditional treatment methods often carry the risk of secondary pollution.The use of phase change absorption solvent(PCAS)controlled by CO_(2)can effectively absorb the oily components in dining lampblack,and smoothly avoid the generation of secondary pollutants and squandering of resources.The reversibility of PCASs under CO_(2)control was explained by pH changes and macroscopic visualizations.The absorption effects of favorable absorbents and PCASs on dining lampblack were compared and analyzed.The fatty acid(FA)in the oil absorption mixture was desorbed by interacting with D230.The results of GC/MS analysis on the oil components separated by desorption showed that the desorption of PCASs was effective for these refractory oil components.FAs can be enriched and applied to the subsequent dining lampblack treatment link to realize the waste recycling.In addition,the absorption and desorption of oily components by PCASs were combined with the CO_(2)-controlled phase transformation of PCASs itself to achieve the absorption circulation of treating dining lampblack by using PCASs.

Efficient heavy metal recycling and water reuse from industrial wastewater using new reusable and inexpensive polyphenylene sulfide derivatives

Heavy metal(HM)pollution is a serious environment problem.Recovering HM from industrial wastewater by efficient adsorbents is a sustainable method due to recycling HM and acquiring reusable water.However,popular efficient adsorbents are usually expensive or non-reusable.In this paper,methods of efficient HM recycling and water reuse from industrial wastewater were developed using efficient adsorbents,new polyphenylene sulfide derivatives,which are recyclable and stable in an acidic,alkaline or oxidative aqueous solution.Moreover,they can efficiently and quickly adsorb HM ions.The maximum adsorption capacities of these adsorbents for HM ions are at the range from 51.3-184.2 mg·g^(-1).The adsorption equilibrium times of them for HM ions are at the range from 10 to 80 min.Therefore,this paper suggests sustainable methods of HM recovery and water reuse from industrial wastewater.

Green recycling of short-circuited garnet-type electrolyte for high-performance solid-state lithium batteries

Solid-state lithium batteries(SSLBs)solve safety issues and are potentially energy-dense alternatives to next-generation energy storage systems.Battery green recycling routes are responsible for the widespread use of SSLBs due to minimizing environmental contamination,reducing production costs,and providing a sustainable solution for resources,e.g.,saving rare earth elements(La,Ta,etc.).Herein,a solid-state recycling strategy is proposed to achieve green recycling of the crucial component solidstate electrolytes(SSEs)in spent SSLBs.The short-circuited garnet Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)is broken into fine particles and mixed with fresh particles to improve sintering activity and achieve high packing density.The continuous Li absorption process promotes sufficient grain fusion and guarantees the transformation from tetragonal phase to pure cubic phase for high-performance recycled LLZTO.The Li-ion conductivity reaches 5.80×10^(-4)S cm-1with a relative density of 95.9%.Symmetric Li cell with asrecycled LLZTO shows long-term cycling stability for 700 h at 0.3 mA cm^(-2)without any voltage hysteresis.Full cell exhibits an excellent cycling performance with a discharge capacity of 141.5 mA h g^(-1)and a capacity retention of 92.1%after 400 cycles(0.2C).This work develops an environmentally friendly and economically controllable strategy to recycle SSE from spent SSLBs,guiding future directions of SSLBs large-scale industrial application and green recycling study.

Recycling and recovery of spent copper-indium-gallium-diselenide(CIGS)solar cells:A review

Copper-indium-gallium-diselenide(CIGS)is a fast-evolving commercial solar cell.The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling.In this paper,the sources and characteristics of valuable metals in spent CIGS solar cells were reviewed.The potential environmental impacts of CIGS,including service life,critical material,and material toxicity,were outlined.The main recovery methods of valuable metals in the various types of spent CIGS,including hydrometallurgy,pyrometallurgy,and comprehensive treatment processes,were compared and discussed.The mechanism of different recovery processes was summarized.The challenges faced by different recycling processes of spent CIGS were also covered in this review.Finally,the economic viability of the recycling process was assessed.The purpose of this review is to provide reasonable suggestions for the sustainable development of CIGS and the harmless disposal of spent CIGS.

