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Polymer‐derived ceramics (PDCs) have become promising candidates for electromagnetic wave (EMW) absorption due to their high thermal stability, design flexibility, and versatile functionality. However, the inevitable porous structure formed during pyrolysis greatly limits its mechanical performance. In this work, Ni–Fe–C/HfO2/SiCN ceramic was prepared by simultaneously doping nickel and iron‐containing metal‐organic framework (Ni–Fe–MOF) nanoparticles and hafnium dioxide (HfO2) nanoparticles into the ceramic precursor, thereby improving its intrinsic brittle structure while granting it extraordinary EMW absorption performance. The flexural strength, flexural modulus, and Vickers hardness of Ni–Fe–C/HfO2/SiCN ceramic were 101.06 MPa, 40.19 GPa, and 13.31 GPa, respectively. These values were 1 132%, 749%, and 191% higher than those of the initial SiCN ceramics. In addition, by optimizing the content of Ni–Fe–MOF, the Ni–Fe–C/HfO2/SiCN ceramic demonstrated satisfying EMW absorption performance from 25°C to 500°C. At 25°C, the minimum reflection loss (RLmin) and effective absorption bandwidth (EAB) were −54.07 dB and 3.95 GHz, covering 94% of the X‐band at a thickness of 2.27 mm. At 500°C, the RLmin and EAB were −33.72 dB and 1.82 GHz, still covering 43% of the X‐band at a thickness of only 1.65 mm. This work provides valuable insight into the integration of mechanical and EMW absorbing functions of PDC materials. [ABSTRACT FROM AUTHOR]

Polymers are known to adsorb spontaneously from liquid solutions in contact with high‐energy substrates to form configurationally complex, but robust phases that often exhibit higher durability than might be expected from the individual physical bonds formed with the substrate. Rational control of the physical, chemical, and transport properties of such interphases has emerged as a fundamental opportunity for scientific and technological advances in energy storage technology but requires in‐depth understanding of the conformation states and electrochemical effect of the adsorbed polymers. Here, we analyze the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains of moderate sizes dissolved in protic and aprotic liquid electrolytes and find that there is an optimum polymer molecular weight of approximately 400 Da at which the highest columbic efficiency is achieved for both Zn and Li deposition. These findings point to a simple, versatile approach for extending the lifetime of batteries. [ABSTRACT FROM AUTHOR]

Polymers are known to adsorb spontaneously from liquid solutions in contact with high‐energy substrates to form configurationally complex, but robust phases that often exhibit higher durability than might be expected from the individual physical bonds formed with the substrate. Rational control of the physical, chemical, and transport properties of such interphases has emerged as a fundamental opportunity for scientific and technological advances in energy storage technology but requires in‐depth understanding of the conformation states and electrochemical effect of the adsorbed polymers. Here, we analyze the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains of moderate sizes dissolved in protic and aprotic liquid electrolytes and find that there is an optimum polymer molecular weight of approximately 400 Da at which the highest columbic efficiency is achieved for both Zn and Li deposition. These findings point to a simple, versatile approach for extending the lifetime of batteries. [ABSTRACT FROM AUTHOR]

Quaternary siliconboron carbonitride (SiBCN) ceramics show excellent high‐temperature stability and oxidation resistance, indicating great potential as high‐temperature electromagnetic (EM) wave absorbing materials. In this contribution, an efficient and facile method was developed to prepare bulk iron‐containing SiBCN (Fe–SiBCN) ceramics with remarkable EM wave absorption at high temperature by pyrolyzing boron and iron containing precursors (PSZV‐B–Fe). The introduction of boron and iron not only improves the high‐temperature stability but also influences the complex permittivity and EM wave absorption. The minimum reflection coefficient (RCmin) is −61.05 dB, and the effective bandwidth absorption (EAB) is 3.35 GHz (9.05–12.4 GHz). The RCmin will be decreased to −52.3 dB at 600°C as well as the EAB covers more than 67% of the X band (2.8 GHz). The high‐temperature stable Fe–SiBCN ceramics with adjustable dielectric properties can be utilized as high‐performance EM wave‐absorbing materials in high‐temperature and harsh environments. [ABSTRACT FROM AUTHOR]

LiNO3 is a widely used salt‐additive that markedly improves the stability of ether‐based electrolytes at a Li metal anode but is generally regarded as incompatible with alkyl carbonates. Here we find that contrary to common wisdom, cyclic carbonate solvents such as ethylene carbonate can dissolve up to 0.7 M LiNO3 without any additives, largely improving the anode reversibility. We demonstrate the significance of our findings by upgrading various state‐of‐the‐art carbonate electrolytes with LiNO3, which provides large improvements in batteries composed of thin lithium (50 μm) anode and high voltage cathodes. Capacity retentions of 90.5 % after 600 cycles and 92.5 % after 200 cycles are reported for LiNi0.6Mn0.2Co0.2O2 (2 mAh cm−2, 0.5 C) and LiNi0.8Mn0.1Co0.1O2 cathode (4 mAh cm−2, 0.2 C), respectively. 1 Ah pouch cells (≈300 Wh kg−1) retain more than 87.9 % after 100 cycles at 0.5 C. This work illustrates that reforming traditional carbonate electrolytes provides a scalable, cost‐effective approach towards practical LMBs. [ABSTRACT FROM AUTHOR]

LiNO3 is a widely used salt‐additive that markedly improves the stability of ether‐based electrolytes at a Li metal anode but is generally regarded as incompatible with alkyl carbonates. Here we find that contrary to common wisdom, cyclic carbonate solvents such as ethylene carbonate can dissolve up to 0.7 M LiNO3 without any additives, largely improving the anode reversibility. We demonstrate the significance of our findings by upgrading various state‐of‐the‐art carbonate electrolytes with LiNO3, which provides large improvements in batteries composed of thin lithium (50 μm) anode and high voltage cathodes. Capacity retentions of 90.5 % after 600 cycles and 92.5 % after 200 cycles are reported for LiNi0.6Mn0.2Co0.2O2 (2 mAh cm−2, 0.5 C) and LiNi0.8Mn0.1Co0.1O2 cathode (4 mAh cm−2, 0.2 C), respectively. 1 Ah pouch cells (≈300 Wh kg−1) retain more than 87.9 % after 100 cycles at 0.5 C. This work illustrates that reforming traditional carbonate electrolytes provides a scalable, cost‐effective approach towards practical LMBs. [ABSTRACT FROM AUTHOR]

Title compounds are conveniently and efficiently synthesized by the reaction of chalcones (I) and ammonium acetate or via one-pot three-component condensation of aromatic aldehydes with acetophenones (IV) and ammonium acetate. [ABSTRACT FROM AUTHOR]

On refluxing nitroarenes with NaOH and PEG 400 in benzene varying yields of the corresponding azoxybenzenes are obtained. [ABSTRACT FROM AUTHOR]