Triethyl Phosphate Research Articles

Influence of green solvents on the recovery of cathode active materials from electrode scraps: A comparative study

Direct recycling of cathode materials from spent Li-ion batteries (LIBs) or electrode scraps necessitates the efficient recovery of active materials from the aluminum foil. The variability in electrode types and recovery processes across previous studies complicates the comparative assessment of the recovery performance of green solvents. In this study, we evaluated the performance of three green solvents—triethyl phosphate (TEP), dihydrolevoglucosenone (Cyrene), and propylene carbonate (PC)—in recovering valuable active materials from industrial-grade cathode scraps. Using ultrasonication, we developed a standardized, energy-efficient recovery process that eliminated the need for conventional stirring and achieved complete cathode delamination from the aluminum foil. Furthermore, we successfully recovered the used green solvents after the process, ensuring their reuse and supporting a circular economy. The recovered materials retained their original morphology, chemical composition, and crystalline structure; however, the presence of surface impurities varied significantly depending on the green solvent used. These impurities had a considerable impact on the electrochemical performance of the recovered materials. TEP and PC yielded high-purity active materials and aluminum foils suitable for reuse or direct recycling, while Cyrene resulted in substantial residues of PVDF/solvent, requiring additional post-processing. Additionally, the recyclability of these green solvents was influenced by their solubility power for PVDF. This study provides valuable insights into the green solvent-based recycling process, laying the groundwork for future sustainable practices in LIB recycling.

Investigation of Electrolyte Salts in Non‐Flammable Triethyl Phosphate for Sodium‐Ion Batteries

Five different electrolyte salts, namely NaBF4, NaClO4, NaDFOB, NaFSI and NaPF6, were evaluated in non‐flammable triethyl phosphate (TEP) based electrolyte solutions in sodium‐ion full‐cells using high‐mass loading Prussian white and hard carbon electrodes. Their impact on the viscosity, ionic conductivity and solvation structure was analyzed, revealing that NaFSI‐based electrolytes exhibited a stronger interaction with TEP and less ion‐pairing than the other salts, resulting in the highest ionic conductivity at a concentration of 0.8 m (mol/kg). Galvanostatic cycling experiments showed that none of the electrolyte salts dissolved in TEP forms an efficient passivation layer. However, adding 1 wt.% vinylene carbonate (VC) significantly improved cycling performance for the cells with NaBF4, NaDFOB or NaFSI, but not with NaClO4 or NaPF6. Additionally, NaFSI in TEP with 1 wt.% VC electrolyte solution showed minimal gas evolution during the formation cycling (< 8 mbar). In a 1 Ah multilayer pouch cell, 0.8 m NaFSI in TEP with 1 wt.% VC showed promising results with 88% capacity retention after 200 cycles. X‐ray photoelectron spectroscopy analysis revealed that the addition of VC results in the formation of a thin SEI and minimized TEP decomposition on hard carbon, especially for 0.8 m NaFSI TEP with 1 wt.% VC.

Molecule-Level Multiscale Design of Nonflammable Gel Polymer Electrolyte to Build Stable SEI/CEI for Lithium Metal Battery

HighlightsNonflammable gel polymer electrolyte (SGPE) is developed by in situ polymerizing trifluoroethyl methacrylate (TFMA) monomers with flame-retardant triethyl phosphate (TEP) solvents and LiTFSI–LiDFOB dual lithium salts.Molecular polarity interaction between TEP and PTFMA mitigates interfacial reactions and changes the solvation of Li+.SGPE forms stable inorganic-rich solid electrolyte interface/cathode electrolyte interface layer, exhibiting well compatibility with Li anode and LiCoO2-type high-voltage cathode.

Occurrence and Distribution of Organophosphate Flame Retardants in Tap Water System-Implications for Human Exposure from Shanghai, China.

