The association between brominated flame retardants exposure with bone mineral density in US adults: A cross-sectional study of the national health and nutrition examination survey (NHANES) 2005-2014.

BACKGROUND AND AIMS: Exposure to brominated flame retardants (BFRs) has been widely confirmed to impair the normal functioning of the human body system. However, there is a paucity of study on the effects of serum BFRs on bone mineral density (BMD). This study aims to investigate the relationship between exposure to BFRs and BMD in a nationally representative sample of U.S. adults. METHODS: 3079 participants aged between 20 and 80 years with complete data were included in the study. Serum levels of BFRs were measured using automated liquid-liquid extraction and subsequent sample clean-up. The BMD of all participants were assessed by DXA examinations. Generalize linear model, Restricted cubic spline (RCS), subgroup, weighted quantile sum (WQS) and bayesian kernel machine regression (BKMR) were used to estimate the association between serum BFRs and BMD. RESULTS: Multivariate linear regression analyses revealed that, after adjusting for covariates, PBB153 was significantly associated with TF-BMD (ß = 0.0177, 95%CI: 0.0103-0.0252), FN-BMD (ß = 0.009, 95%CI: 0.0036-0.0145), TS-BMD (ß = 0.0081, 95%CI: 0.0013-0.015) and L1-BMD (ß = 0.0144, 95%CI: 0.0075-0.0213). However, the associations lose their statistical significance after further adjustment for sex. BFRs exhibited S-shaped or line-plateau dose-response curves with BMD. In subgroup analyses, BFRs were significantly associated with BMD in participants who were younger than 55 years, female, overweight (BMI >25 kg/m2), and less alcohol consumption. In WQS and BKMR analyses, the effects of BFRs mixtures on BMD differed by sex, and PBDE153, PBDE209 and PBB153 had the highest weights in the WQS regression model. CONCLUSION: This study showed that serum BFRs negatively predicted BMD in men, but not in women or the general population. PBDE153, PBDE209, and PBB153 were significant BMD factors, especially in younger, overweight, and less alcohol consumption individuals.

Transforming a Primary Li-SOCl2 Battery into a High-Power Rechargeable System via Molecular Catalysis.

Li-SOCl2 batteries possess ultrahigh energy densities and superior safety features at a wide range of operating temperatures. However, the Li-SOCl2 battery system suffers from poor reversibility due to the sluggish kinetics of SOCl2 reduction during discharging and the oxidation of the insulating discharge products during charging. To achieve a high-power rechargeable Li-SOCl2 battery, herein we introduce the molecular catalyst I2 into the electrolyte to tailor the charging and discharging reaction pathways. The as-assembled rechargeable cell exhibits superior power density, sustaining an ultrahigh current density of 100 mA cm-2 during discharging and delivering a reversible capacity of 1 mAh cm-2 for 200 cycles at a current density of 2 mA cm-2 and 6 mAh cm-2 for 50 cycles at a current density of 5 mA cm-2. Our results reveal the molecular catalyst-mediated reaction mechanisms that fundamentally alter the rate-determining steps of discharging and charging in Li-SOCl2 batteries and highlight the viability of transforming a primary high-energy battery into a high-power rechargeable system, which has great potential to meet the ever-increasing demand of energy-storage systems.

Cation Co-Intercalation with Anions: The Origin of Low Capacities of Graphite Cathodes in Multivalent Electrolytes.

Dual-ion batteries involving anion intercalation into graphite cathodes represent promising battery technologies for low-cost and high-power energy storage. However, the fundamental origins regarding much lower capacities of graphite cathodes in earth abundant and inexpensive multivalent electrolytes than in Li-ion electrolytes remain elusive. Herein, we reveal that the limited anion-storage capacity of a graphite cathode in multivalent electrolytes is rooted in the abnormal multivalent-cation co-intercalation with anions in the form of large-sized anionic complexes. This cation co-intercalation behavior persists throughout the stage evolution of graphite intercalation compounds and leads to a significant decrease of sites practically viable for capacity contribution inside graphite galleries. Further systematic studies illustrate that the phenomenon of cation co-intercalation into graphite is closely related to the high energy penalty of interfacial anion desolvation due to the strong cation-anion association prevalent in multivalent electrolytes. Leveraging this understanding, we verify that promoting ionic dissociation in multivalent electrolytes by employing high-permittivity and oxidation-tolerant co-solvents is effective in suppressing multivalent-cation co-intercalation and thus achieving increased capacity of graphite cathodes. For instance, introducing adiponitrile as a co-solvent to a Mg2+-based carbonate electrolyte leads to 83% less Mg2+ co-intercalation and a ∼29.5% increase in delivered capacity of the graphite cathode.

