Excellent Safety Performance Research Articles

Heterogeneous Engineering Strategy Derived In Situ Carbon-Encased Nickel Selenides Enabling Superior LIBs/SIBs with High Thermal Safety.

Nowadays, the extended usage of lithium/sodium ion batteries (LIBs/SIBs) encounters nerve-wracking issues, including a lack of suitable reservoirs and high thermal runaway hazards. Although using TiO2 and Li4Ti5O12 has been confirmed to be effective in improving battery safety, their low theoretical capacities inevitably cause damage to the electrochemical performance of the battery. Achieving win-win results has become an urgent necessity. This study designed a metal-organic framework (MOF)-derived in situ carbon-coated metal selenide (Ni-Se@G@C) as the anode. When the current density is 0.1-0.3 A g-1, the initial capacity of LIBs reaches 993.2 mAh g-1, which increases to 1478.9 mAh g-1 after running 800 cycles. When running at 2 A g-1, the cell also offers a relatively high capacity of 458.3 mAh g-1 after 1500 cycles. After the replacement of graphite with Ni-Se@G@C, the self-heating temperature (T0) and thermal runaway triggering temperature (T1) of half and full cells are significantly increased. Meanwhile, the maximum thermal runaway temperature (T2) and maximal heating release rate (HRRmax) are significantly reduced. Of note, the usage of Ni-Se@G@C enables the battery with superior cycling and rate performance. When used in SIBs, the cell gives an initial discharge capacity of 624.9 mAh g-1, which still remains at 269.4 mAh g-1 after running 200 cycles at 1 A g-1. Notably, Ea of the Ni-Se@G@C cell is 5.6 times higher than that of the graphite cell, corroborating the promoted safety performance. This work provides a new paradigm for MOF-derived micro/nanostructures, enabling the battery with an excellent electrochemical and safety performance portfolio.

R-Q@P-D nanoparticle for improving the oral bioavailability and therapeutic efficacy: A novel reversible dual-target-mild-inhibition intestinal metabolic enzymes strategy for resveratrol delivery

The low bioavailability of polyphenols, such as resveratrol (RES), is typically caused by the poor solubility and first-pass effect. To improve bioavailability and reduce adverse effects, an oral reversible UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) dual-target-mild-inhibition strategy was designed, and a proof-of-concept was studied. This R-Q@P-D nanoparticle for the codelivery of RES and quercetin (QUE) was constructed using pea protein isolate and dipotassium glycyrrhizinate (DG) as nanocarriers. These nanoparticle ingredients were all plant extracts approved by the FDA, and the fabrication process was a simple but novel pH-ultrasonic-shifting method in water conditions. R-Q@P-D exhibited high encapsulation efficiency of RES (97.25 ± 1.13 %) and QUE (94.21 ± 0.62 %), with a uniform nanosize (147.73 ± 1.85 nm). Characterizations implied that RES and QUE could be successfully encapsulated in nanoparticles in amorphous states, and the self-assembly binding between them was non-covalent bonds. Moreover, the in-silicon simulation and experimental results verified interactions between RES and DG, while there was no interaction between QUE and DG. In vivo evaluations showed that R-Q@P-D increased the bioavailability of RES by mildly and reversibly inhibiting intestinal UGTs and SULTs, but without inhibiting hepatic UGTs and SULTs. Moreover, molecular simulations showed that QUE and RES are competitively bound to SULTs but not UGTs. R-Q@P-D had significant therapeutic efficacy and excellent safety performance for its oral application. The tremendous safety and simple fabrication benefited the clinical translation. Together, R-Q@P-D based on reversible UGTs and SULTs dual-target-mild-inhibition strategy might be a promising nano-platform for improving the bioavailability and efficacy of hydrophobic polyphenols.

Unleashing Novel Therapeutic Strategies for Dry Eye: Targeting ROS and the cGAS-STING Signaling Pathway with Tetrahedral Framework Nucleic Acids.