The pollution of organophosphate flame retardants (OPFRs) is of global concern, but the site-specific data of OPFR concentrations in drinking water are scarce for many areas of the world outside of Europe and the US. This study aimed to investigate the occurrence and profiles of OPFRs in the tap water treatment and delivery process in Shanghai. In total, 106 samples were analyzed for 10 OPFRs, which were collected periodically from monitoring points of drinking water treatment plants and piped water between November 2021 and July 2023. The average daily doses of OPFRs through the ingestion of tap water were calculated by multiplying nominal volumes of water ingestion rates with the measured concentrations of OPFRs. Hazard quotients, the hazard index, and the carcinogenic risks of OPFRs via drinking water were used to estimate the health risks. Tributyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP), and tris (1-chloro-2-propyl) phosphate (TCIPP) were found in >90% of the tap water samples, whereas triethyl phosphate (TEP) and tris (2,3-dibromopropyl) phosphate (TDBPP) were not found in any samples. The concentrations of Σ10OPFRs were found at part-per-trillion ranges, with average concentrations that ranged from 86.0 ng/L in February 2023 (dry season) to 218 ng/L in July 2022 (wet season). TCIPP was the most abundant compound among the investigated OPFRs. The average daily dose of Σ10OPFRs via the ingestion of tap water was up to 20.4 ng/kg body weight/day. The hazard quotients of OPFRs through drinking water were in the range of 10-5-10-4, indicating low risk levels. Moreover, the hazard index of OPFRs indicated that the risk for children (2 × 10-4) was higher than adults (7 × 10-5). Tap water intake may be an important source of OPFRs exposure. But the risk of OPFRs for local residents is at a low level through drinking water.

Plasticizers levels in four fish species from the Ligurian Sea and Central Adriatic Sea (Mediterranean Sea) and potential risk for human consumption

Plastic materials contain additives such as plasticizers and flame retardants, which are not covalently bound to plastic polymers and can therefore be unintentionally released into the marine environment. This study investigated three families of compounds, phthalates (PAEs), organophosphate esters (OPEs), and non-phthalate plasticizers (NPPs) currently used as plastic additives, in 48 muscle samples of bogue (Boops boops), European hake (Merluccius merluccius), red mullet (Mullus barbatus), and European pilchard (Sardina pilchardus) sampled in the Central Adriatic and the Ligurian Seas. The additional goal of this study is to assess the potential risk to human health from fish consumption with the objective of determining whether the detected levels might potentially pose a concern. PAEs represent the majority of the plastic additives detected in the selected species, with ubiquitous distribution across the study areas, whereas for OPEs and NPPs, there is a more pronounced difference between the two study areas, suggesting that these compounds may represent different exposure levels in the two seas. Among PAEs, bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and diisobutyl phthalate (DIBP) were the most abundant compounds, reaching levels up to 455 ng/g ww. OPEs were detected at higher concentrations in samples from the Ligurian Sea, and triethyl phosphate (TEP) was the most abundant compound. Among the NPPs, acetyl tributyl citrate (ATBC) was most frequently detected. From the results obtained, fish consumption may not pose a risk to human health (Hazard Quotient<1) but needs to be considered in future studies. Given the limited number of studies on PAEs, OPEs and NPPs in the Mediterranean Sea, further research is necessary to understand their potential bioaccumulation in marine organisms.

Ultra-high rate performance of single-crystalline NMC cathodes enabled by a TEP-based electrolyte

Harnessing the full potential of Ni-rich single-crystal cathodes (LiNixMnyCo1-x-yO2, NMC) for next-generation high-energy lithium batteries is hindered by their slow reaction kinetics and susceptibility to interfacial decay. Our research introduces a novel strategy utilizing triethyl phosphate (TEP) and fluoroethylene carbonate (FEC) to optimize the Li+ solvation environment, lowering the coordination number and diminishing the energy threshold for Li+ transport. Mechanistic studies indicate that this intervention not only accelerates the Li+ transfer at the electrode/electrolyte interface but also catalyzes the development of a robust LiF-rich CEI layer. As a result, the single-crystal NMC83 cathode exhibits remarkable high-rate discharge capacities of approximately 209 mAh g−1 at 0.1 C and 192 mAh g−1 at 0.5 C. The robust CEI layer also mitigates parasitic reactions, substantially improving the cycle life, with capacity retention increasing from 46.1 % to 88.2 % after 300 cycles at 1 C. This work underscores the transformative impact of solvation sheath engineering on the interfacial dynamics of single-crystal cathodes, paving the way for more durable and efficient energy storage solutions.

Structure-Dependent Distribution, Metabolism, and Toxicity Effects of Alkyl Organophosphate Esters in Lettuce (Lactuca sativa L.).