Recycling and utilization of coal gasification residues for fabricating Fe/C composites as novel microwave absorbents

Under the background of a transformation of the global energy structure,coal gasification technology has a wide application prospect,but its by-product,the coal gasification residue(CGR),is still not being efficiently utilized for recycling.The CGR contains abundant carbon components,which could be applied to the microwave absorption field as the carbon matrix.In this study,Fe/CGR composites are fabricated via a two-step method,including the impregnation of Fe^(3+)and the reduction process.The influence of the different loading capacities of the Fe component on the morphology and electromagnetic properties is studied.Moreover,the loading content of Fe and the surface morphology of the Fe/CGR can be reasonably controlled by adjusting the concentration of the ferric nitrate solution.Meanwhile,Fe particles are evenly inserted on the CGR framework,which expands the Fe/CGR interfaces to enhance interfacial polarization,thus further improving the microwave-absorbing(MA)properties of composites.Particularly,as the Fe^(3+)concentration is 1.0 mol/L,the Fe/CGR composite exhibits outstanding performance.The reflection loss reaches-39.3 dB at 2.5 mm,and the absorption bandwidth covers 4.1 GHz at 1.5 mm.In this study,facile processability,resource recycling,appropriately matched impedance,and excellent MA performance are achieved.Finally,the Fe/CGR composites not only enhance the recycling of the CGR but also pioneer a new path for the synthesis of excellent absorbents.

Deep Consensus Network for Recycling Waste Detection in Smart Cities

Recently,urbanization becomes a major concern for developing as well as developed countries.Owing to the increased urbanization,one of the important challenging issues in smart cities is waste management.So,automated waste detection and classification model becomes necessary for the smart city and to accomplish better recyclable waste management.Effective recycling of waste offers the chance of reducing the quantity of waste disposed to the land fill by minimizing the requirement of collecting raw materials.This study develops a novel Deep Consensus Network with Whale Optimization Algorithm for Recycling Waste Object Detection(DCNWORWOD)in Smart Cities.The goal of the DCNWO-RWOD technique intends to properly identify and classify the objects into recyclable and non-recyclable ones.The proposed DCNWO-RWOD technique involves the design of deep consensus network(DCN)to detect waste objects in the input image.For improving the overall object detection performance of the DCN model,the whale optimization algorithm(WOA)is exploited.Finally,Na飗e Bayes(NB)classifier is used for the classification of detected waste objects into recyclable and non-recyclable ones.The performance validation of theDCNWO-RWOD technique takes place using the open access dataset.The extensive comparative study reported the enhanced performance of the DCNWO-RWOD technique interms of several measures.

Integrating the valence theory and the norm activation theory to understand consumers’ e-waste recycling intention

Electrical and electronic waste(e-waste)is a growing challenge,matching the widespread boom in the use of information and communication technology.Opposite to an alarming increasing amount of e-waste,a low rate of consumer engagement in ensuring the proper disposal of such materials intensifies the pressure on the exist‐ing e-waste crisis.To deal with this thorny problem,it is of great interest to grasp consumers’disposal and re‐cycling behavioral intentions.Therefore,this study attempts to understand complementary perspectives around consumers’e-waste recycling intention based on the integration of the valence theory and the norm activation theory.Four data mining models using classification and prediction-based algorithms,namely Chi squared automatic interaction detector(CHAID),Neural network,Discriminant analysis,and Quick,unbiased,efficient statistical tree(QUEST),were employed to analyze a set of the 398 data collected in Vietnam.The re‐sults revealed that the social support value is by far the most critical predictor,followed by the utilitarian value,task difficulty,and monetary risk.It is also noteworthy that the awareness of consequences,education background,the ascription of responsibility,and age were also ranked as critical affecting factors.The lowest influential predictors found in this study were income and gender.In addition,a comparison was made in terms of the classification performance of the four utilized data mining techniques.Based on several evalua‐tion measurements(confusion matrix,accuracy,precision,recall,specificity,F-measure,ROC curve,and AUC),the aggregated results suggested that CHAID and Neural network performed the best.The findings of this research are expected to assist policymakers and future researchers in updating all information surround‐ing consumer behavioral intention-related topics focusing on e-waste.Furthermore,the adoption of data min‐ing algorithms for prediction is another insight of this study,which may shed the light on data mining applica‐tions in such environmental studies in the future.

