Search Results (91)

In this study, we investigate the environmental stability of the sulfide-based argyrodite solid electrolyte Li₆PS₅Cl₀.₅Br₀.₅, a promising candidate for all-solid-state lithium batteries due to its high ionic conductivity and favorable mechanical properties. Despite its potential, the material’s sensitivity to ambient air humidity presents challenges for large-scale battery manufacturing. Moisture exposure leads to performance degradation and the release of toxic hydrogen sulfide (H₂S) gas, raising concerns for workplace safety. The objectives of this study are to validate the electrolyte synthesis process, evaluate the effects of air humidity exposure on its reactivity and ionic conductivity, and establish a standardized protocol for assessing environmental stability. We report a synthesis method based on ball milling and heat treatment that achieves an ionic conductivity of 2.11 mS/cm, along with a fundamental study incorporating modeling and formulation approaches to evaluate the electrolyte’s environmental stability. Furthermore, we introduce a simplified testing method for assessing environmental stability, which may serve as a benchmark protocol for the broader class of argyrodite solid electrolytes. Full article

Removing residual energy from end-of-life batteries prior to transportation requires some method of deactivation. While many methods have been proposed, very few have been implemented due to limitations of cost, safety, and efficacy. In this work, multiple cell and battery types (e.g., lithium-polymer pouch cells, 18650 lithium-ion cell, alkaline batteries, and lithium-ion power-tool batteries) were deactivated using a low-cost and easily applied gel consisting of borax cross-linked polyvinyl alcohol and carbon. The PVA–carbon composite creates an external short-circuit pathway of moderate resistance that enables the complete discharge of batteries. Abusive testing conducted after deactivation demonstrates that hazards are largely eliminated, including a complete avoidance of thermal runaway from lithium-ion cells and a reduction in flammable and toxic gases by several orders of magnitude. Full article

The development of environmentally friendly pretreatment processes for spent lithium-ion batteries (LIBs) is crucial for optimizing direct recycling methods. This study explores alternative approaches for recovering active cathode materials from end-of-life LIBs, focusing on environmentally safer options compared to the usually employed toxic solvent N-methyl-pyrrolidone (NMP), using disassembled batteries as test subjects. Various pretreatment methods, including thermal treatment, selective aluminum foil dissolution with a NaOH solution, and the use of eco-friendly solvents such as triethyl phosphate (TEP), are examined on the cathode sheets. The results show that thermal pretreatment combined with TEP provides the most effective approach, achieving a recovery efficiency of 95% while maintaining the morphology and purity of the recovered materials, making them suitable for direct recycling. These methods are further tested on complete battery cells, simulating industrial-scale operations. The TEP treatment proves particularly promising, ensuring high recovery efficiency and preserving the structural integrity of the materials, with a mean particle diameter of approximately 8 µm. Additionally, when applied to cycled batteries, this pretreatment successfully recovers active materials without contamination. This study provides valuable insights into various pretreatment strategies, contributing to the development of a greener, more efficient direct recycling pretreatment process for spent LIBs. Full article

The advent of the lithium-ion batteries (LIBs) has transformed the energy storage field, leading to significant advances in electronics and electric vehicles, which continuously demand more and more performant devices. However, commercial LIB systems are still far from satisfying applications operating in arduous conditions, such as temperatures exceeding 100 °C. For instance, safety issues, materials degradation, and toxic stem development, related to volatile, flammable organic electrolytes, and thermally unstable salts (LiPF₆), limit the operative temperature of conventional lithium-ion batteries, which only occasionally can exceed 50–60 °C. To overcome this highly challenging drawback, the present study proposes advanced electrolyte technologies based on innovative, safer fluids such as ionic liquids (ILs). Among the IL families, we have selected ionic liquids based on tetrabutylphosphonium and 1-ethyl-3-methyl-imidazolium cations, coupled with per(fluoroalkylsulfonyl)imide anions, for standing out because of their remarkable thermal robustness. The thermal behaviour as well as the ion transport properties and electrochemical stability were investigated even in the presence of the lithium bis(trifluoromethylsulfonyl)imide salt. Conductivity measurements revealed very interesting ion transport properties already at 50 °C, with ion conduction values ranging from 10⁻³ and 10⁻² S cm⁻¹ levelled at 100 °C. Thermal robustness exceeding 150 °C was detected, in combination with anodic stability above 4.5 V at 100 °C. Preliminary cycling tests run on Li/LiFePO₄ cells at 100 °C revealed promising performance, i.e., more than 94% of the theoretical capacity was delivered at a current rate of 0.5C. The obtained results make these innovative electrolyte formulations very promising candidates for high-temperature LIB applications and advanced energy storage systems. Full article