This study provides a comprehensive investigation into the structure-dependent uptake, distribution, biotransformation, and potential toxicity effects of alkyl organophosphate esters (OPEs) in hydroponic lettuce (Lactuca sativa L.). Trimethyl, triethyl, and tripropyl phosphates were readily absorbed and acropetally translocated, while tributyl, tripentyl, and trihexyl phosphates accumulated mainly in lateral roots. The acropetal translocation potential was negatively associated with log Kow values. Trimethyl and triethyl phosphates are less prone to biotransformation, while a total of 14 novel hydrolysis, hydroxylated, and conjugated metabolites were identified for other OPEs using nontarget analysis. The extent of hydroxylation decreases from tripropyl phosphate to trihexyl phosphate, but multiple hydroxylations occurred more frequently on longer chain OPEs. Further comparative toxicity test revealed that hydrolyzed and hydroxylated metabolites have stronger toxic effects on Ca2+-dependent protein kinases (CDPK) than their parent OPEs. Dibutyl 3-hydroxybutyl phosphate particularly induces upregulation of CDPK in lateral roots of lettuce, probably associated with adenine reduction that may play an important role in the self-defense and detoxification processes. This study contributes to understanding the uptake and transformation behaviors of alkyl OPEs as well as their associations with a toxic effect on lettuce. This emphasizes the necessary evaluation of the environmental risk of the use of OPEs, particularly focusing on their hydroxylated metabolites.

Zn-anode stability in additive added perchlorate electrolyte for aqueous Zn-MnO2 battery

Extensive research has been conducted on aqueous Zn-MnO2 batteries in the most common ZnSO4 electrolyte. However, the present study focuses on Zn anode stability and subsequent pairing with the commonly utilized MnO2 cathode in a low-concentration aqueous Zn (ClO4)2 electrolyte containing an organic additive, triethyl phosphate (TEP). The structural stability of Zn anodes in optimized additive-added and additive-free electrolytes is analyzed by assembling series of Zn∥Zn symmetry cells under various electrochemical conditions with varying depth of discharges between 20 and 60 %. As such, additive added electrolyte stabilizes the Zn anode over 250 h under high areal capacity/low areal current density of 38.3 mAh cm−2/11.3 mA cm−2 with 60 % depth of discharge at long half-cycle time of 29.5 h. The Zn-MnO2 paired cells in the Zn (ClO4)2 electrolyte with and without additives registered reversible capacities of 262 and 247 mAh g−1, respectively, at 0.05 A g−1. These electrochemical features are completely different from those of the common ZnSO4 electrolyte, whose electrochemical mechanism is still a subject of debate.

Chemical genetic analysis of enoxolone inhibition of Clostridioides difficile toxin production reveals adenine deaminase and ATP synthase as antivirulence targets

Toxins TcdA and TcdB are the main virulence factors of Clostridioides difficile, a leading cause of hospital-acquired diarrhea. Despite their importance, there is a significant knowledge gap of druggable targets for inhibiting toxin production. To address this, we screened non-antibiotic phytochemicals to identify potential chemical genetic probes to discover anti-virulence drug targets. This led to the identification of 18β-glycyrrhetinic acid (enoxolone), a licorice metabolite, as an inhibitor of TcdA and TcdB biosynthesis. Using affinity-based proteomics, potential targets were identified as ATP synthase subunit alpha (AtpA) and adenine deaminase (Ade, which catalyzes conversion of adenine to hypoxanthine in the purine salvage pathway). To validate these targets, a multi-faceted approach was adopted. Gene silencing of ade and atpA inhibited toxin biosynthesis, while SPR and ITC molecular interaction analyses revealed direct binding of enoxolone to Ade. Metabolomics demonstrated enoxolone induced the accumulation of adenosine, while depleting hypoxanthine and ATP in C. difficile. Transcriptomics further revealed enoxolone dysregulated phosphate uptake genes, which correlated with reduced cellular phosphate levels. These findings suggest that enoxolone's cellular action is multi-targeted. Accordingly, supplementation with both hypoxanthine and triethyl phosphate (TEP), a phosphate source, was required to fully restore toxin production in the presence of enoxolone. In conclusion, through the characterization of enoxolone, we identified promising anti-virulence targets that interfere with nucleotide salvage and ATP synthesis, which may also block toxin biosynthesis.