Dry eye affects majority of the global population, causing significant discomfort or even visual impairment, of which inflammation plays a crucial role in the deterioration process. This highlights the need for effective and safe anti-inflammatory treatments to achieve satisfactory therapeutic outcomes. This study focuses on the potential of tetrahedral framework nucleic acids (tFNA), a self-assembled nucleic acid material, as a simple and rapid treatment for oxidative stress and inflammation-induced disorders associated with dry eye. Mechanistically, tFNA is found to effectively alleviate dry eye damage by promoting corneal epithelial healing, restoring goblet cell function, and facilitating tear secretion recovery. Through RNA-seq analysis, it is observed that tFNA treatment normalizes the expression levels of most genes. Further exploration of the mechanism reveals that tFNA reduces excessive production of reactive oxygen species and modulates the inflammatory microenvironment, especially through cGAS-STING pathway thereby levels of inflammatory cytokines, including MMP9 and IL-6, are reduced. Additionally, tFNA demonstrates excellent safety performance without causing damage to the eye. Importantly, this study represents a successful application of nanophase materials with nucleic acid biological features for the effective treatment of dry eye, highlighting the potential clinical use of tFNA in the treatment of dry eye.

Construction of composite self-assembly coating based on chitosan for enhancing the flame-retardant and antibacterial performances of cotton fabric

In this work, the step-by-step dip-coating (SBS) method was used to effectively improve the drawback of LBL by reducing the construction of a multilayer polyelectrolyte. Bio-based flame retardants, phytic acid (PA), and chitosan (CS) were further self-assembly on the surface of cotton fabric treated by epichlorohydrin-modified aramid nanofibers (AEP), ionic liquid (IL), and Cu ion. The pure cotton fabric was immersed in each dipping liquid only once, improving fire safety and antibacterial performance. The treated cotton self-extinguished with a 59 mm char length in the vertical flammability test, and the limiting oxygen index (LOI) value increased from 18.5 % to 38.5 %. The result of the cone calorimeter test (CCT) revealed that the fire hazard of flame-retardant cotton noteworthy declined (e.g., ~44.1 % and 55.4 % decline in peak heat release rate (pHRR) and total heat release rate (THR)). Conspicuously, the treated cotton exhibited a remarkably inhibiting effect on E. coli and S. aureus activity. The cotton fabric after flame-retardant finishing exhibited excellent fire safety and antibacterial performance.

Dendrite-Free Li5.5PS4.5Cl1.5-Based All-Solid-State Lithium Battery Enabled by Grain Boundary Electronic Insulation Strategy through In Situ Polymer Encapsulation.

Sulfide-based all-solid-state lithium batteries (ASSLBs) have attracted unprecedented attention in the past decade due to their excellent safety performance and high energy storage density. However, the sulfide solid-state electrolytes (SSEs) as the core component of ASSLBs have a certain stiffness, which inevitably leads to the formation of pores and cracks during the production process. In addition, although sulfide SSEs have high ionic conductivity, the electrolytes are unstable to lithium metal and have non-negligible electronic conductivity, which severely limits their practical applications. Herein, a grain boundary electronic insulation strategy through in situ polymer encapsulation is proposed for this purpose. A polymer layer with insulating properties is applied to the surface of the Li5.5PS4.5Cl1.5 (LPSC) electrolyte particles by simple ball milling. In this way, we can not only achieve a dense electrolyte pellet but also improve the stability of the Li metal anode and reduce the electronic conductivity of LPSC. This strategy of electronic isolation of the grain boundaries enables stable deposition/stripping of the modified electrolyte for more than 2000 h at a current density of 0.5 mA cm-1 in a symmetrical Li/Li cell. With this strategy, a full cell with Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) as the cathode shows high performance including high specific capacity, improved high-rate capability, and long-term stability. Therefore, this study presents a new strategy to achieve high-performance sulfide SSEs.