Copper is widely used in both its metallic form and as oxide across numerous scientific and industrial domains. The primary copper oxides, cuprite (Cu₂O) and tenorite (CuO), naturally form on the copper surface and play a crucial role in advanced technologies, such as solar cells, lithium batteries, and sensors. Tenorite is appreciated for its optical properties, stability, low toxicity, and reactivity. While copper oxide thin films are traditionally synthesized through thermal treatments and oxidation in alkaline environments, these conventional high-temperature methods not only require significant energy consumption but can also compromise the metal–film interface. This study aims to develop a sustainable alternative approach for forming a homogeneous CuO layer on a copper substrate through environmentally friendly treatments based on low temperature, cost-effective, and time-saving procedures. Three different eco-conscious treatments were investigated: (i) immersion in NaOH basic solution, (ii) exposure to NaOH basic solution vapours, and (iii) a combined treatment involving both immersion and vapour exposure. This green synthesis approach significantly reduces energy consumption compared to traditional thermal methods while maintaining product quality. The surface oxide layer was investigated through an optical microscope (OM), scanning electron microscopy (SEM), spectrocolorimetric analysis, peel-off test, µ-Raman and X-ray photoelectron spectroscopy (XPS) analysis to investigate the surface oxidation state. Full article

Herein, we investigate the performance and safety of four of the early-stage, commercial Na-ion batteries available in 2024, representing the most popular cathode types across research and commercialization: polyanion (Na-VPF), layered metal oxide (Na-NMF), and a Prussian blue analog (Na-tmCN). The cells deliver a wide range of energy density with Na-tmCN delivering the least (23 Wh/kg) and Na-NMF delivering the most (127 Wh/kg). The Na-VPF cell was in between (47 Wg/kg). Capacity retention under specified cycling conditions and with periodic 0 V excursions was the most robust for the Na-tmCN cells in both cases. Accelerating rate calorimetry (ARC) and nail penetration testing finds that Na-NMF cells do undergo thermal runaway in response to abuse, while the Na-VPF and Na-tmCN exhibit only low self-heating rates (<1 °C/min). During these safety tests, all cells exhibited off-gassing, so we conducted in-line FTIR equipped with a heated gas cell to detect CO, CO₂, CH₄, toxic acid gases (HCN, HF, NH₃), and typical electrolyte components (carbonate ester solvents). Gases similar to those detected during Li-ion failures were found in addition to HCN for the Na-tmCN cell. Our work compares different types of commercial Na-ion batteries for the first time, allowing for a more holistic comparison of the safety and performance tradeoffs for different Na-ion cathode types emerging in 2024. Full article

We examined data from Naval Sea Systems Command grant project N0463A-12-C-001, “Hypercapnia: cognitive effects and monitoring”, with the objective of validating or repudiating heart rate variability (HRV) as a warning sign of cognitive impairment from diving gas narcosis or oxygen toxicity. We compared HRV feature scores to their temporally corresponding cognitive outcomes under normal and narcotizing conditions to identify specific HRV features associated with cognitive changes. N0463A-12-C-001 was conducted between 17 September 2013 and 29 January 2016 and employed NASA’s multi-attribute task battery (MATB-II) flight simulator to examine the independent effects of CO₂, N₂, and O₂ partial pressure on diver performance at simulated depths up to 61 msw (200 fsw). We assessed the association of 23 distinct HRV features scores from 432 of the study’s analyzable exposure stages in relation to MATB-II’s four performance subclasses (motor, memory, attention, strategy) while controlling for exercise and CO₂, N₂, and O₂ gas partial pressure. Performance decrements were associated with normalized high-frequency HRVfeatures (HFnu, p = 0.0016) and the number of pairs of successive R-R intervals that differed by more than 50 ms (NN50count1, p = 0.04). Secondary analysis with stratification restricted to non-exercise stages showed that several HRV parameters, including root mean square of the successive difference (RMSSD, p = 0.0015), width of Poincaré plot (p = 0.0017), NN50count1 (p = 0.0019), and standard deviation of normal-to-normal R peaks (p = 0.0082), were associated with performance impairment. The RMSSD association retained statistical significance after Bonferroni correction for multiple tests. HRV features collected from divers tested under narcotizing conditions of breathing gas partial pressure and exercise were associated with performance impairment. Full article