Preparation of high-performance PVDF hollow fiber microporous membranes via the c-TIPS process with water-insoluble solvent as the second solvent

Triethyl phosphate (TEP) is a promising solvent for the c-TIPS process given its high boiling point and water miscibility. However, casting solutions containing high TEP concentration generally trigger gelation, giving a dense outer surface in PVDF membrane. In this work, we fabricated PVDF hollow fiber membranes with a porous outer surface and excellent mechanical strength via a complex thermally induced phase separation (c-TIPS) method and applied them in the DCMD process. A water-insoluble solvent, dibasic ester solvents (DBEs), was used as the second solvent to modulate the phase separation process of the PVDF/TEP system. The mass transfer between the coagulation bath and the DBEs solvent was analyzed. It could decrease the polymer-solvent interactions and the rate of solvent efflux in the coagulation bath, contributing to the development of a porous membrane structure. When the weight ratio of TEP/DMA was 1, the optimized PVDF hollow fiber membrane exhibited a tensile strength of 8.34 MPa, an average pore diameter of 0.14 μm, giving the permeate flux of 18.56 ± 2.5 kg m−2 h−1 in DCMD and excellent operational stability when subjected to high brine concentration. Thus, the fabrication method shows a promising potential for tailoring the surface porosity and bulk structure. The PVDF membranes developed in this study demonstrate potential for use in membrane distillation and related applications.

Occurrence, Bioaccumulation, and Risk Assessment of Organophosphate Esters in Rivers Receiving Different Effluents.

Organophosphate esters (OPEs), as alternatives to brominated flame retardants, are extensively used in both production and daily life, with their environmental contamination and toxic effects being a concern. This study investigated the concentration levels, bioaccumulation, and ecological effects of OPEs in five different effluent-receiving rivers. The results demonstrate that the concentration range of Σ13OPEs across the five rivers was between 142.23 and 304.56 ng/L (mean: 193.50 ng/L). The highest pollution levels of OPEs were found in rivers receiving airport and industrial wastewater, followed by agricultural wastewater, mixed wastewater, and domestic wastewater. Tris(2-chloroisopropyl) phosphate (TCPP), triethyl phosphate (TEP), and tricresyl phosphate (TCrP) were identified as the main pollutants. The accumulation concentrations of OPEs in fish ranged from 54.0 to 1080.88 ng/g dw, with the highest bioaccumulation found in Pelteobagrus fulvidraco, followed by Carassius auratus and Misgurnus anguillicaudatus. The brain was the primary organ of accumulation, followed by the liver, gills, intestine, and muscle. Tri-n-propyl phosphate (TPeP) and TEP exhibited the highest bioconcentration, with log BAF values exceeding three. The bioaccumulation of OPEs was influenced by pollutant concentration levels, hydrophobic properties, and biological metabolism. Ecological risk assessment revealed that the cumulative risk values of Σ13OPEs ranged from 0.025 to 16.76, with TCrP being the major contributor. It posed a medium-low risk to algae but a high risk to crustaceans and fish.

Unveiling the occurrence and ecological risks of organophosphate esters in seawater of the northern South China Sea

As a class of emerging contaminants in marine environments, organophosphate esters (OPEs) have attracted increasing attention of environmental scientists and policymakers due to their ubiquity and ecotoxicity. However, little is known about the environmental geochemical behaviors of OPEs in seawater of the South China Sea (SCS). In this study, the concentration, composition, pollution source, and ecological risk of twelve typical OPEs were analyzed in the surface seawater of the northern SCS between August and September 2021. The results showed that five out of twelve OPEs were detectable with the total concentration of five OPEs (Σ5OPEs) ranging from 7.17 to 67.6 ng/L in seawater. Chlorinated OPEs (Cl-OPEs) were the predominant OPEs, with a mean concentration of 18.4 ng/L, accounting for more than 69.8 % of Σ5OPEs. Among the detected congeners, tris(2-chloroethyl) phosphate (TCEP) was the most abundant OPE (mean: 14.8 ng/L, 56.2 %), followed by triethyl phosphate (TEP) (mean: 7.75 ng/L, 29.5 %) and tris(1-chloro-2-propyl) phosphate (TCIPP) (mean: 2.07 ng/L, 7.87 %). Principal component analysis and Spearman correlation analysis indicated that terrestrial inputs, atmospheric deposition, and shipping activities were the potential sources of OPEs in the northern SCS. The ecological risk assessment revealed that TCEP posed low threats to algae and low ecological risks were predominantly observed from the mixture of OPEs. This work provides a basis for further investigation into the environmental behavior, toxicity, and risk of OPEs in the SCS and facilitates a better implementation of effective management actions.