Revealing Capacity Degradation of Ge Anodes in Lithium-Ion Batteries Triggered by Interfacial LiH.

The Germanium (Ge), as a fast-charging and high specific capacity (1568 mAh g-1 ) alloy anode, is greatly hampered in practical application by poor cyclability. To date, the understanding of cycling performance degradation remains elusive. This study illustrates that, contrary to conventional beliefs, most of the Ge material in failed anodes still retains good integrity and does not undergo severe pulverization. It is revealed that capacity degradation is clearly correlated to the interfacial evolution of lithium hydride (LiH). Tetralithium germanium hydride (Li4 Ge2 H), as a new species derived from LiH, is identified as the culprit of Ge anode degradation, which is the dominant crystalized component in an ever-growing and ever-insulating interphase. The significantly increased thickness of the solid electrolyte interface (SEI) is accompanied by the accumulation of insulating Li4 Ge2 H upon cycling, which severely retards the charge transport process and ultimately triggers the anode failure. We believe that the comprehensive understanding of the failure mechanism presented in this study is of great significance to promoting the design and development of alloy anode for the next generation of lithium-ion batteries.

Cathode Electrolyte Interphase (CEI) Endows Mo6 S8 with Fast Interfacial Magnesium-Ion Transfer Kinetics.

Magnesium (Mg) metal secondary batteries have attracted much attention for their high safety and high energy density characteristics. However, the significant issues of the cathode/electrolyte interphase (CEI) in Mg batteries are still being ignored. In this work, a significant CEI layer on the typical Mo6 S8 cathode surface has been unprecedentedly constructed through the oxidation of the chloride-free magnesium tetrakis(hexafluoroisopropyloxy)borate (Mg[B(hfip)4 ]2 ) salt under a proper charge cut-off voltage condition. The CEI has been identified to contain Bx Oy effective species originating from the oxidation of [B(hfip)4 ]- anion. It is confirmed that the Bx Oy species is beneficial to the desolvation of solvated Mg2+ , speeding up the interfacial Mg2+ transfer kinetics, thereby improving the Mg2+ -storage capability of Mo6 S8 host. The firstly reported CEI in Mg batteries will give deeper insights into the interface issues in multivalent electrochemical systems.

A Bio-Inspired Methylation Approach to Salt-Concentrated Hydrogel Electrolytes for Long-Life Rechargeable Batteries.

Hydrogel electrolytes hold great promise in developing flexible and safe batteries, but the presence of free solvent water makes battery chemistries constrained by H2 evolution and electrode dissolution. Although maximizing salt concentration is recognized as an effective strategy to reduce water activity, the protic polymer matrices in classical hydrogels are occupied with hydrogen-bonding and barely involved in the salt dissolution, which sets limitations on realizing stable salt-concentrated environments before polymer-salt phase separation occurs. Inspired by the role of protein methylation in regulating intracellular phase separation, here we transform the "inert" protic polymer skeletons into aprotic ones through methylation modification to weaken the hydrogen-bonding, which releases free hydrogen bond acceptors as Lewis base sites to participate in cation solvation and thus assist salt dissolution. An unconventionally salt-concentrated hydrogel electrolyte reaching a salt fraction up to 44 mol % while retaining a high Na+ /H2 O molar ratio of 1.0 is achieved without phase separation. Almost all water molecules are confined in the solvation shell of Na+ with depressed activity and mobility, which addresses water-induced parasitic reactions that limit the practical rechargeability of aqueous sodium-ion batteries. The assembled Na3 V2 (PO4 )3 //NaTi2 (PO4 )3 cell maintains 82.8 % capacity after 580 cycles, which is the longest cycle life reported to date.