Bismine sodium salt (BSNa), a Schiff base with two sodium carboxylates, has shown promising electrochemical performance as an anode material. However, its synthesis involves toxic reagents and generates impurities, requiring significant solvent use for purification. This study introduces a novel synthetic method using sodium hydroxide as the sole reagent, which acts as both a base and Na source in the ion exchange step. With this procedure, we reduce the amounts of chemicals, diminish toxicity, improve the purity of the target compound, and use less solvent while maintaining comparable electrochemical performance. Additionally, the procedure is carried out under anhydrous conditions that avoid the undesirable hydrolysis of the imine linkages. In a previous report, the processing of the composite electrode was not established. In this article, we address this issue; the electrochemical performance, specifically the rate capability, is enhanced by processing the electrodes in laminate form rather than powder. As alternative to N-methyl-2-pyrrolidone (NMP), a common but disadvantageous solvent in laminate processing, other solvents were explored by testing acetone (DMK), methylisopropylketone (MIPK), and a DMK-NMP mixture. The remarkable electrochemical performance (specific capacity of 260–280 mAh/g, and capacity retentions higher than 84% at 1C (260 mA/g) remained consistent across these solvents. Furthermore, we investigated replacing copper with aluminum as the current collector to reduce costs and increase the energy density of the battery. While aluminum performed comparably to copper at low specific currents C/10 (26 mA/g), it showed a significant shift in the redox process potentials at higher specific currents. Full article

Renewable and non-renewable energy harvesting and its storage are important components of our everyday economic processes. Lithium-ion batteries (LIBs), with their rechargeable features, high open-circuit voltage, and potential large energy capacities, are one of the ideal alternatives for addressing that endeavor. Despite their widespread use, improving LIBs’ performance, such as increasing energy density demand, stability, and safety, remains a significant problem. The anode is an important component in LIBs and determines battery performance. To achieve high-performance batteries, anode subsystems must have a high capacity for ion intercalation/adsorption, high efficiency during charging and discharging operations, minimal reactivity to the electrolyte, excellent cyclability, and non-toxic operation. Group IV elements (Si, Ge, and Sn), transition-metal oxides, nitrides, sulfides, and transition-metal carbonates have all been tested as LIB anode materials. However, these materials have low rate capability due to weak conductivity, dismal cyclability, and fast capacity fading owing to large volume expansion and severe electrode collapse during the cycle operations. Contrarily, carbon nanostructures (1D, 2D, and 3D) have the potential to be employed as anode materials for LIBs due to their large buffer space and Li-ion conductivity. However, their capacity is limited. Blending these two material types to create a conductive and flexible carbon supporting nanocomposite framework as an anode material for LIBs is regarded as one of the most beneficial techniques for improving stability, conductivity, and capacity. This review begins with a quick overview of LIB operations and performance measurement indexes. It then examines the recently reported synthesis methods of carbon-based nanostructured materials and the effects of their properties on high-performance anode materials for LIBs. These include composites made of 1D, 2D, and 3D nanocarbon structures and much higher Li storage-capacity nanostructured compounds (metals, transitional metal oxides, transition-metal sulfides, and other inorganic materials). The strategies employed to improve anode performance by leveraging the intrinsic features of individual constituents and their structural designs are examined. The review concludes with a summary and an outlook for future advancements in this research field. Full article

