Lithium-ion battery recycling: a source of per- and polyfluoroalkyl substances (PFAS) to the environment?

A Critical Review of Populations with Occupational Exposure to Per- and Polyfluoroalkyl Substances: External Exposome, Internal Exposure Levels, and Health Effects

The relationship between per- and polyfluoroalkyl substances (PFAS) exposure and human health has received widespread attention. This review focuses on the key distinctions in PFAS exposure between the occupational population and the general population from different countries. A systematic summary is made from the external exposure environment, exposure pathways, internal exposure levels, and health effects of the occupational population. The manufacturing, use, and disposal processes of PFAS increase their concentration levels in the ambient environment, leading to significantly higher concentrations than background areas. Different PFAS exposure pathways may lead to different molecular initiating events and health outcomes in the occupational population and the general population. Moreover, the PFAS exposure levels of the occupational population are nearly one hundred times higher than those of the general population. Mixed exposure to more unknown PFAS is another important feature of the occupational population. Although occupational exposure to PFAS is not associated with mortality, PFAS exposure can significantly disrupt metabolic pathways and cause adverse effects on the liver, kidney, and lipid homeostasis. Therefore, more stringent occupational protections for the PFAS occupational population are necessary to reduce their health risks.

Solvent-free Electrode Fabrication for Next-generation Batteries: Inception or an Endgame?

Solvent-free electrode fabrication (SEF) is a revolutionary advancement in the field of battery manufacturing, providing a compelling, solvent-free alternative to conventional slurry-based processing. SEF offers significant benefits, including reduced energy consumption resulting from the elimination of toxic solvents, solvent recovery steps, a lower environmental impact, overall cost reduction, and overcoming of binder migration, encountered during the fabrication of thicker electrodes. However, the practical application of SEF must overcome key challenges, such as achieving uniform particle distribution, ensuring strong electrode cohesion and adhesion, and scaling up to meet industrial production demands. This review provides a comprehensive assessment of the current landscape in dry electrode fabrication technologies, featuring advanced techniques such as dry pressing, spray dry deposition, and 3D printing. The fundamental chemistry of materials in addition to the mechanical, and electrochemical factors critical for optimizing battery performance is elaborated with a clear focus on lithium-ion batteries (LIBs) from lab to manufacturing stage. Moreover, the article highlights significant recent advancements, identifies critical technical barriers, and outlines imperative research directions necessary to unleash the full potential of dry electrode manufacturing in the realm of sustainable energy storage.

Identification and environmental occurrence of novel per- and polyfluoroalkyl substances derived from lithium-ion battery

Global rise in electric vehicle adoption has prompted the rapid expansion of the lithium-ion battery (LIB) manufacturing and recycling industry. Many emerging classes of per- and polyfluoroalkyl substances (PFASs) have been incorporated into the LIB. However, the potential for PFAS emissions to the environment during the manufacturing and recycling processes of the LIB remains poorly understood. In this study, characteristic fragment ion-based non-target analysis was conducted to screen and identify unknown PFASs in surface water and sediment samples surrounding several LIB manufacturing and recycling factories. In total, 33 PFASs belonging to eight classes were identified in collected environmental samples with the confidence level of 1 - 3. Among these PFASs, environmental occurrence of N-ethyl perfluoromethanesulfonamide, N-hydroxymethyl trifluoromethanesulfonamide, and a series of bisperfluoroalkane sulfonimides (Bis-FASIs) is first discovered in this study. Furthermore, this study also investigated the sediment-water partitioning behaviors of these identified 33 PFASs. Results showed that the calculated mean log Koc values in all sampling regions ranged from 0.51 ± 0.16 to 3.5 ± 0.34 for C2-C12 perfluoroalkyl carboxylates, 1.0 ± 0.31 to 2.9 ± 0.35 for C1-C8 perfluoroalkyl sulfonates, 1.2 ± 0.20 to 2.1 ± 0.19 for C1-C4 perfluoroalkane sulfonamides, and 1.9 ± 0.35 to 3.3 ± 0.16 for Bis-FASIs. In general, the log Koc values of each class of PFASs linearly (p < 0.05) increased with increasing number of fluorinated carbons. This study discovered seven novel PFASs, which underscores the need to expand regulatory monitoring beyond legacy PFASs. The findings of this study also highlight the urgency of assessing ecological and human health risks posed by LIB-derived PFASs, particularly their potential for long-range transport and persistence in aquatic systems.