A Multifunctional Polymer as an Interfacial Layer for Efficient and Stable Perovskite Solar Cells.

Metal-cation defects and halogen-anion defects in perovskite films are critical to the efficiency and stability of perovskite solar cells (PSCs). In this work, a random polymer, poly(methyl methacrylate-co-acrylamide) (PMMA-AM), was synthesized to serve as an interfacial passivation layer for synergistically passivating the under-coordinated Pb2+ and anchor the I- of the [PbI6 ]4- octahedron. Additionally, the interfacial PMMA-AM passivation layer cannot be destroyed during the hole transport layer deposition because of its low solubility in chlorobenzene. This passivation leads to an enhancement in the open-circuit voltage from 1.12 to 1.22 V and improved stability in solar cell devices, with the device maintaining 95 % of the initial power conversion efficiency (PCE) over 1000 h of maximum power point tracking. Additionally, a large-area solar cell module was fabricated using this approach, achieving a PCE of 20.64 %.

Highly Oxidative-Resistant Cyano-Functionalized Lithium Borate Salt for Enhanced Cycling Performance of Practical Lithium-Ion Batteries.

Lithium difluoro(oxalato) borate (LiDFOB) has been widely investigated in lithium-ion batteries (LIBs) owing to its advantageous thermal stability and excellent aluminum passivation property. However, LiDFOB tends to suffer from severe decomposition and generate a lot of gas species (e.g., CO2 ). Herein, a novel cyano-functionalized lithium borate salt, namely lithium difluoro(1,2-dihydroxyethane-1,1,2,2-tetracarbonitrile) borate (LiDFTCB), is innovatively synthesized as a highly oxidative-resistant salt to alleviate above dilemma. It is revealed that the LiDFTCB-based electrolyte enables LiCoO2 /graphite cells with superior capacity retention at both room and elevated temperatures (e.g., 80 % after 600 cycles) with barely any CO2 gas evolution. Systematic studies reveal that LiDFTCB tends to form thin and robust interfacial layers at both electrodes. This work emphasizes the crucial role of cyano-functionalized anions in improving cycle lifespan and safety of practical LIBs.

Gut microbiota and atopic dermatitis in children: a scoping review.

BACKGROUND: Gut microbiota plays an important role in the development of atopic dermatitis (AD). We aimed to elucidate research trends in gut microbiota and AD in children, to provide evidence and insights to the clinical prevention and treatment of AD in children. METHODS: A scoping literature review on the studies of gut microbiota and AD were conducted. Two authors independently searched Pubmed et al. databases for studies focused on gut microbiota and AD in children up to January 15, 2022. The literatures were screened and analyzed by two reviewers. RESULTS: A total of 44 reports were finally included and analyzed. Current researches have indicated that abnormal human microecology is closely associated with AD, and the disturbance of intestinal microbiota plays an important role in the occurrence and development of AD. Probiotics can correct the microbiota disorder, have the functions of regulating immunity, antioxidant, and help to restore the microecological homeostasis. However, there is still a lack of high-quality research reports on the efficacy and safety of probiotics in the prevention and treatment of AD in children. CONCLUSIONS: The changes of gut microbiota are essential to the development of AD in children, which may be an effective target for the prevention and treatment of AD. Future studies with larger sample size and rigorous design are needed to elucidate the effects and safety of probiotics in AD.

Eutectic Crystallization Activates Solid-State Zinc-Ion Conduction.

Solid-state zinc (Zn) batteries offer a new candidate for emerging applications sensitive to volume, safety and cost. However, current solid polymeric or ceramic electrolyte structures remain poorly conductive for the divalent Zn2+ , especially at room temperature. Constructing a heterogeneous interface which allows Zn2+ percolation is a viable option, but this is rarely involved in multivalent systems. Herein, we construct a solid Zn2+ -ion conductor by inducing crystallization of tailored eutectic liquids formed by organic Zn salts and bipolar ligands. High-entropy eutectic-networks weaken the ion-association and form interfacial Zn2+ -percolated channels on the nucleator surfaces, resulting in a solid crystal with exceptional selectivity for Zn2+ transport (t Zn 2 + =0.64) and appreciable Zn2+ conductivity (σ Zn 2 + =3.78×10-5  S cm-1 at 30 °C, over 2 orders of magnitude higher than conventional polymers), and finally enabling practical ambient-temperature Zn/V2 O5 metal solid cells. This design principle leveraged by the eutectic solidification affords new insights on the multivalent solid electrochemistry suffering from slow ion migration.