Lithium-ion batteries (LIB) pose a safety risk due to their high specific energy density and toxic ingredients. Fire caused by LIB thermal runaway (TR) can be catastrophic within enclosed spaces where emission ventilation or occupant evacuation is challenging or impossible. The fine smoke particles (PM_2.5) produced during a fire can deposit in deep parts of the lung and trigger various adverse health effects. This study characterizes the chemical composition of PM_2.5 released from TR-driven combustion of cylindrical lithium iron phosphate (LFP) and pouch-style lithium cobalt oxide (LCO) LIB cells. Emissions from cell venting and flaming combustion were measured in real time and captured by filter assemblies for subsequent analyses of organic and elemental carbon (OC and EC), elements, and water-soluble ions. The most abundant PM_2.5 constituents were OC, EC, phosphate (PO₄³⁻), and fluoride (F⁻), contributing 7–91%, 0.2–40%, 1–44%, and 0.7–3% to the PM_2.5 mass, respectively. While OC was more abundant during cell venting, EC and PO₄³⁻ were more abundant when flaming combustion occurred. These freshly emitted particles were acidic. Overall, particles from LFP tests had higher OM but lower EC compared to LCO tests, consistent with the higher thermal stability of LFP cells. Full article

All novel materials should be analyzed for their potential environmental hazard. In this study, the toxicity of different silver–chitosan nanocomposites—potential candidates for wound dressings or antimicrobial surface coatings—was evaluated using environmentally relevant aquatic microcrustaceans Daphnia magna and Thamnocephalus platyurus and naturally luminescent bacteria Vibrio fischeri. Three silver-chitosan nanocomposites (nAgCSs) with different weight ratios of Ag to CS were studied. Citrate-coated silver nanoparticles (nAg-Cit), AgNO₃ (ionic control) and low molecular weight chitosan (LMW CS) were evaluated in parallel. The primary size of nAgCSs was ~50 nm. The average hydrodynamic sizes in deionized water were ≤100 nm, and the zeta potential values were positive (16–26 mV). The nAgCSs proved very toxic to aquatic crustaceans: the 48-h EC₅₀ value for D. magna was 0.065–0.232 mg/L, and the 24-h LC₅₀ value for T. platyurus was 0.25–1.04 mg/L. The toxic effect correlated with the shedding of Ag ions (about 1%) from nAgCSs. Upon exposure of V. fischeri to nAgCSs for 30 min, bacterial luminescence was inhibited by 50% at 13–33 mg/L. However, the inhibitory effect (minimum bactericidal concentration, MBC) on bacterial growth upon 1 h exposure was observed at higher concentrations of nAgCSs, 40–65 mg/L. LMW CS inhibited bacterial luminescence upon 30-min exposure at 5.6 mg/L, but bacterial growth was inhibited at a much higher concentration (1 h MBC > 100 mg/L). The multi-trophic test battery, where D. magna was the most sensitive test organism, ranked the silver-chitosan nanocomposites from ‘extremely toxic’ [L(E)C₅₀ ≤ 0.1 mg/L] to ‘very toxic’ [L(E)C₅₀ > 0.1–1 mg/L]. Chitosan was toxic (EC(L)₅₀) to crustaceans at ~12 mg/L, and ranked accordingly as ‘harmful’ [L(E)C₅₀ > 10–100 mg/L]. Thus, silver-chitosan nanocomposites may pose a hazard to aquatic organisms and must be handled accordingly. Full article

In this study, a flower-like Au/CeO₂ supported catalyst composite anode was prepared to explore its impact on thermal runaway triggered by overcharging and flame. Through structural and performance characterization, it was found that the catalyst has a high specific surface area and good CO catalytic oxidation capability, with a CO removal rate higher than 99.97% at room temperature. Through electrical performance testing, it was discovered that, compared to batteries without the catalyst, batteries using the composite anode did not exhibit significant capacity degradation. In overcharge testing, the catalyst prolonged the voltage rise time and peak voltage occurrence time of the battery. In thermal runaway testing, the addition of the catalyst delayed the detection time of CO and significantly reduced the concentration of thermal runaway products, especially the peak concentration and integrated concentration of CO, demonstrating its effectiveness in reducing thermal runaway products. Therefore, this study provides a new approach for improving the safety of lithium-ion batteries. The catalyst exhibits good performance in reducing toxic gases generated after thermal runaway and delaying the occurrence of thermal runaway, providing strong support for the safe application of lithium-ion batteries. Full article