High-Viscosity Phase Inversion Separators for Freestanding and Direct-on-Electrode Manufacturing in Lithium-Ion Batteries.

Separators play a critical role in lithium-ion batteries (LIBs) by facilitating lithium-ion (Li-ion) transport while enabling safe battery operation. However, commercial separators made from polypropylene (PP) or polyethylene (PE) impose a discrete processing step in current LIB manufacturing as they cannot be manufactured with the same slot-die coating process used to fabricate the electrodes. Moreover, commercial separators cannot accommodate newer manufacturing processes used to produce leading-edge microbatteries and flexible batteries with customized form factors. As a path toward rethinking LIB fabrication, we have developed a high-viscosity polymer composite separator slurry that enables the fabrication of both freestanding and direct-on-electrode films. A streamlined phase inversion process is used to impart porosity in cast separator films upon drying. To understand the impacts of material composition and rheology on phase inversion processing and separator performance, we investigated four different separator formulations. We used either diethylene glycol (DEG) or triethyl phosphate (TEP) as a nonsolvent, and either silica (SiO2) or alumina (Al2O3) as an inorganic additive in a polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix. Through a down-selection process, we developed a TEP-SiO2 separator formulation that matched or outperformed a commercial Celgard 2325 (PP/PE/PP) separator and a Beyond Battery ceramic-coated PE (CC/PE/CC) separator under rate and cycle life tests in LiFePO4|Li4Ti5O12 (LFP|LTO) and LiNi0.5Mn0.3Co0.2O2|graphite (NMC-532|graphite) coin cells at C/10-1C rates. Our TEP-SiO2 slurry had a viscosity of 298 Pa s at a 1 s-1 shear rate and shear-thinning behavior. When deposited directly onto an LTO anode and cycled against an LFP cathode, the direct-on-electrode TEP-SiO2 separator increased the specific capacity by 58% and 304% at 2C rates relative to the PP/PE/PP and CC/PE/CC separators, respectively. Additionally, the freestanding TEP-SiO2 separator maintained dimensional stability when heated to 200 °C for 1 h and demonstrated a higher elastic modulus and hardness than the PP/PE/PP and CC/PE/CC separators when measured with nanoindentation.

Structure-dependent destructive adsorption of organophosphate flame retardants on lipid membranes

The widespread use of organophosphate flame retardants (OPFRs), a serious type of pervasive environmental contaminants, has led to a global concern regarding their diverse toxicities to living beings. Using a combination of experimental and theoretical approaches, we systematically studied the adsorption, accumulation, and influence of a series of OPFRs on the lipid membranes of bacteria and cells. Our results revealed that OPFRs can aggregate in lipid membranes, leading to the destruction of membrane integrity. During this process, the molecular structure of the OPFRs is a dominant factor that significantly influences the strength of their interaction with the lipid membrane, resulting in varying degrees of biotoxicity. Triphenyl phosphate (TPHP), owing to its large molecular size and strong hydrophobicity, causes severe membrane disruption through the formation of nanoclusters. The corresponding severe toxicity originates from the phase transitions of the lipid membranes. In contrast, smaller OPFRs such as triethyl phosphate (TEP) and tris(2-chloroethyl) phosphate (TCEP) have weaker hydrophobicity and induce minimal membrane disturbance and ineffective damage. In vivo, gavage of TPHP induced more severe barrier damage and inflammatory infiltration in mice than TEP or TCEP, confirming the higher toxicity of TPHP. Overall, our study elucidates the structure-dependent adsorption of OPFRs onto lipid membranes, highlighting their destructive interactions with membranes as the origin of OPFR toxicity.