Plant Uptake of Persistent and Mobile Chemicals in Rocket (Eruca sativa)─A Greenhouse Study on Agricultural Wastewater Reuse

With increasing water stress, agricultural wastewater reuse is becoming more prevalent worldwide. In this context, persistent and mobile (PM) chemicals may be especially relevant, yet data on their uptake by plants are still scarce. This study investigates the uptake of 61 PM chemicals by and distribution in rocket (Eruca sativa) in pot experiments from spiked water and treated municipal wastewater. The relative uptake (RU; share of theoretical maximum uptake) into rocket exceeded 10% for 18 PM chemicals, among others, perfluoropropionic acid (72% RU), trifluoroacetic acid (67%), and tetrafluoroborate (40%). The median plant uptake (p ≤ 0.05) and translocation factor (p < 0.0001) were significantly higher for PM chemicals than reported for less polar chemicals into leafy greens from literature. Irrigation of rocket with reclaimed municipal wastewater resulted in the accumulation of 23 analytes. However, a toxicological threshold of concern approach showed that no critical exposure is reached for these compounds at normal consumption levels. Comparing wastewater treatment plant effluent concentrations with plant uptake data led to a prioritization of PM chemicals, which might be especially relevant for agricultural wastewater reuse and should be considered in risk assessment.

Roadmap to Catalytic Abatement of Gas Phase Per- and Polyfluoroalkyl Substances (PFAS)

While the outstanding stability of per- and polyfluoroalkyl substances (PFAS) paved the way for their widespread application in a huge variety of applications, it also resulted in their nickname "forever chemicals". The rising awareness for PFAS-related environmental and health concerns drives a discussion on the most effective ways to abate PFAS emissions into the environment, i.e. water, soil, and air, and remediation of contaminated matter. In order to address the knowledge gap regarding air pollution by PFAS, this minireview summarizes the current corpus of work in the field and outlines how catalysis can contribute to PFAS abatement in the gas phase. Beyond a mere collection of state-of-the-art knowledge, overarching challenges in catalytic PFAS removal are identified, spanning from fundamental organic and inorganic chemistry, i.e. C-F-bond activation, to heterogeneous catalysis, i.e. surface reactions at the gas-solid interface, to reaction engineering, i.e. scaling relations and technical hurdles. In addition, the article introduces concepts and workflows that aim at providing guidance during the design of technological solutions for the efficient control of gaseous PFAS emissions.

Formation and Evolution of the Solid Electrolyte Interphase on Silicon Electrodes from Fluorine-Free Electrolytes

With the increasing attention to energy storage solutions, a growing emphasis has been placed on environmentally compatible electrolytes tailored for lithium-ion batteries. This study investigates the surface behavior of Si wafers as model systems cycled with a fluorine-free electrolyte based on lithium bis(oxalato)borate (LiBOB), with and without the additive vinylene carbonate (VC). By utilizing operando X-ray reflectivity (XRR) and ex situ X-ray photoelectron spectroscopy (XPS), the intricate processes involved in solid electrolyte interphase (SEI) formation is elucidated, SiO2/Si (de)lithiation, and the impact of the VC additive. Three distinct stages in SEI evolution during lithiation and delithiation are identified: SEI formation, subsequent densification and growth, and decrease in SEI thickness during delithiation, which collectively demonstrate the breathing behavior of the SEI during cycling. The addition of VC is found to mitigate LiBOB decomposition during cycling and promote a smoother SEI layer. Moreover, lithium trapping within the Si wafer post-delithiation is observed for both electrolytes but to a lesser extent with the addition of VC. This study offers structural and chemical insights into the fundamental processes governing SEI formation and Si wafer (de)lithiation in LiBOB-based electrolytes, with implications for designing environmentally friendly lithium-ion batteries.