High-Throughput Pb Recycling for Perovskite Solar Cells Using Biomimetic Whitlockite

Pb contamination in aquatic environments causes severe pollution;therefore,harmless absorbents are required.In this study,we report a novel synthesis of whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12)),which is the second most abundant biomineral in human bone,and its application as a high-performing Pb^(2+)absorbent.Hydroxyapatite(HAP)and WH are prepared via a simple precipitation method.The Pb2+absorption performance and mechanism of the synthesized biominerals are investigated in aqueous solutions at neutral pH.The results demonstrate that WH exhibits an excellent Pb2+absorption capacity of 2339 mg g^(−1),which is 1.68 times higher than the recorded value for HAP.Furthermore,the absorbed Pb^(2+) ions are recycled into high-purity PbI_(2).This is employed as a precursor for the fabrication of perovskite solar cells(PSCs),resulting in a conversion efficiency of 19.00%comparable to that of commercial PbI2 powder(99.99%purity).Our approach provides an efficient way to remove Pb^(2+)ions from water and reuse them in the recycling of PSCs.

Recycling Carbon Resources from Waste PET to Reduce Carbon Dioxide Emission:Carbonization Technology Review and Perspective

Greenhouse gas emissions from waste plastics have caused global warming all over the world,which has been a central threat to the ecological environment for humans,flora and fauna.Among waste plastics,waste polyethylene terephthalate(PET)is attractive due to its excellent stability and degradation-resistant.Therefore,merging China’s carbon peak and carbon neutrality goals would be beneficial.In this review,we summarize the current state-of-the-art of carbon emission decrease from a multi-scale perspective technologically.We suggest that the carbon peak for waste PET can be achieved by employing the closed-loop supply chain,including recycling,biomass utilization,carbon capture and utilization.Waste PET can be a valuable and renewable resource in the whole life cycle.Undoubtedly,all kinds of PET plastics can be ultimately converted into CO_(2),which can also be feedstock for various kinds of chemical products,including ethyl alcohol,formic acid,soda ash,PU,starch and so on.As a result,the closed-loop supply chain can help the PET plastics industry drastically reduce its carbon footprint.

Industrial Recycling Process of Batteries for EVs

The growing number of decarbonization standards in the transportation sector has resulted in an increase in demand for electric cars.Renewable energy sources have the ability to bring the fossil fuel age to an end.Electrochemical storage devices,particularly lithium-ion batteries,are critical for this transition’s success.This is owing to a combination of favorable characteristics such as high energy density and minimal self-discharge.Given the environmental degradation caused by hazardous wastes and the scarcity of some resources,recycling used lithium-ion batteries has significant economic and practical importance.Many efforts have been undertaken in recent years to recover cathode materials(such as high-value metals like cobalt,nickel,and lithium).Regrettably,the regeneration of lower-value-added anode materials(mostly graphite)has received little attention.However,given the widespread use of carbon-based materials and the higher concentration of lithium in the anode than in the environment,anode recycling has gotten a lot of attention.As a result,this article provides the most recent research progress in the recovery of graphite anode materials from spent lithium ion batteries,analyzing the strengths and weaknesses of various recovery routes such as direct physical recovery,heat treatment recovery,hydrometallurgy recovery,heat treatment-hydrometallurgy recovery,extraction,and electrochemical methods from the perspectives of energy,environment,and economy;additionally,the reuse of recycled anode mats is discussed.Finally,the problems and future possibilities of anode recycling are discussed.To enable the green recycling of wasted lithium ion batteries,a low energy-consuming and ecologically friendly solution should be investigated.

Investigation and Benefits of the Use of Enzymes for Unbleached Kraft Recycling Wet Strength Paper at Lab and Industrial Scale

The deterioration of recycled fibers especially unbleached kraft with high wet strength resin content due to the irreversible structural changes caused by drying and added chemicals makes the raw material difficult to repulp.The mechanical effect in the pulper over time with chemical treatment has a negative impact on the recycled fibers.At lab scale,different compositions of enzymatic treatment C022L were under investigation to select the most efficient laccase Lacc1,Lacc2 or Lacc3 and to observe the impact of lipases during repulping at low and high consistencies.Pulp disintegration at different times was evaluated to define the level of rejects and to analyze the morphology of fibers after treatments.These results were more significant for Lacc2,by increasing the pulp consistency to 15%in the pulper.Combining lipases with CELODASE 022L appeared to decrease the efficiency of enzymes.The results showed a high reduction of energy power with the enzymatic treatment and a significant reduction of fines level in fibers’suspension.The most efficient version of C022L was used at industrial scale to compare directly with the standard conditions used in a paper mill.