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Inorganic‐organic hybrid solid electrolytes (HSEs) are an important category of electrolyte materials for solid‐state batterie. It is of interest and importance to investigate the influence of composition and content of inorganic fillers on the electrochemical performance of HSEs. In this paper, we fabricated HSEs using polyethylene oxide (PEO) as matrix and incorporating different inorganic powders as active fillers. A series of HSEs with different contents of Ga/Nb co‐substituted garnet oxide (Li6.35Ga0.15La3Zr1.8Nb0.2O12, GN‐LLZO) and Y‐doped Li29Zr9Nb3O40 (Li29.3Zr8.7Y0.3Nb3O40, 0.3Y‐LZNO) were carefully designed. The ionic conductivity of these PEO‐based HSEs were studied, and their performance in solid‐state lithium‐ion batteries with LiFePO4 (LFP) as cathode material and Li metal as anode were evaluated. The results showed that the HSE with addition content of inorganic powders, namely PEOLiTFSI@5 % GN‐LLZO +5 %0.3Y‐LZNO (noted as PL3) showed the optimized ionic conductivity of 2.9×10−4 S cm−1 at room temperature with an activation energy Ea of 0.21 eV. It has an electrochemical stability window of 4.65 V and ionic transfer number of 0.242. The addition of inorganic powders not only enhanced the ionic conductivities of PEO‐based HSEs, but also exhibited superior stability and interfacial compatibility with electrodes, leading to the improved cycle stability in the LFP/PL3/Li solid‐state battery configuration. [ABSTRACT FROM AUTHOR]

Exploring efficient non-noble metal catalysts for the hydrogen evolution reaction (HER) will contribute to the development of clean and green energy technologies. Herein, we adopted a "waste utilization" strategy by using readily available and inexpensive coconut shell waste as a carbon source to synthesize carbon materials anchored with a Cu7Co alloy (Cu7Co/C) as a potential electrocatalyst for the hydrogen evolution reaction (HER). Utilizing a combination of hydrothermal and pyrolysis methods, the synthesized Cu7Co/C catalyst showcases superior HER electrocatalytic performance in alkaline solutions, with an overpotential of 134 mV at 10 mA cm−2 and a Tafel slope of 94 mV dec−1. The alloying of Cu and Co within Cu7Co/C markedly improves charge transfer capabilities, enhancing HER electrocatalysis. This research underscores the exceptional catalytic performance and stability of Cu7Co/C nanocomposites in alkaline media for the HER, attributed to a synergistic effect between the carbon derived from coconut shells and the bimetallic Cu7Co alloy. [ABSTRACT FROM AUTHOR]

To promote the safe use of MgO expansive agent (MEA) in mass concrete, the influence of fineness and sintering temperature of MEA on the expansion, mechanical properties, and microstructure of fly ash-Portland cement pastes was studied. The results indicate that the agent prepared at 950 °C does not adversely affect the compressive strength of the pastes. Whereas the agent prepared at 1150 °C (MII) has a marked negative impact on the volume stability and strength of the pastes. Furthermore, incorporating MII with coarser particle size results in a larger expansion, greater strength loss, and coarser pore structure. The presence of fly ash delays the hydration of MgO, making more MgO available for the formation of Mg(OH)2 at the late age. Meanwhile, the pozzolanic reaction leads to decreased total porosity, leaving less space available for the accommodation of Mg(OH)2. Consequently, fly ash cement pastes suffer greater strength loss than plain cement pastes when the destructive expansion occurs due to the delayed hydration of MgO. [ABSTRACT FROM AUTHOR]

Transition metal-based oxides have been reported as an important family of electrocatalysts for water splitting owing to their possible large-scale applications that are highly desirable for the hydrogen generation industry. Herein, we report a facile method for the preparation of phosphate-decorated NiFe oxides on nickel foam as efficient oxygen evolution reaction (OER) electrocatalysts for water oxidation. The OER electrocatalysts were developed through the pyrolysis of MIL(Fe) metal–organic frameworks (MOFs), which were modified with Ni and P species. It was found that the formation of NiO on the Fe2O3 surface (NiO@Fe2O3) can enrich electrocatalytic active sites for the OER. Meanwhile, the incorporation of P into NiO@Fe2O3 (Px-NiO@Fe2O3) creates abundant oxygen vacancies, which facilitates the surface charge transfer for OER electrocatalysis. Benefiting from the structure and composition advantages, P2.0-NiO@Fe2O3/NF exhibits the best performance for OER electrocatalysis among other prepared electrocatalysts, with an overpotential of 208 mV at the OER current density of 10 mA cm−2 and a small Tafel slope of 69.64 mV dec−1 in 1 M KOH solution. Additionally, P2.0-NiO@Fe2O3/NF shows an outstanding durability for the OER electrocatalysis, maintaining the OER current density above 20 mA cm−2 for more than 100 h. [ABSTRACT FROM AUTHOR]