Emerging Trends and Future Opportunities for Battery Recycling

The global lithium-ion battery recycling capacity needs to increase by a factor of 50 in the next decade to meet the projected adoption of electric vehicles. During this expansion of recycling capacity, it is unclear which technologies are most appropriate to reduce costs and environmental impacts. Here, we describe the current and future recycling capacity situation and summarize methods for quantifying costs and environmental impacts of battery recycling methods with a focus on cathode active materials. Second use, electrification of pyrometallurgy and hydrometallurgy, direct recycling, and electrochemical recycling methods are discussed as leading-edge methods for overcoming state of the art battery recycling challenges. The paper ends with a discussion of future issues and considerations regarding solid-state batteries and co-optimization of battery design for recycling.

Current trends and patterns of PFAS in agroecosystems and environment: A review

Per- and polyfluoroalkyl substances (PFASs) are one of the more well-known highly persistent organic pollutants with potential risks to agroecological systems. These compounds are of global concern due to their persistence and mobility, and they often lead to serious impacts on environmental, agricultural, and human health. In the past 20 years, the number of science publications on PFAS has risen; despite this, certain fundamental questions about PFAS occurrence, sources, mechanism of transport, and impacts on agroecosystems and the societies dependent on them are still open and evolving. There is a lack of systematic and comprehensive analysis of these concerns in agroecosystems. Therefore, we reviewed the current literature on PFAS with a focus on agroecosystems; our review suggests that PFASs are nearly ubiquitous in agricultural systems. We found the current research has limitations in analyzing PFAS in complex matrices because of their small size, distribution, and persistence within various environmental systems. There is consistency in the properties and composition of PFAS in and around agroecosystems, suggesting evidence of shared sources and similar components within different tropic levels. The introduction of new and varied sources of PFAS appear to be growing, adding to their residual accumulation in environmental matrices and leading to possible new types of chemical compounds that are difficult to assess accurately. This review determines existing research trends, understands mechanisms and incidence of PFAS within agroecosystems and their impact on human health, and thereby recommends further studies to remedy research gaps.

PFAS-Free Energy Storage: Investigating Alternatives for Lithium-Ion Batteries

The class-wide restriction proposal on perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the European Union is expected to affect a wide range of commercial sectors, including the lithium-ion battery (LIB) industry, where both polymeric and low molecular weight PFAS are used. The PFAS restriction dossiers currently state that there is weak evidence for viable alternatives to the use of PFAS in LIBs. In this Perspective, we summarize both the peer-reviewed literature and expert opinions from academia and industry to verify the legitimacy of the claims surrounding the lack of alternatives. Our assessment is limited to the electrodes and electrolyte, which account for the most critical uses of PFAS in LIB cells. Companies that already offer or are developing PFAS-free electrode and electrolyte materials were identified. There are also indications that PFAS-free electrolytes are in development by at least one other company, but there is no information regarding the alternative chemistries being proposed. Our review suggests that it is technically feasible to make PFAS-free batteries for battery applications, but PFAS-free solutions are not currently well-established on the market. Successful substitution of PFAS will require an appropriate balance among battery performance, the environmental effects associated with hazardous materials and chemicals, and economic considerations.

Residential Garden Produce Harvested Near a Fluorochemical Manufacturer in North Carolina Can Be An Important Fluoroether Exposure Pathway

Dietary intake can be an important exposure route to per- and polyfluoroalkyl substances (PFASs). Little is known about the bioaccumulation of emerging per- and polyfluoroalkyl ether acids (PFEAs) in garden produce from PFAS-impacted communities and the associated dietary exposure risk. In this study, 53 produce samples were collected from five residential gardens near a fluorochemical manufacturer. Summed PFAS concentrations ranged from 0.0026 to 38 ng/g wet weight of produce, and water-rich produce exhibited the highest PFAS levels. The PFAS signature was dominated by PFEAs, and hexafluoropropylene oxide-dimer acid (commonly known as GenX) was detected in 72% of samples. Based on average measured GenX concentrations, chronic-exposure daily limits were as low as 289 g produce/day for children (3-6 yr). This analysis does not consider other PFEAs that were present at higher concentrations, but for which reference doses were not available. This study revealed that consuming residential garden produce grown in PFAS-impacted communities can be an important exposure pathway.