Bio-based P–N flame retardant with ZIF-67 in-situ growth on flexible polyurethane foam with excellent fire safety performance

The wide application of flexible polyurethane foam (FPUF) poses a giant challenge to human society in terms of fire prevention and environmental pollution. To solve this problem, the lignocellulose-based P–N flame retardant (LFPN) has been developed using mechanochemical methods. It was found that FPUF treated using LFPN exhibited good flame retardancy, but suffered from high smoke generation and toxicity. The hollow dodecahedral ZIF-67 has been used for smoke suppression catalysis, but the agglomeration phenomenon makes it inefficient. Hence, in this study, the adhesive properties of polydopamine (PDA) were utilized to assist the in-situ growth of ZIF-67. The results showed that the total smoke release rate of the treated FPUF was reduced by 40.5%. The toxic gases, such as carbon monoxide (CO), hydrogen cyanide, etc., also showed the same decreasing trend. What's more, the catalytic effect of ZIF-67 itself and the synergistic effect with LFPN gave FPUF great flame retardant and smoke inhibition properties. This novel FPUF provides a new reference for achieving smoke suppression and toxicity reduction.

Improved Collision Probability Analysis of the Double-Heterogeneity Problem Based on Matrix Chord Length Correction

Dispersion fuel exhibits excellent safety performance and effectively reduces the risk of radioactive leakage, making it widely applied in high-temperature gas-cooled reactors (HTGRs) and other advanced nuclear reactors. The presence of stochastic media in dispersion fuel leads to the challenging double-heterogeneity problem in neutron transport calculations. Hébert proposed a collision probability analysis model for treating stochastic media, which has been implemented in the DRAGON5 code. As one important basis of derivation, it is assumed in the Hébert model that the neutron transmission probability is identical to the neutron escaping probability in matrix material. In this paper, it is figured out that the assumption is not rigorous for realistic stochastic media. Then, an improved approach based on the Hébert model is proposed to take into account the realistic chord length distribution as well as to ensure the conservation and reciprocity of collision probabilities. The proposed methodology has been implemented in the HTGR lattice physics code XPZ. By numerical analysis against Monte Carlo reference solutions, it is demonstrated that the improved Hébert model with chord length correction gives good accuracy for addressing realistic double-heterogeneity problems.

Sound insulation enhancement of polyvinyl butyral film by blending polyurethane and its laminated safety glass

Laminated glass based on PVB film is widely used in military industry and life depending on its excellent safety performance. However, the insufficient sound insulation performance of PVB film restricts its practical application and has gained much more attention. In this work, a PVB-TPU composites with high strength and excellent sound insulation acoustic performance was designed by melt blending method which is attributed to their molecular entanglement and hydrogen bonding interactions between PVB and TPU molecule chains. It has been showed that the maximum tensile strength and elongation at break of the PVB-TPU blending film reached 34 MPa and 235 % respectively when 10 wt% content of TPU in the system. In addition, 20–41 dB of the sound transmission loss (TL) for the composite film with 1 mm thickness in the range of 2000–6000 Hz was achieved, which was obvious enhanced compared with the existing laminated glass intermediate film. The high impact resistance of the laminated glass based on the PVB-TPU film was confirmed by the falling ball impact test. The high sound insulation and safety laminated glass prepared here will be widely used in more fields.

Dual-Modified Electrospun Fiber Membrane as Separator with Excellent Safety Performance and High Operating Temperature for Lithium-Ion Batteries.

Polyacrylonitrile/Boric acid/Melamine/the delaminated BN nanosheets electrospun fiber membrane (PB3N1BN) with excellent mechanical property, high thermal stability, superior flame-retardant performance, and good wettability are fabricated by electrospinning PAN/DMF/H3BO3/C3H6N6/ the delaminated BN nanosheets (BNNSs) homogeneous viscous suspension and followed by a heating treatment. BNNSs are obtained by delaminating the bulk h-BN in isopropyl alcohol (IPA) with an assistance of Polyvinylpyrrolidone (PVP). Benefiting from the cross-linked pore structure and high-temperature stability of BNNSs, PB3N1BN electrospun fiber membrane delivers high thermal dimensional stability (almost no size contraction at 200°C), excellent mechanical property (19.1MPa), good electrolyte wettability (contact angle about 0°), and excellent flame retardancy (minimum total heat release of 3.2MJm-2). Moreover, the assembled LiFePO4/PB3N1BN/Li asymmetrical battery using LiFePO4 as the cathode and Li as the anode has a high capacity (169mAhg-1 at 0.5C), exceptional rate capability (129mAh g-1 at 5C), the prominent cycling stability without obvious decay after 400 cycles, and a good discharge capacity of 152mAh g-1 at a high temperature of 80°C. This work offers a new structural design strategy toward separators with excellent mechanical performance, good wettability, and high thermal stability for lithium-ion batteries.