Polyacrylonitrile-Coordinated Perovskite Solar Cell with Open-Circuit Voltage Exceeding 1.23†V.

In solution-processed organic-inorganic halide perovskite films, halide-anion related defects including halide vacancies and interstitial defects can easily form at the surfaces and grain boundaries. The uncoordinated lead cations produce defect levels within the band gap, and the excess iodides disturb the interfacial carrier transport. Thus these defects lead to severe nonradiative recombination, hysteresis, and large energy loss in the device. Herein, polyacrylonitrile (PAN) was introduced to passivate the uncoordinated lead cations in the perovskite films. The coordinating ability of cyano group was found to be stronger than that of the normally used carbonyl groups, and the strong coordination could reduce the I/Pb ratio at the film surface. With the PAN perovskite film, the device efficiency improved from 21.58 % to 23.71 % and the open-circuit voltage from 1.12 V to 1.23 V, the ion migration activation energy increased, and operational stability improved.

The Formation/Decomposition Equilibrium of LiH and its Contribution on Anode Failure in Practical Lithium Metal Batteries.

Discovering the underlying reason for Li anode failure is a critical step towards applications of lithium metal batteries (LMBs). In this work, we conduct deuterium-oxide (D2 O) titration experiments in a novel on-line gas analysis mass spectrometry (MS) system, to determine the content of metallic Li and lithium hydride (LiH) in cycled Li anodes disassembled from practical LiCoO2 /Li LMBs. The practical cell is comprised of ultrathin Li anode (50 µm), high loading LiCoO2 (17 mg cm-2 , 2.805 mAh cm-2 ) and different formulated electrolytes. Our results suggest that the amount of LiH accumulation is negatively correlated with cyclability of practical LMBs. More importantly, we reveal a temperature sensitive equilibrium (Li + 1/2 H2 ⇌ LiH) governing formation and decomposition process of LiH at Li anode. We believe that the unusual understanding provided by this study will draw forth more insightful efforts to realize efficient Li protection and the ultimate applications of "holy grail" LMBs.

Leakage-Proof Electrolyte Chemistry for a High-Performance Lithium-Sulfur Battery.

Electrolyte leakage is a severe safety concern in lithium batteries. With highly volatile 1,2-dimethoxyethane as solvent, the leakage related hazards are more pronounced in lithium-sulfur (Li-S) batteries. To address this concern, a leakage-proof electrolyte is delicately designed through functionalizing the commercial electrolyte by Li6 PS5 Cl-grafted poly(ethyl cyanoacrylate), which can interact readily with the aluminum-plastic packing through hydrogen bond to immobilize the electrolyte. The moisture from ambient can also catalyze a further polymerization of the macromolecules to seal the leaking points and thereby to solve the leakage issue, endowing Li-S batteries superior safety even in an artificial cut pouch cell. With a bare S loading of 4.9 mg cm-2 , the battery can deliver good endurance owing to the suppressed polysulfide shuttle by its polar groups. This work enlightens the design of leakage-proof electrolyte and makes a milestone for high performance Li-S batteries.

A Novel Regulation Strategy of Solid Electrolyte Interphase Based on Anion-Solvent Coordination for Magnesium Metal Anode.