Per- and poly-fluoroalkyl substances (PFAS) sensing: A focus on representatively sampling soil vadose zones linked to nano-sensors

Per- and poly-fluoroalkyl substances (PFAS) are a group of organo-fluorine compounds that have been broadly used in consumer and industrial products spanning virtually all sectors. They can be found as surfactants, coatings and liners, polymer additives, fire retardants, adhesives, and many more. The chemical stability of the carbon fluorine bond and amphiphilic nature of PFAS result in their persistence and mobility in the environment via soil porewater, surface water and groundwater, with potential for adverse effects on the environment and human health. There is an emergent and increasing requirement for fast, low-cost, robust, and portable methods to detect PFAS, especially in the field. There may be thousands of PFAS compounds present in soil and water at extremely low concentration (0.01-250 ppb) that require measurement, and traditional technologies for continuous environmental sensing are challenged due to the complexity of soil chemistry. This paper presents a comprehensive review of potentially rapid PFAS measurement methods, focused on techniques for representative sampling of PFAS in porewater from contaminated soil, and approaches for pre-treatment of porewater samples to eliminate these interferences to be ready for PFAS-detecting sensors. The review discusses selectivity, a key factor underlying pre-treatment and sensing performance, and explores the interactions between PFAS and various sensors. PFAS chemical nano-sensors discussed are categorized in terms of the detection mechanism (electrochemical and optical). This review aims to provide guidance and outline the current challenges and implications for future routine PFAS sensing linked to soil porewater collection, to achieve more selective and effective PFAS sensors.

Identification of Emerging Per- and Polyfluoroalkyl Substances (PFAS) in E-waste Recycling Practices and New Precursors for Trifluoroacetic Acid

Electronic waste is an emerging source of per- and polyfluoroalkyl substance (PFAS) emissions to the environment, yet the contribution from hazardous recycling practices in the South Asian region remains unclear. This study detected 41 PFAS in soil samples from e-waste recycling sites in Pakistan and the total concentrations were 7.43-367 ng/g dry weight (dw) (median: 37.7 ng/g dw). Trifluoroacetic acid (TFA) and 6:2 fluorotelomer sulfonic acid emerged as the dominant PFAS, constituting 49% and 13% of the total PFAS concentrations, respectively. Notably, nine CF3-containing emerging PFAS were identified by the high-resolution mass spectrometry (HRMS)-based screening. Specifically, hexafluoroisopropanol and bistriflimide (NTf2) were consistently identified across all the samples, with quantified concentrations reaching up to 854 and 90 ng/g dw, respectively. This suggests their potential association with electronic manufacturing and recycling processes. Furthermore, except for NTf2, all the identified emerging PFAS were confirmed as precursors of TFA with molar yields of 8.87-40.0% by the TOP assay validation in Milli-Q water. Overall, this study reveals significant emission of PFAS from hazardous e-waste recycling practices and emphasizes the identification of emerging sources of TFA from precursor transformation, which are essential for PFAS risk assessment.

Solar Cell Enhancement from Supercritical CO2 Dye Surface Modification of Mesoporous TiO2 Photoanodes

In recent years, in an effort to reach Net Zero Emissions, there has been growing interest by various academic and industry communities to develop chemicals and industrial processes that are circular, sustainable and green. We report the rapid, simple and effective surface modification of a porous metal oxide with organic dyes using supercritical carbon dioxide (scCO2). Titanium dioxide (TiO2) photoanodes were coated in very short times, under mild conditions and the excess dye recovered afterwards for reuse. The process obviates the need for conventional toxic solvents, the generation of unwanted waste streams, and more importantly, we see an unexpected device performance enhancement of 212 and 163 % for TerCOOTMS, 2 a and TerCN/COOTBDMS, 4 dyes, respectively, when compared to the conventional solvent deposition method.

Evaluating Polyacrylic Acid as a Universal Aqueous Binder for Ni-Rich Cathodes NMC811 and Si Anodes in Full Cell Lithium-ion Batteries

Silicon (Si) and silicon/graphite (Si/Gr) composite anodes are promising candidates due to their high theoretical capacity, low operating potential and natural abundance for high energy density Li-ion batteries. Green electrode production, eliminating organic volatile solvents require advancement of aqueous electrodes. Engineering the binder plays a critical role for improving waterborne electrodes. Lithium substituted polyacrylic acid LiPAA has been demonstrated as a promising binder for Si/Gr anodes and for Ni-rich cathodes in different cell configurations. LiPAA is utilized to minimize the volume expansion during cycling for Si/Gr anodes. LiPAA is formed in situ during cathode slurry preparation to regulate the pH and dimmish the Li loss. Using advanced characterization techniques, we investigated the slurries, electrodes, and active material reaction with LiPAA and its effect to the cycling performance. Our results indicate that the performance of high Si containing anode is limited by the amount of Si in the electrode. The failure mechanism with respect to high Si content was studied thoroughly. Aqueous processed cathodes with LiPAA binder in combination with Si anodes outperformed NMP based cathodes. Hence, LiPAA was successfully utilized as an active binder for both a high Si containing anode and for a Ni rich cathode.