Framework for the design of seismically isolated National Building Code of Canada Part 9 structures

In Canada, most single-family wood-frame residential structures in seismically hazardous regions are constructed according to Part 9 of Division B of the National Building Code (or similar provincial standards) using nonengineering methods. These structures are expected to perform well during an earthquake regarding life safety but may sustain severe economic losses. Seismic isolation is an emerging technology that provides excellent life safety and economic performance. While this technology has proven effective at protecting structures from earthquakes, no nonengineering methodologies exist that are compatible with Part 9 methods. This limitation produces significant testing, design, and cost barriers that restrict the application of base isolation on vulnerable Part 9 structures. To eliminate or reduce these cost barriers, a program framework was developed to perform the engineering seismic design and analysis for a base-isolated Part 9 single-family residential structure. The proposed methodology further encourages the application of seismic isolation to Part 9 structures.

Deprotonation-assisted electrochemical synthesis of copper nitrotriazole with excellent ignition performance

Electrochemical synthesis serves as a green and efficient method with great application potential. However, it has not been extensively applied in the synthesis of energetic materials. Nitrogen-rich heterocyclic compounds, as a new generation of energetic materials, enjoy advantages such as eco-friendliness, high energy output, and excellent safety performance. This study reports the electrochemical cathodic synthesis of copper nitrotriazole [Cu(NTz)2] using copper chloride and 3-nitro-1,2,4-triazole as a reaction substrate and triethylamine as a deprotonation agent. The obtained Cu(NTz)2 comprises uniform spherical particles of nano lamellae. As the dosage of triethylamine increased from 50 μL to 150 μL, Cu(NTz)2 gradually grew into compact solid spherical particles, significantly increasing the energy output. Notably, the heat release increased from 711 J g−1 to 1301 J g−1, accompanied by a significant positive elevation of ignition performance and peak combustion pressure in the process of confined combustion. This greatly boosted the energetic performance of Cu(NTz)2. Moreover, Cu(NTz)2 demonstrates insensitivity to electrostatic discharge (E50＞225 mJ) and friction (FS＞360 N), suggesting excellent safety performance. Owing to its outstanding energetic and safety performance, Cu(NTz)2 boasts great potential for application as pyrotechnic compositions, including military gas-producing and incendiary agents. Moreover, it has been corroborated that Cu(NTz)2 can be applied as a micro ignitor.

Embedding of Laser Generated TiO2 in Poly(ethylene oxide) with Boosted Li+ Conduction for Solid-State Lithium Metal Batteries.

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes are considered promising materials for realizing high-safety and high-energy-density lithium metal batteries. However, the high crystallinity of PEO at room temperature triggers low ionic conductivity and Li+ transference number, critically hindering practical applications in solid-state lithium metal batteries. Herein, we prepared nanosized TiO2 with enriched oxygen vacancies down to 13 nm as fillers by laser irradiation, which can be coated by in situ generated polyacetonitrile, ensuring good dispersibility in PEO. The electrolytes with nanosized TiO2 show a combination of high ionic conductivity, high Li+ transference number, superior electrochemical stability, and enhanced mechanical robustness. Accordingly, the lithium symmetric batteries with nanosized TiO2 composite solid electrolytes exhibit a stable cycling life up to 590 h at 0.25 mA cm-2. The full Li metal batteries paired with a LiFePO4 cathode deliver superior durability for 550 cycles. Moreover, the proof-of-concept pouch cells demonstrate excellent safety performance under various harsh conditions. This work provides a realistic guide in designing novel fillers to achieve stable operation of high-safety and energy-dense solid-state lithium metal batteries.