Non-Flammable Electrolyte for Large-Scale Ni-Rich Li-Ion Batteries: Reducing Thermal Runaway Risks

This research explores the properties and applications of flame-retardant esters (FREs), specifically triethyl phosphate (TEP) and tributyl phosphate (TBP), within electrolyte systems. The investigation assesses their roles as additives (30%v/v) and primary solvents (80%v/v) in conjunction with carbonate-based electrolytes (1.0 M LiPF6 in EC:DEC:EMC) and a novel non-flammable electrolyte formulation (1.2 M LiPF6 in 70%v/v TEP with 30%v/v fluoroethylene carbonate, FEC). Results indicate that incorporating FREs as additives adversely affects cell performance and maintain flammability risks, necessitating alternative strategies for achieving nonflammability. However, utilizing FREs as primary solvents alongside carbonate solvents shows promise for developing non-flammable electrolytes, despite concerns such as reductive decomposition that may limit suitability for certain battery cells. Conversely, the incorporation of 70%v/v FREs with 30%v/v FEC in the new electrolyte formulation yields a stable solid electrolyte interface, inhibiting FRE decomposition and sustaining battery cycling performance. This combination offers a potential solution for producing non-flammable electrolytes, serving as a viable alternative to solid-state electrolytes. The compatibility of the 1.2 M LiPF6 in TEP:FEC, 70:30 %v/v formulation with existing battery manufacturing processes further enhances its applicability. Figure 1

Organophosphate Esters in Raw Cow Milk and Cow's Drinking Water and Feed from China: Occurrence, Regional Distribution, and Dietary Exposure Assessment.

Organophosphate esters (OPEs) have been widely produced and used, while little is known about their occurrence in the food chain and potential sources. In this study, raw cow milk, cow drinking water, and feed were collected from pastures across China, and OPEs were tested to explore the occurrence and transmission of OPEs in the food chain and to further assess daily OPE intakes for cows and humans via certain food consumption. The median level of ∑OPEs (sum of 15 OPEs) in raw milk was 2140 pg/mL, and tris(1-chloro-2-propyl) phosphate (TCIPP) was the most abundant OPE. Levels of OPEs in water were lower than those in raw milk except for triethyl phosphate (TEP), while levels of most OPEs in feed were significantly higher than those in raw milk (adjusted by dry weight). The estimated dietary intake of OPEs via feed for cows was 2530 ng/kg bw/day, which was much higher than that via water (742 ng/kg bw/day), indicating that feed was a more critical exposure source. For liquid milk consumers, the high-exposure (95th) estimated daily intakes (EDIs) of ∑15OPE were 20 and 7.11 ng/kg bw/day for 3-17 years and adults, respectively, and it is obvious that cows had much heavier OPE intake. Finally, the calculated hazard indexes (HIs) suggested that the intake of OPEs via cow milk consumption would not pose significant health risks to the Chinese population.

Enhanced growth rates of N-type phosphorus-doped polycrystalline diamond via in-liquid microwave plasma CVD

Phosphorus-doped diamond (PDD) exhibits excellent properties, making it suitable for a wide range of applications, such as electronic devices and electrodes. Here, we report the first synthesis of PDD by in-liquid microwave plasma CVD (IL-MPCVD) under high-pressure and low-power conditions. A mixture of methanol (MeOH) and ethanol (EtOH) with triethyl phosphate ((C2H5)3PO4) and (P/C = 1000 ppm) was used for the PDD deposition. Samples were characterized by laser microscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. Notably, PDD was successfully produced at a growth rate of 280 μm/h, which is two orders of magnitude higher than conventional CVD methods. Additionally, cyclic voltammetry (CV) and impedance spectroscopy (EIS) were used to evaluate the electrochemical properties of PDD. As a result, we confirmed the wide potential window characteristic of conductive diamond and determined that the donor density was [P] = 3.8 × 1017cm⁻³. Therefore, it is clear that IL-MPCVD is applicable for very high growth rates in the CVD process for PDD synthesis.

Lightweight Electrolyte Design for Li/Sulfurized Polyacrylonitrile (SPAN) Batteries.

Sulfurized polyacrylonitrile (SPAN) recently emergesas a promising cathode for high-energy lithium (Li) metal batteries owing to its high capacity, extended cycle life, and liberty from costly transition metals. As the high capacities of both Li metal and SPAN lead to relatively small electrode weights, the weight and specific energy density of Li/SPAN batteries are particularly sensitive to electrolyte weight, highlighting the importance of minimizing electrolyte density. Besides, the large volume changes of Li metal anode and SPAN cathode require inorganic-rich interphases that can guarantee intactness and protectivity throughout long cycles. This work addresses these crucial aspects with an electrolyte design where lightweight dibutyl ether (DBE) is used as adiluent for concentrated lithium bis(fluorosulfonyl)imide(LiFSI)-triethyl phosphate (TEP) solution. The designed electrolyte (d = 1.04g mL-1) is 40%-50% lighter than conventional localized high-concentration electrolytes (LHCEs), leading to 12%-20% extra energy density at the cell level. Besides, the use of DBE introduces substantial solvent-diluent affinity, resulting in a unique solvation structure with strengthened capability to form favorable anion-derived inorganic-rich interphases, minimize electrolyte consumption, and improve cell cyclability. The electrolyte also exhibits low volatility and offers good protection to both Li metal anode and SPAN cathode under thermal abuse.