A closer look at lithium-ion batteries in E-waste and the potential for a universal hydrometallurgical recycling process

The demand for lithium-ion batteries (LiBs) is rising, resulting in a growing need to recycle the critical raw materials (CRMs) which they contain. Typically, all spent LiBs from consumer electronics end up in a single waste stream that is processed to produce black mass (BM) for further recovery. It is desired to design a recycling process that can deal with a mixture of LiBs. Hence, this study investigates the structure and composition of battery modules in common appliances such as laptops, power banks, smart watches, wireless earphones and mobile phones. The battery cells in the module were disassembled into cell casing, cathode, anode and separator. Then, the cathode active materials (CAMs) were characterized in detail with XRD-, SEM-, EDX- and ICP-OES-analysis. No direct link was found between the chemistry of the active materials (NMC, LCO, LMO, LFP etc.) and the application. Various BM samples were submitted to a leaching procedure (2 M H2SO4, 50 °C, 2 h, 60 g BM/L) with varying concentration (0-4 vol%) of H2O2 to study the influence of their chemical composition on the dissolution of Li, Ni, Mn and Co. Only a part of the BMs dissolved completely at 4 vol% H2O2, which was attributed to the oxidation state of the transition metals (TMs). Exact determination of H2O2 consumption by redox titration confirmed this hypothesis.

Nontarget Analysis of Legacy and Emerging PFAS in a Lithium-Ion Power Battery Recycling Park and Their Possible Toxicity Measured Using High-Throughput Phenotype Screening

Driven by the global popularity of electric vehicles and the shortage of critical raw materials for batteries, the spent lithium-ion power battery (LIPB) recycling industry has exhibited explosive growth in both quantity and scale. However, relatively little information is known about the environmental risks posed by LIPB recycling, in particular with regards to perfluoroalkyl and polyfluoroalkyl substances (PFAS). In this work, suspect screening and nontarget analysis were carried out to characterize PFAS in soil, dust, water and sediment from a LIPB recycling area. Twenty-five PFAS from nine classes were identified at confidence level 3 or above, including 13 legacy and 12 emerging PFAS, as well as two ultrashort-chain PFAS. Based on the target analysis of 16 PFAS, at least nine were detected in each environmental sample, indicating their widespread presence in a LIPB recycling area. Perfluorodecanoic acid, perfluorooctanesulfonic acid and trifluoromethanesulfonamide showed significant differences in the four phenotypic parameters (growth, movement, survival and fecundity) of Caenorhabditis elegans and were the most toxic substances in all target PFAS at an exposure concentration of 200 μM. Our project provides first-hand information on the existence and environmental risk of PFAS, facilitating the formulation of regulations and green development of the LIPB recycling industry.

Lithium-ion battery components are at the nexus of sustainable energy and environmental release of per- and polyfluoroalkyl substances

Lithium-ion batteries (LiBs) are used globally as a key component of clean and sustainable energy infrastructure, and emerging LiB technologies have incorporated a class of per- and polyfluoroalkyl substances (PFAS) known as bis-perfluoroalkyl sulfonimides (bis-FASIs). PFAS are recognized internationally as recalcitrant contaminants, a subset of which are known to be mobile and toxic, but little is known about environmental impacts of bis-FASIs released during LiB manufacture, use, and disposal. Here we demonstrate that environmental concentrations proximal to manufacturers, ecotoxicity, and treatability of bis-FASIs are comparable to PFAS such as perfluorooctanoic acid that are now prohibited and highly regulated worldwide, and we confirm the clean energy sector as an unrecognized and potentially growing source of international PFAS release. Results underscore that environmental impacts of clean energy infrastructure merit scrutiny to ensure that reduced CO2 emissions are not achieved at the expense of increasing global releases of persistent organic pollutants.