Design and preparation of a novel nano-composite coating for desensitization of CL-20

Although 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) is one of the best high-energy explosives, its application is severely limited by its high sensitivity. Herein, a composite wax-film with interfacial crosslinking anti-falling was designed and fabricated to desensitize CL-20. It was filled with nano-silica powder (n-Si), nano-graphenes (n-GPNs) and multi-walled carbon nanotubes (MWCNTs) as insensitive enhancers. A unique and stable core-shell composite explosive was prepared, and characterized by DSC, SEM, TEM, XRD, XPS as well as mechanical sensitivity tests. The results suggested that the functional group interaction and structural strengthening between enhancers and microcrystalline wax (MW) further enhanced the desensitization ability of the composite film for CL-20. Because of the hydrogen bonding and thickening enhancement, the CL-20 crystal was uniformly coated with a nano-composite film. Three enhancers were demonstrated to be highly compatible with CL-20. In comparison with MW@CL-20, The Ea, Tp0 and Tb of the composites containing n-GPNs increased by >375.27 kJ·mol−1, 21.04 °C and 18.27 °C, respectively. The SEM and XPS results showed that the composite performed a complete core-shell structure with thermal softening resistance and superior coverage (98.20 %). The insensitive enhancer was also distributed and embedded in the MW-film matrix. Besides, the anti-fall and cross-linking properties of the film enable the mechanical sensitivity of the composite explosive to reach to a level better than that of WO3/Al nanothermite with 5 wt% polyaniline and polymer-bonded explosive (PBX) with 95 wt% LLM-105 and 5 wt% ternary composite. The heterogeneous composites demonstrated excellent mechanical safety and high energy performance. These findings can provide a reference for the efficient desensitization of CL-20.

Comprehensive validation of early diagnostic algorithms for myocardial infarction in the emergency department.

To comprehensively evaluate diagnostic algorithms for myocardial infarction using a high-sensitivity cardiac troponin I (hs-cTnI) assay. We prospectively enrolled patients with suspected myocardial infarction without ST-segment elevation from nine emergency departments in Japan. The diagnostic algorithms evaluated: (i) based on hs-cTnI alone, such as the European Society of Cardiology (ESC) 0/1-h or 0/2-h and High-STEACS pathways; or (ii) used medical history and physical findings, such as the ADAPT, EDACS, HEART, and GRACE pathways. We evaluated the negative predictive value (NPV), sensitivity as safety measures, and proportion of patients classified as low or high-risk as an efficiency measure for a primary outcome of type 1 myocardial infarction or cardiac death within 30 days. We included 437 patients, and the hs-cTnI was collected at 0 and 1 hours in 407 patients and at 0 and 2 hours in 394. The primary outcome occurred in 8.1% (33/407) and 6.9% (27/394) of patients, respectively. All the algorithms classified low-risk patients without missing those with the primary outcome, except for the GRACE pathway. The hs-cTnI-based algorithms classified more patients as low-risk: the ESC 0/1-h 45.7%; the ESC 0/2-h 50.5%; the High-STEACS pathway 68.5%, than those using history and physical findings (15-30%). The High-STEACS pathway ruled out more patients (20.5%) by hs-cTnI measurement at 0 hours than the ESC 0/1-h and 0/2-h algorithms (7.4%). The hs-cTnI algorithms, especially the High-STEACS pathway, had excellent safety performance for the early diagnosis of myocardial infarction and offered the greatest improvement in efficiency.

Facile strategy of preparing excellently thermal-insulating and fire-safe building materials based on an aromatic Schiff base dicarboxylic acid without additional flame retardants