Organophosphorus flame retardants (OPFRs) are abundant and persistent in the environment but have limited toxicity information. Their similarity in structure to organophosphate pesticides presents great concern for developmental neurotoxicity (DNT). However, current in vivo testing is not suitable to provide DNT information on the amount of OPFRs that lack data. Over the past decade, an in vitro battery was developed to enhance DNT assessment, consisting of assays that evaluate cellular processes in neurodevelopment and function. In this study, behavioral data of small model organisms were also included. To assess if these assays provide sufficient mechanistic coverage to prioritize chemicals for further testing and/or identify hazards, an integrated approach to testing and assessment (IATA) was developed with additional information from the Integrated Chemical Environment (ICE) and the literature. Human biomonitoring and exposure data were identified and physiologically-based toxicokinetic models were applied to relate in vitro toxicity data to human exposure based on maximum plasma concentration. Eight OPFRs were evaluated, including aromatic OPFRs (triphenyl phosphate (TPHP), isopropylated phenyl phosphate (IPP), 2-ethylhexyl diphenyl phosphate (EHDP), tricresyl phosphate (TMPP), isodecyl diphenyl phosphate (IDDP), tert-butylphenyl diphenyl phosphate (BPDP)) and halogenated FRs ((Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), tris(2-chloroethyl) phosphate (TCEP)). Two representative brominated flame retardants (BFRs) (2,2′4,4′-tetrabromodiphenyl ether (BDE-47) and 3,3′,5,5′-tetrabromobisphenol A (TBBPA)) with known DNT potential were selected for toxicity benchmarking. Data from the DNT battery indicate that the aromatic OPFRs have activity at similar concentrations as the BFRs and should therefore be evaluated further. However, these assays provide limited information on the mechanism of the compounds. By integrating information from ICE and the literature, endocrine disruption was identified as a potential mechanism. This IATA case study indicates that human exposure to some OPFRs could lead to a plasma concentration similar to those exerting in vitro activities, indicating potential concern for human health. Full article

The predicted increase in demand for minor metals for modern technologies raises major concerns regarding potential environmental concentration increases. Among the minor metals, lithium (Li) is particularly noteworthy due to growing demand for battery production. Concerns have been raised about the impact on biota of increasing Li concentrations in the environment. To expand the knowledge of the effects of Li on plants, garden cress (Lepidium sativum L.), a model plant for ecotoxicity assay, was tested in a 72 h test in Petri plates. The results showed a stimulation effect of Li at the lowest concentration (Li chloride 10 mg L⁻¹) on seed germination and primary root elongation. Conversely, higher Li concentrations (50 and 150 mg L⁻¹) caused a progressive impairment in both parameters. A genotoxic effect of Li on root cells, evaluated through the alkaline comet assay, was observed at each concentration tested, particularly at 150 mg L⁻¹ Li chloride. Elemental analysis showed that Li accumulated in the seedlings in a dose–concentration relationship, confirming its ability to be readily absorbed and accumulated in plants. Given the likely increase in Li levels in the environment, further research is required to clarify the toxicity mechanisms induced by Li on growth and nucleic acids. Full article

Per- and polyfluoroalkyl substances (PFAS) are widely used, and their fluorinated state contributes to unique uses and stability but also long half-lives in the environment and humans. PFAS have been shown to be toxic, leading to immunosuppression, cancer, and other adverse health outcomes. Only a small fraction of the PFAS in commerce have been evaluated for toxicity using in vivo tests, which leads to a need to prioritize which compounds to examine further. Here, we demonstrate a prioritization approach that combines human biomonitoring data (blood concentrations) with bioactivity data (concentrations at which bioactivity is observed in vitro) for 31 PFAS. The in vitro data are taken from a battery of cell-based assays, mostly run on human cells. The result is a Bioactive Concentration to Blood Concentration Ratio (BCBCR), similar to a margin of exposure (MoE). Chemicals with low BCBCR values could then be prioritized for further risk assessment. Using this method, two of the PFAS, PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonic Acid), have BCBCR values < 1 for some populations. An additional 9 PFAS have BCBCR values < 100 for some populations. This study shows a promising approach to screening level risk assessments of compounds such as PFAS that are long-lived in humans and other species. Full article