Sulfides are promising electrolyte materials for all-solid-state Li metal batteries due to their high ionic conductivity and machinability. However, compatibility issues at the negative ...electrode/sulfide electrolyte interface hinder their practical implementation. Despite previous studies have proposed considerable strategies to improve the negative electrode/sulfide electrolyte interfacial stability, industrial-scale engineering solutions remain elusive. Here, we introduce a scalable Li-Al-Cl stratified structure, formed through the strain-activated separating behavior of thermodynamically unfavorable Li/Li
Al
and Li/LiCl interfaces, to stabilize the negative electrode/sulfide electrolyte interface. In the Li-Al-Cl stratified structure, Li
Al
and LiCl are enriched at the surface to serve as a robust solid electrolyte interphase and are diluted in bulk by Li metal to construct a skeleton. Enabled by its unique structural characteristic, the Li-Al-Cl stratified structure significantly enhances the stability of negative electrode/sulfide electrolyte interface. This work reports a strain-activated phase separation phenomenon and proposes a practical pathway for negative electrode/sulfide electrolyte interface engineering.
Polyethylene oxide (PEO)-based solid electrolytes, which exhibit ideal extensibility and wide electrochemical window, are considered as one of the most promising candidates for all solid-state sodium ...batteries (ASSSBs). However, the low mechanical strength and low ionic conductivity hinder their application. Herein, electrospun MgAl
2
O
4
nanofibers are complexed with PEO/NaClO
4
to enhance the mechanical and thermal stability. Determined by
23
Na solid-state nuclear magnetic resonance spectroscopy combined with first-principle calculations, the adsorption energy of ClO
4
−
on the MgAl
2
O
4
surface is far higher than that on PEO, which facilitates the dissociation of Na
+
and ClO
4
−
, thereby enabling a fast transport of Na
+
by the introduction of MgAl
2
O
4
in the polymer electrolyte. The ionic conductivity is enhanced to 1.89 × 10
−4
S cm
−1
from 8.46 × 10
−5
S cm
−1
at 55 °C, and the Na
+
transfer number is improved to 0.55 from 0.26 in the composite electrolyte. The Na//(PEO/MgAl
2
O
4
/NaClO
4
)//Na symmetric cell can cycle for over 400 h at a current density of 0.05 mA cm
−2
and a cut-off capacity of 0.05 mAh cm
−2
while the ASSSBs incorporating the polymer composite electrolyte also exhibit notable rate and cycle performances.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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Urea oxidation reaction (UOR) has been widely considered as an alternative anodic reaction to water oxidation for the green production of hydrogen fuel. Due to the high catalytic ...activity of transition metal oxides towards UOR, various strategies have been developed to improve their syntheses and catalytic properties. However, little is known about the underlying mechanisms of UOR on catalyst surface. In this work, three transition metal oxides, including NiO, Co3O4, and Fe2O3 are investigated as model catalysts. Through analyzing the electrochemical properties by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and operando Raman spectroscopy, it is revealed that NiO has a unique high catalytic activity towards UOR due to simultaneous formation of a thin layer of oxyhydroxide species above 1.40 V vs. RHE in alkaline media. In addition, density functional theory (DFT) calculations further suggest that the adsorption of urea molecules is largely affected by surface interactions resulting in different space configurations, which impose large influences on the consecutive deprotonation and NN formation processes. Overall, results of this work point to the subtle adsorption − kinetics relationship in UOR and highlight the importance of the interfacial electronic interactions on catalyst surface.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Both developed and developing countries are producing a large amount of heavy metal solid waste, such as municipal sludge, waste incineration fly ash, tailings, metallurgical and chemical solid ...waste, and electronic waste. In the process of transferring and disposing these heavy metal-containing wastes, the exposure of heavy metals will cause a very serious impact on human health and the ecological environment. Due to the shortage of resources as well as the need of circular economy, there is an urgent need to recover materials from solid waste efficiently and economically by advanced treatment technology. Chlorination roasting technology is a smelting process that uses the principle of chlorination metallurgy to recover valuable metals from solid waste. It has the characteristics of strong applicability of raw materials, high separation efficiency and good comprehensive recovery effect. However, the application of chlorination roasting technology in heavy metal solid waste still lacks a comprehensive and systematic understanding, which hinders the promotion of this technology. This review summarizes the application status of chlorination roasting technology in the extraction of metals from four typical solid wastes, including tailings solid waste, electronic solid waste, municipal solid waste and industrial solid waste. We not only make in-depth analysis of the transformation process of metal elements (toxic metals, rare precious metals) in solid waste during the chlorination roasting process, but also summarize the proposed mechanisms of chlorination roasting. Finally, based on the comprehensive discussions above, we provide some the methods for enhancing the effect of chlorination roasting and design a much more efficient metal recovery process.
The scheme of extracting heavy metals from solid wastes by chlorination roasting method. Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Along with the emerging modern urea-based energy conversion technologies, electrocatalytic urea oxidation reaction (UOR) plays an important role in urea-rich wastewater treatment and hydrogen ...production. However, the sluggish kinetics of UOR which involves 6-electron transfer process has impeded its widespread applications. Hence, the development of efficient electro-catalysts is vital for the application of UOR and considerable progress has recently been reported. Among the various UOR catalysts, Ni-based catalysts have been widely studied due to their high UOR activity, abundant resources and long-term sustainability. Their high activity seems to be derived from the surface transformation behavior it undergoes during UOR. The surface transformation behavior results in some intermediates which are the real active sites in the reaction. Further investigation of the surface transformation behavior of Ni-based catalysts is critical and prerequisite for unraveling the underlying UOR mechanisms. Some advanced in situ characterization techniques should be combined during investigation. In this way, some effective methods for synthesis and modification of Ni-based catalysts can be proposed to boost UOR. In this review, we make a compressive summary of the widely accepted UOR mechanisms and the application of several key in situ characterization techniques in revealing surface transformation behavior and reaction mechanism of UOR. Recent advances of Ni-based electro-catalysts were discussed, especially in the methods of improving their UOR performance. We also propose some challenges and prospects for the future development of advanced characterization technologies and corresponding Ni-based catalysts in UOR.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Water electrolysis has become a promising green and sustainable strategy for hydrogen fuel production. However, due to the slow kinetics of the oxygen evolution reaction (OER), large overpotentials ...are required to drive the overall reaction. In this work, we demonstrate an environmentally friendly and energy-saving strategy by the synergy of the urea oxidation reaction (UOR) with the hydrogen evolution reaction (HER) to replace the ordinary water hydrolysis. In order to further boost the UOR kinetics, nickel borate (Ni-B
i
) is synthesized by a facile co-precipitation method, forming a nanosheet morphology and 3D hierarchical porous structure. The resulting Ni-B
i
catalyst exhibits exceptionally high catalytic performance for the UOR, achieving a current density of 50 mA cm
−2
at 1.42 V
vs.
RHE, which is about 250 mV lower than that of the OER process. The two-electrode urea electrolytic cell composed of the Ni-B
i
anode and a Pt cathode requires a small cell voltage of 1.66 V in order to reach a current density of 50 mA cm
−2
and is very stable. Overall, this work demonstrates a promising electrocatalyst system for efficient hydrogen production and simultaneous urea-containing wastewater treatment, providing valuable information for the development of advanced non-noble metal catalysts for the UOR.
Using Ni-B
i
as a UOR catalyst not only enables urea-wastewater decomposition but also promotes energy efficiency for hydrogen production.