Developing excellently fire-safe and thermal-insulating building materials is a critical subject in the building sector. In this work, a novel aromatic Schiff base dicarboxylic acid (FN) was synthesized through a facile strategy to prepare high-performance rigid polyurethane foam (RPUF) composites with excellent thermal insulation and fire safety performance. The uniform dispersion of FN in polyether polyol improved the cellular structure of RPUF composites, which was conducive to increasing the thermal insulation of RPUF composites. Therefore, incorporating only 10 wt% FN into RPUF composite (RPUF/10FN) possessed the lowest wall temperature (51.9 °C) and room temperature (38.8 °C) with the lowest temperature growth rate under the continuous thermal radiation of the heat source among all samples in the small chamber test. Moreover, FN remarkably reduced the peak heat release rate, peak smoke production rate, and peak CO production rate of RPUF/10FN by 41.9%, 58.0%, and 59.6% without additional flame retardants, respectively, compared with those of pure RPUF. In addition, FN endowed RPUF/FN composites with better fire resistance and structural integrity compared with pure RPUF in the building facade fire test and fire protection test. The increased fire safety of RPUF/FN composites is due to the barrier effect of the formation of a dense and continuous char layer and the dilution effect of nonflammable gas generated by the thermal degradation of FN. Furthermore, FN enhanced the water contact angle of RPUF/FN composites from 112.2° for pure RPUF to 120.8° for RPUF/10FN, indicating that FN also enhanced the hydrophobicity of RPUF/FN composites. Therefore, the as-designed RPUF composites containing FN possessed a broad application prospect in the building field.

Nanophase separated, grafted alternate copolymer styrene-maleic anhydride as an efficient room temperature solid state lithium ion conductor

All solid-state lithium metal batteries (ASSLMBs) based on polymer solid electrolyte and lithium metal anode have attracted much attention due to their high energy density and intrinsic safety. However, the low ionic conductivity at room temperature and poor mechanical properties of the solid polymer electrolyte result in increased polarization and poor cycling stability of the Li metal batteries. In order to improve the ionic conductivity at room temperature while maintaining mechanical strength, we combine the conductivity of short chain polyethylene oxide (PEO) and strength of styrene-maleic anhydride copolymer (SMA) to obtain a grafted block copolymer with nanophase separation structure, which has room temperature ionic conductivity up to 1.14 × 10−4 S/cm and tensile strength up to 1.4 MPa. Li||Li symmetric cell can work stably for more than 1500 h under the condition of 0.1 mA/cm2. Li||LiFePO4 full cells can deliver a high capacity of 151.4 mAh/g at 25 °C and 0.2 C/0.2 C charge/discharge conditions, showing 85.6% capacity retention after 400 cycles. Importantly, the all solid state Li||LiFePO4 pouch cell shows excellent safety performance under different abuse conditions. These results demonstrate that the nanophase separated, grafted alternate copolymer electrolyte has huge potential for application in Li metal batteries.

Practical Application of All‐Solid‐State Lithium Batteries Based on High‐Voltage Cathodes: Challenges and Progress

AbstractAll‐solid‐state lithium batteries (ASSLBs) have become a recent research hotspot because of their excellent safety performance. In order to better reflect their superiority, high‐voltage cathodes should be applied to enhance the energy density of solid batteries to compete with commercial liquid batteries. However, the introduction of high‐voltage cathodes suffers from many problems, such as low electrochemical stability, inferior interface chemical stability between cathode and electrolyte, poor mechanical contact, and gas evolution. These drawbacks significantly influence the battery performance, even causing battery failure and hindering the commercialization of solid‐state batteries. This paper first reviews the above failure mechanisms of high‐voltage cathode‐based ASSLBs from different perspectives. Then, recent advances in solid‐state electrolytes for ASSLBs are summarized, mainly including polymer solid electrolytes, sulfide solid electrolytes, and oxide solid electrolytes. In addition, the influence of the cathode materials is also highly critical, and strategies to improve electrochemical performance are put forward, which can be divided into coating protection, synthesis modification, and structure improvement. Finally, guidelines for the future development of solid‐state batteries are also discussed.