Monitoring of OPFRs in WWTPs: Unveiling environmental insights with high resolution mass spectrometry

Exploring the occurrence pattern of organophosphate flame retardants (OPFRs) in environmental samples has attracted increasing attention lately. In the conventional wastewater treatment plants (WWTPs), OPFRs are not sufficiently removed and therefore are discharged to the aquatic environment. However, concerns arise from their release regarding the potential risk posed to organisms. Consequently, closely monitoring this group of emerging contaminants, along with the evaluation of the associated ecological risk are matters of utmost importance. Given the aforementioned information, influents and effluents from two WWTPs (WWTP-A and WWTP-S) in Thessaloniki were gathered during a 36-month sampling initiative spanning from 2020 to 2023 in order to evaluate the occurrence and concentration levels of OPFRs. The collected samples underwent solid-phase extraction and then preceded to analysis with a Q Exactive Focus Orbitrap mass analyzer. In the present study, except for the implementation of the target analysis approach, removal efficiencies and mass loads were further calculated. TBEP (tris-2-butoxyethylphosphate) and TEP (triethyl phosphate) were detected in all influent samples (%DF = 100 %) in WWTP-A while in WWTP-S only TCPP (tris-1-chloro-2-propyl phosphate) was omnipresent. In effluents of both WWTPs, only TEP maintained the same detection frequency (%DF = 100 %). The highest mean concentration levels in WWTP-S influents were calculated for TEP (327 ng/L) followed by TCPP (277 ng/L) while in WWTP-A the highest mean concentrations in influents were detected for TCPP (405 ng/L) and TDCP (Tris(1,3-dichloro-2-propyl)phosphate) (124 ng/L). In effluents, the highest mean concentration was reported for TCPP, in both WWTPs, reaching 295 ng/L and 240 ng/L in WWTP-S and WWTP-A respectively. Generally, OPFRs exhibited low to moderate average removal efficiencies. Positive and negative removal efficiencies were also noticed during the monitoring campaign. The average mass load in WWTP-S was as high as 10.1 mg/day/1000 inhabitants and in WWTP-A, 11 mg/day/1000 inhabitants in effluents. Finally, different mathematical tools were employed for the assessment of the risk posed to algae, invertebrates and fish. For the toxicity assessment in these three trophic levels the worst-case scenario was taken into consideration. Generally, all the target analytes presented low or medium values in all trophic levels for acute and chronic toxicity.

Interfacial Decomposition Behaviour of Triethyl Phosphate‐Based Electrolytes for Lithium‐Ion Batteries

Triethyl phosphate (TEP) is a cheap, environmentally benign, and non‐flammable electrolyte solvent, whose implementation in lithium‐ion batteries is held back by its co‐intercalation into graphite anodes, resulting in exfoliation of the graphite structure. In this work, the electrode‐electrolyte interface behaviour of electrolytes containing up to 100% TEP was investigated and correlated to electrochemical performance. High capacity and stable cycling are maintained with up to 30% TEP in carbonate ester‐based electrolytes, but above this threshold the reversibility of Li+ intercalation into graphite drops sharply to almost zero. This represents a potential route to improved battery safety, while TEP can also improve safety indirectly by enabling the use of lithium bis(oxalato borate), a fluorine‐free salt with limited solubility in traditional electrolytes. To understand the poor performance at TEP concentrations of &gt;30%, its solvation behaviour and interfacial reaction chemistry were studied. Nuclear magnetic resonance spectroscopy data confirms changes in the Li+ solvation shell above 30% TEP, while operando gas analysis indicates extensive gas evolution from TEP decomposition at the electrode above the threshold concentration, which is almost entirely absent below it. X‐ray photoelectron spectroscopy depth profiling of electrodes demonstrates poor passivation by the solid electrolyte interphase above 30% TEP and significant graphite exfoliation.