Recycling of spent lithium-ion batteries for a sustainable future: recent advancements

Lithium-ion batteries (LIBs) are widely used as power storage systems in electronic devices and electric vehicles (EVs). Recycling of spent LIBs is of utmost importance from various perspectives including recovery of valuable metals (mostly Co and Li) and mitigation of environmental pollution. Recycling methods such as direct recycling, pyrometallurgy, hydrometallurgy, bio-hydrometallurgy (bioleaching) and electrometallurgy are generally used to resynthesise LIBs. These methods have their own benefits and drawbacks. This manuscript provides a critical review of recent advances in the recycling of spent LIBs, including the development of recycling processes, identification of the products obtained from recycling, and the effects of recycling methods on environmental burdens. Insights into chemical reactions, thermodynamics, kinetics, and the influence of operating parameters of each recycling technology are provided. The sustainability of recycling technologies (e.g., life cycle assessment and life cycle cost analysis) is critically evaluated. Finally, the existing challenges and future prospects are presented for further development of sustainable, highly efficient, and environmentally benign recycling of spent LIBs to contribute to the circular economy.

Evolving better solvate electrolytes for lithium secondary batteries

The overall performance of lithium batteries remains unmatched to this date. Decades of optimisation have resulted in long-lasting batteries with high energy density suitable for mobile applications. However, the electrolytes used at present suffer from low lithium transference numbers, which induces concentration polarisation and reduces efficiency of charging and discharging. Here we show how targeted modifications can be used to systematically evolve anion structural motifs which can yield electrolytes with high transference numbers. Using a multidisciplinary combination of theoretical and experimental approaches, we screened a large number of anions. Thus, we identified anions which reach lithium transference numbers around 0.9, surpassing conventional electrolytes. Specifically, we find that nitrile groups have a coordination tendency similar to SO2 and are capable of inducing the formation of Li+ rich clusters. In the bigger picture, we identified a balanced anion/solvent coordination tendency as one of the key design parameters.

Perfluorooctanesulfonic Acid Alters Pro-Cancer Phenotypes and Metabolic and Transcriptional Signatures in Testicular Germ Cell Tumors

The potential effects of poly- and perfluoroalkyl substances (PFAS) are a recently emergent human and environmental health concern. There is a consistent link between PFAS exposure and cancer, but the mechanisms are poorly understood. Although epidemiological evidence supporting PFAS exposure and cancer in general is conflicting, there is relatively strong evidence linking PFAS and testicular germ cell tumors (TGCTs). However, no mechanistic studies have been performed to date concerning PFAS and TGCTs. In this report, the effects of the legacy PFAS perfluorooctanesulfonic acid (PFOS) and the newer "clean energy" PFAS lithium bis(trifluoromethylsulfonyl)imide (LiTFSi, called HQ-115), on the tumorigenicity of TGCTs in mice, TGCT cell survival, and metabolite production, as well as gene regulation were investigated. In vitro, the proliferation and survival of both chemo-sensitive and -resistant TGCT cells were minimally affected by a wide range of PFOS and HQ-115 concentrations. However, both chemicals promoted the growth of TGCT cells in mouse xenografts at doses consistent with human exposure but induced minimal acute toxicity, as assessed by total body, kidney, and testis weight. PFOS, but not HQ-115, increased liver weight. Transcriptomic alterations of PFOS-exposed normal mouse testes were dominated by cancer-related pathways and gene expression alterations associated with the H3K27me3 polycomb pathway and DNA methylation, epigenetic pathways that were previously showed to be critical for the survival of TGCT cells after cisplatin-based chemotherapy. Similar patterns of PFOS-mediated gene expression occurred in PFOS-exposed cells in vitro. Metabolomic studies revealed that PFOS also altered metabolites associated with steroid biosynthesis and fatty acid metabolism in TGCT cells, consistent with the proposed ability of PFAS to mimic fatty acid-based ligands controlling lipid metabolism and the proposed role of PFAS as endocrine disrupters. Our data, is the first cell and animal based study on PFAS in TGCTs, support a pro-tumorigenic effect of PFAS on TGCT biology and suggests epigenetic, metabolic, and endocrine disruption as potential mechanisms of action that are consistent with the non-mutagenic nature of the PFAS class.