Regulation of Lithium‐Ion Flux by Nanotopology Lithiophilic Boron‐Oxygen Dipole in Solid Polymer Electrolytes for Lithium‐Metal Batteries

Inhomogeneous lithium‐ion (Li+) deposition is one of the most crucial problems, which severely deteriorates the performance of solid‐state lithium metal batteries (LMBs). Herein, we discovered that covalent organic framework (COF‐1) with periodically arranged boron‐oxygen dipole lithiophilic sites could directionally guide Li+ even deposition in asymmetric solid polymer electrolytes. This in situ prepared 3D cross‐linked network Poly(ACMO‐MBA) hybrid electrolyte simultaneously delivers outstanding ionic conductivity (1.02 × 10−3 S cm−1 at 30 °C) and excellent mechanical property (3.5 MPa). The defined nanosized channel in COF‐1 selectively conducts Li+ increasing Li+ transference number to 0.67. Besides, The COF‐1 layer and Poly(ACMO‐MBA) also participate in forming a boron‐rich and nitrogen‐rich solid electrolyte interface to further improve the interfacial stability. The Li‖Li symmetric cell exhibits remarkable cyclic stability over 1000 h. The Li‖NCM523 full cell also delivers an outstanding lifespan over 400 cycles. Moreover, the Li‖LiFePO4 full cell stably cycles with a capacity retention of 85% after 500 cycles. the Li‖LiFePO4 pouch full exhibits excellent safety performance under pierced and cut conditions. This work thereby further broadens and complements the application of COF materials in polymer electrolyte for dendrite‐free and high‐energy‐density solid‐state LMBs.

Electrochemical activation strategy enabled ammonium vanadate cathodes for all-climate zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) have attracted significant attention for grid-scale energy applications due to their low cost, intrinsic safety, and environmental friendliness. However, the energy density of current ZIBs is impeded by unsatisfactory performance of cathodes, due to their limited areal capacity and low active material loading, especially at extreme environments. Herein, an electrochemical activation strategy is put forward to build high energy density ZIBs by designing a flexible cathode composed of NH4+ pillared ammonium vanadate nanosheets on carbon cloth (NVMCE@CC). The electrochemical activation process with high anodic potential (> 1.5 V vs. Zn2+/Zn) guarantees the effective conversion of low-valent to high-valent vanadium and promotes the utilization of large amounts of vanadium elements in the NVMCE@CC composite. Meanwhile, the pillared NH4+ ions expand the interlayer spacing and enhance the structural integrity through the hydrogen bonding between NH4+ and V-O framework. Consequently, the activated NVMCE@CC cathode with a high mass-loading of ∼5.2 mg cm−2 delivers large areal capacity (∼1.74 mAh cm−2 at 1 mA cm−2) and superior cycling stability (capacity retention of 72.1% after 1500 cycles). Importantly, the flexible cathode shows admirable capacities of 0.52 mAh cm−2 at 60 °C and 0.55 mAh cm−2 at − 10 °C, respectively. Moreover, the NVMCE@CC//Zn@CC quasi-solid-state battery demonstrates excellent safety performance and performs well in extreme situations, including bending, cutting, hammering, and washing. This work provides enlightenment for the development of large-areal-capacity vanadium-based cathode materials for practical ZIBs.

Facile fabrication of novel fire-safe MXene@IL-based epoxy nanocomposite coatings with enhanced thermal conductivity and mechanical properties

In recent years, developing high-performance epoxy nanocomposite coatings with excellent fire safety, thermal conductivity, and mechanical performance has become a thorny challenge. Here, the multifunctional nanohybrid (MXene@IL) was facilely fabricated by an electrostatic self-assembly strategy, and epoxy nanocomposite coatings based on MXene@IL (EP/MXene@IL) were prepared. It has been found that MXene@IL nanohybrids exhibit excellent dispersion and interfacial compatibility in the epoxy matrix. Notably, the 2.0 wt% MXene@IL endows the epoxy nanocomposite coating with high fire safety, with a 43.76 % reduction in peak heat release rate and a 65.99 % reduction in smoke factor compared to virgin epoxy resin (EP), respectively. Meanwhile, the thermal conductivity (increased by 21.56 %) of EP/MXene@IL-2.0 is enhanced. Furthermore, the flexural and impact strengths of EP/MXene@IL-1.0 are improved by 10.24 % and 44.73 %, respectively. Interestingly, MXene@IL acts as a co-curing agent to facilitate the curing reaction of epoxy nanocoatings. This work provides a feasible strategy for designing multifunctional MXene@IL-based epoxy nanocomposite coatings.