Magnesium (Mg) metal anode is a highly desirable candidate among various high energy density metal anodes, possessing higher volumetric capacity and better safety characteristic compared to lithium metal. However, most Mg salts in conventional Mg electrolytes easily react with Mg metal to form blocking layers, leading to inferior reversibility of Mg plating/stripping. Here, a stable Mg2+ -conducting solid electrolyte interphase (SEI) is successfully constructed on Mg metal anode by regulating the molecular-orbital-energy-level toward an aluminum(III)-centered anion Mg salt through anion-solvent coordination. Of which, the LUMO energy level of perfluorinated pinacolatoaluminate (Al(O2 C2 (CF3 )4 )2 - , abbreviated as FPA) anion has been adjusted by coordinating with solvent molecule (tetrahydrofuran) for facilitating the formation of advantageous SEI. The existence of SEI formed by FPA anion greatly improves the reversibility and long-term stability of Mg plating/stripping process. More importantly, based on this aluminum(III)-centered Mg electrolyte, the Mo6 S8 /Mg batteries can achieve a fantastic cycle performance of 9000 cycles, proving the beneficial effect of SEI on the cycling stability of Mg battery system. These findings open up a promising avenue to construct stable and compatible SEI on Mg metal anode, and lay significant foundations for the successful development of rechargeable Mg metal batteries.

A Polymer-Reinforced SEI Layer Induced by a Cyclic Carbonate-Based Polymer Electrolyte Boosting 4.45 V LiCoO2 /Li Metal Batteries.

Lithium (Li) metal batteries (LMBs) are enjoying a renaissance due to the high energy densities. However, they still suffer from the problem of uncontrollable Li dendrite and pulverization caused by continuous cracking of solid electrolyte interphase (SEI) layers. To address these issues, developing spontaneously built robust polymer-reinforced SEI layers during electrochemical conditioning can be a simple yet effective solution. Herein, a robust homopolymer of cyclic carbonate urethane methacrylate is presented as the polymer matrix through an in situ polymerization method, in which cyclic carbonate units can participate in building a stable polymer-integrated SEI layer during cycling. The as-investigated gel polymer electrolyte (GPE) assembled LiCoO2 /Li metal batteries exhibit a fantastic cyclability with a capacity retention of 92% after 200 cycles at 0.5 C (1 C = 180 mAh g-1 ), evidently exceeding that of the counterpart using liquid electrolytes. It is noted that the anionic ring-opening polymerization of the cyclic carbonate units on the polymer close to the Li metal anodes enables a mechanically reinforced SEI layer, thus rendering excellent compatibility with Li anodes. The in situ formed polymer-reinforced SEI layers afford a splendid strategy for developing high voltage resistant GPEs compatible with Li metal anodes toward high energy LMBs.

Highly Safe Electrolyte Enabled via Controllable Polysulfide Release and Efficient Conversion for Advanced Lithium-Sulfur Batteries.

Conventional lithium-sulfur batteries often suffer from fatal problems such as high flammability, polysulfide shuttling, and lithium dendrites growth. Here, highly-safe lithium-sulfur batteries based on flame-retardant electrolyte (dimethoxyether/1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether) coupled with functional separator (nanoconductive carbon-coated cellulose nonwoven) to resolve aforementioned bottle-neck issues are demonstrated. It is found that this flame-retardant electrolyte exhibits excellent flame retardancy and low solubility of polysulfide. In addition, Li/Li symmetrical cells using such flame-retardant electrolyte deliver extraordinary long-term cycling stability (less than 10 mV overpotential) for over 2500 h at 1.0 mA cm-2 and 1.0 mAh cm-2 . Moreover, bare sulfur cathode-based lithium-sulfur batteries using this flame retardant electrolyte coupled with nanoconductive carbon-coated cellulose separator can retain 83.6% discharge capacity after 200 cycles at 0.5 C. Under high charge/discharge rate (4 C), lithium-sulfur cells still show high charge/discharge capacity of ≈350 mAh g-1 . Even at an elevated temperature of 60 °C, discharge capacity of 870 mAh g-1 can be retained. More importantly, high-loading bare sulfur cathode (4 mg cm-2 )-based lithium-sulfur batteries can also deliver high charge/discharge capacity over 806 mAh g-1 after 56 cycles. Undoubtedly, the strategy of flame retardant electrolyte coupled with carbon-coated separator enlightens highly safe lithium-sulfur batteries at a wide range of temperature.