Exposure Assessment Study on Lithium-Ion Battery Fire in Explosion Test Room in Battery Testing Facility

A lithium-ion battery is a rechargeable battery that uses the reversible reduction of lithium ions to store energy and is the predominant battery type in many industrial and consumer electronics. The lithium-ion batteries are essential to ensure they operate safely. We conducted an exposure assessment five days after a fire in a battery-testing facility. We assessed some of the potentially hazardous materials after a lithium-ion battery fire. We sampled total suspended particles, hydrogen fluoride, and lithium with real-time monitoring of particulate matter (PM) 1, 2.5, and 10 micrometers (μm). The area sampling results indicated that primary potential hazardous materials such as dust, hydrogen fluoride, and lithium were below the recommended limits suggested by the Korean Ministry of Labor and the American Conference of Governmental Industrial Hygienists Threshold Limit Values. Based on our assessment, workers were allowed to return to work.

Alternatives to fluorinated binders: recyclable copolyester/carbonate electrolytes for high-capacity solid composite cathodes

Optimising the composite cathode for next-generation, safe solid-state batteries with inorganic solid electrolytes remains a key challenge towards commercialisation and cell performance. Tackling this issue requires the design of suitable polymer binders for electrode processability and long-term solid-solid interfacial stability. Here, block-polyester/carbonates are systematically designed as Li-ion conducting, high-voltage stable binders for cathode composites comprising of single-crystal LiNi0.8Mn0.1Co0.1O2 cathodes, Li6PS5Cl solid electrolyte and carbon nanofibres. Compared to traditional fluorinated polymer binders, improved discharge capacities (186 mA h g-1) and capacity retention (96.7% over 200 cycles) are achieved. The nature of the new binder electrolytes also enables its separation and complete recycling after use. ABA- and AB-polymeric architectures are compared where the A-blocks are mechanical modifiers, and the B-block facilitates Li-ion transport. This reveals that the conductivity and mechanical properties of the ABA-type are more suited for binder application. Further, catalysed switching between CO2/epoxide A-polycarbonate (PC) synthesis and B-poly(carbonate-r-ester) formation employing caprolactone (CL) and trimethylene carbonate (TMC) identifies an optimal molar mass (50 kg mol-1) and composition (wPC 0.35). This polymer electrolyte binder shows impressive oxidative stability (5.2 V), suitable ionic conductivity (2.2 × 10-4 S cm-1 at 60 °C), and compliant viscoelastic properties for fabrication into high-performance solid composite cathodes. This work presents an attractive route to optimising polymer binder properties using controlled polymerisation strategies combining cyclic monomer (CL, TMC) ring-opening polymerisation and epoxide/CO2 ring-opening copolymerisation. It should also prompt further examination of polycarbonate/ester-based materials with today's most relevant yet demanding high-voltage cathodes and sensitive sulfide-based solid electrolytes.

Nontarget Identification of Novel Per- and Polyfluoroalkyl Substances (PFAS) in Soils from an Oil Refinery in Southwestern China: A Combined Approach with TOP Assay

Oil refinery activity can be an emission source of perfluoroalkyl and polyfluoroalkyl substances (PFAS) to the environment, while the contamination profiles in soils remain unknown. This study investigated 44 target PFAS in soil samples collected from an oil refinery in Southeastern China, identified novel PFAS, and characterized their behaviors by assessing their changes before and after employing advanced oxidation using a combination of nontarget analysis and a total oxidizable precursor (TOP) assay. Thirty-four target PFAS were detected in soil samples. Trifluoroacetic acid (TFA) and hexafluoropropylene oxide dimer acid (HFPO-DA) were the dominant PFAS. Twenty-three novel PFAS of 14 classes were identified, including 8 precursors, 11 products, and 4 stable PFAS characterized by the TOP assay. Particularly, three per-/polyfluorinated alcohols were identified for the first time, and hexafluoroisopropanol (HFIP) quantified up to 657 ng/g dw is a novel precursor for TFA. Bistriflimide (NTf2) potentially associated with an oil refinery was also reported for the first time in the soil samples. This study highlighted the advantage of embedding the TOP assay in nontarget analysis to reveal not only the presence of unknown PFAS but also their roles in environmental processes. Overall, this approach provides an efficient way to uncover contamination profiles of PFAS especially in source-impacted areas.