Efficient and robust electrocatalysts towards the oxygen evolution reaction (OER) are highly desirable in electrochemical systems for applications including water splitting and metal-air batteries. Herein, we report the preparation of an amorphous FeCoNiMnCr high-entropy alloy (HEA) on the surface of flower-like 2H-MoS2 (FeCoNiMnCr@MoS2) as a highly efficient electrocatalyst for the OER. The flower-like 2H-MoS2 is prepared on the flexible conductive carbon cloth (MoS2-CC) via a hydrothermal method, and subsequently the amorphous FeCoNiMnCr HEA is loaded on the surface of 2H-MoS2via an electrodeposition method to form FeCoNiMnCr@MoS2-CC electrocatalysts. Owing to the unique microstructure of 2H-MoS2 and abundant active sites of FeCoNiMnCr HEA, the FeCoNiMnCr@MoS2-CC electrocatalysts exhibit significantly improved OER electrocatalytic performances with a low overpotential of 210 mV at a current density of 10 mA cm−2 and a small Tafel slope of 40.3 mV dec−1 in 1.0 M KOH solution. Moreover, it shows excellent stability for OER electrocatalysis with the potential barely increased for at least 50 h. This work sheds light on the development of highly efficient OER electrocatalysts based on HEAs. [ABSTRACT FROM AUTHOR]

Solid composite electrolytes exhibit tremendous potential for practical all-solid-state lithium metal batteries (ASSLMBs), whereas the interfacial contact between cathode and electrolyte remains a long-standing problem. Herein, we demonstrate an integrated design of a double-layer functional composite electrolyte and cathode (ID-FCC), which effectively improves interfacial contact and increases cycle stability. One composite electrolyte layer, PVDFLiFSI@LLZNTO (PL1@L), comes into contact with the LLZNTO (Li6.5La3Zr1.5Nb0.4Ta0.1O12)-containing cathode, while the other layer, PEOLiTFSI@LLZNTO (PL2@L) with a Li anode, is introduced in each. Such a design establishes a continuous network for the transport of Li+ on the interface, and includes the advantages of both PEO and PVDF for improving stability with the electrodes. The Li symmetric cells Li/PL2@L-PL1@L-PL2@L/Li steadily cycled for more than 3800 h under the current density of 0.05 mA cm−2 at 60 °C. Outstandingly, the all-solid-state batteries of LiFePO4-ID-FCC/Li showed an initial specific capacity of 161.5 mA h g−1 at 60 °C, demonstrating a remaining capacity ratio of 56.1% after 1000 cycles at 0.1 C and 74.5% after 400 cycles at 0.5 C, respectively. This work provides an effective strategy for solid-state electrolyte and interface design towards ASSLMBs with high electrochemical performance. [ABSTRACT FROM AUTHOR]

The widespread application of renewable energy technologies, such as electrochemical water splitting to produce H2 and rechargeable metal–air batteries, has called for the development of inexpensive and robust oxygen evolution reaction (OER) electrocatalysts. In this work, we report the synthesis of ultrafine Fe-doped Ni12P5 nanoparticles anchored on cotton-derived P-doped porous carbon ((FexNiy)12P5@PPC) by a facile impregnation-pyrolysis process. The results demonstrated that the Fe doping amount in Ni12P5 plays an important role in regulating the OER activity of electrocatalysts. As a result, the obtained (Fe0.25Ni0.75)12P5@PPC with a large surface area of 847.2 m2 g−1 and an average nanoparticle size of ∼8.5 nm exhibited superior OER activity, achieving extremely low overpotentials of 131 and 198 mV at 10 and 100 mA cm−2 in 1.0 M KOH electrolyte, respectively. The comprehensive investigations revealed that low-crystallized NiFe2O4 with high-spin Fe species in situ transformed from Fe-doped Ni12P5 during electrocatalysis is responsible for the high OER activity. The findings in this work would be helpful for rational design and development of inexpensive and robust OER electrocatalysts for applications in renewable energy technologies. [ABSTRACT FROM AUTHOR]

Electrosynthesis of NH3 through the N2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy‐ and capital‐intensive Haber–Bosch process. Herein, a room‐temperature spontaneous redox approach to fabricate a core–shell‐structured Au@CeO2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as‐synthesized Au@CeO2 possesses a surface area of 40.7 m2 g−1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH3 yield rate of 28.2 μg h−1 cm−2 (10.6 μg h−1 mg−1cat., 293.8 μg h−1 mg−1Au) and a faradaic efficiency of 9.50 % at −0.4 V versus a reversible hydrogen electrode in 0.01 m H2SO4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO2 nanoparticle shell of Au@CeO2; these are favorable for N2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO2, are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N2 into NH3. [ABSTRACT FROM AUTHOR]

Here, we report the synthesis of Cu-doped CeO2 nanorods (denoted as Cu-CeO2-x, x represents the mass content (wt%) of the doped Cu) by a facile hydrothermal method, followed by thermal treatment in an H2/Ar atmosphere. As the electrocatalyst, Cu-CeO2-3.9 with a large surface area of 95.2 m2 g−1 and mesoporous structure exhibits high electrocatalytic activity toward the N2 reduction reaction (NRR), delivering an NH3 yield rate of 5.3 × 10−10 mol s−1 cm−2 and a faradaic efficiency of 19.1% at −0.45 V (vs. RHE) in a 0.1 M Na2SO4 electrolyte (pH = 6.3), much higher than the NRR performance achieved with pure CeO2 nanorods. The Cu doping can effectively tune the concentration of multiple oxygen vacancies in CeO2, thus resulting in significantly improved NRR activity. [ABSTRACT FROM AUTHOR]