Anion Solvation Reconfiguration Enables High-Voltage Carbonate Electrolytes for Stable Zn/Graphite Cells.

Conventional carbonate solvents with low HOMO levels are theoretically compatible with the low-cost, high-voltage chemistry of Zn/graphite batteries. However, the nucleophilic attack of the anion on carbonates induces an oxidative breakdown at high potentials. Here, we restore the inherent anodic stability of carbonate electrolytes by designing a micro-heterogeneous anion solvation network. Based on the addition of a strongly electron-donating solvent, trimethyl phosphate (TMP), the oxidation-vulnerable anion-carbonate affinities are decoupled because of the preferential sequestration of anions into solvating TMP domains around the metal cations. The hybridized electrolytes elevate the electrochemical window of carbonate electrolytes by 0.45 V and enable the operation of Zn/graphite dual-ion cells at 2.80 V with a long cycle life (92 % capacity retention after 1000 cycles). By inheriting the non-flammability from TMP and the high ion-transport kinetics from the carbonate systems, this facile strategy provides cells with the additional benefits of fire retardancy and high-power capability.

Additive-Assisted Novel Dual-Salt Electrolyte Addresses Wide Temperature Operation of Lithium-Metal Batteries.

In this study, self-synthesized lithium trifluoro(perfluoro-tert-butyloxyl)borate (LiTFPFB) is combined with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to formulate a novel 1 m dual-salt electrolyte, which contains lithium difluorophosphate (LiPO2 F2 ) additive and dominant carbonate solvents with low melting point and high boiling point. The addition of LiPO2 F2 into this novel dual-salt electrolyte dramatically improves cycleability and rate capability of a LiNi0.5 Mn0.3 Co0.2 O2 /Li (NMC/Li) battery, ranging from -40 to 90 °C. The NMC/Li batteries adopt a Li-metal anode with low thickness of 100 µm (even 50 µm) and a moderately high cathode mass loading level of 10 mg cm-2 . For the first time, this paper provides valuable perspectives for developing practical lithium-metal batteries over a wide temperature range.

Fluorescence Probing of Active Lithium Distribution in Lithium Metal Anodes.

The uncontrollable growth of Li dendrites and the accumulation of byproducts are two severe concerns for lithium metal batteries, which leads to safety hazards and a low Coulombic efficiency. To investigate the deterioration of the cell, it is important to figure out the distribution of active Li species on the anode surface and distinguish Li dendrites from byproducts. However, it is still challenging to identify these issues by conventional visual observation methods. In this work, we introduce a novel fluorescent probing strategy using 9,10-dimethylanthracene (DMA). By marking the cycled Li-anode surface, the active Li distribution can be visualized by the fluorescence quenching of DMA reacting with active Li. The method demonstrates validity for electrolyte selection and predictive detection of uneven Li deposition on Li metal anodes. Furthermore, the location of dendrites can be clearly identified after destructive utilization of the anode, which will contribute to the development of failure-analysis technology for Li metal batteries.

In-Field, In Situ, and In Vivo 3-Dimensional Elemental Mapping for Plant Tissue and Soil Analysis Using Laser-Induced Breakdown Spectroscopy.

Sensing and mapping element distributions in plant tissues and its growth environment has great significance for understanding the uptake, transport, and accumulation of nutrients and harmful elements in plants, as well as for understanding interactions between plants and the environment. In this study, we developed a 3-dimensional elemental mapping system based on laser-induced breakdown spectroscopy that can be deployed in- field to directly measure the distribution of multiple elements in living plants as well as in the soil. Mapping is performed by a fast scanning laser, which ablates a micro volume of a sample to form a plasma. The presence and concentration of specific elements are calculated using the atomic, ionic, and molecular spectral characteristics of the plasma emission spectra. Furthermore, we mapped the pesticide residues in maize leaves after spraying to demonstrate the capacity of this method for trace elemental mapping. We also used the system to quantitatively detect the element concentrations in soil, which can be used to further understand the element transport between plants and soil. We demonstrate that this method has great potential for elemental mapping in plant tissues and soil with the advantages of 3-dimensional and multi-elemental mapping, in situ and in vivo measurement, flexible use, and low cost.