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The Arrhenius temperature integral is typically used in non-isothermal kinetic analysis, which is widely applied in gas–solid reactions in separation processes. In previous studies, researchers provided various methods to solve the temperature integral, but the error usually became significant when the value of x (x = Ea/RT) was too large or too small. In this paper, we present a new series method and design a computer program to calculate the temperature integral. According to the precise calculation of the temperature integral, we first reveal the relationship among the integral, the temperature, and the activation energy, and we find an interesting phenomenon in which the 3-D image of the temperature integral is of self-similarity according to fractal theory. The work is useful for mechanism and theoretical studies of non-isothermal kinetics.

Lithium-sulfur (Li-S) batteries with the merits of high theoretical capacity and high energy density have gained significant attention as the next-generation energy storage devices. Unfortunately, the main pressing issues of sluggish reaction kinetics and severe shuttling of polysulfides hampered their practical application. To overcome these obstacles, various strategies adopting high-efficient electrocatalysts have been explored to enable the rapid polysulfide conversions and thereby suppressing the polysulfide shuttling. This review first summarizes the recent progress on electrocatalysts involved in hosts, interlayers, and protective layers. Then, these electrocatalysts in Li-S batteries are analyzed by listing representative works, from the viewpoints of design concepts, engineering strategies, working principles, and electrochemical performance. Finally, the remaining issues/challenges and future perspectives facing electrocatalysts are given and discussed. This review may provide new guidance for the future construction of electrocatalysts and their further utilizations in high-performance Li-S batteries. [Figure not available: see fulltext.]. © 2022, Tsinghua University Press.

Abstract The aim of this study was to explore the utilization of Pennisetum sinese as cellulose source for the preparation of cellulose nanocrystals (CNC). The cellulose was extracted from P. sinese by chemical treatment and bleaching, and obtained cellulose nanocrystals by acid hydrolysis. Transmission electron microscopy (TEM) showed that CNC were rod-like with the diameter of 20–30 nm and the length of 200–300 nm. Fourier transform infrared (FTIR) showed that chemical treatment removed most of the lignin and hemicellulose from P. sinese , and CNC had similar structure to that of native cellulose. The crystallinity indexes calculated from X-ray diffraction (XRD) for P. sinese and CNC were 40.6% and 77.3%, respectively. The zeta-potential analysis showed that CNC had higher stability than P. sinese had. The thermal stability was investigated by thermogravimetric analysis (TGA), and the result showed that P. sinese had higher thermal stability than that of prepared CNC.

AbstractSolubilities of CO2, CH4, H2, CO and N2 in choline chloride/urea (ChCl/Urea) were investigated at temperatures ranging from 308.2 to 328.2 K and pressures ranging from 0.6 to 4.6 MPa. The results show that the solubilities of gases increase with increasing pressure and decreasing temperature. The solubility of CO2 is higher than that of CH4, H2, CO and N2, which indicates that ChCl/Urea may be used as a potential solvent for CO2 capture from the gas mixture. Solubility of CO2 in ChCl/Urea was fitted by Non-Random Two-Liquid and Redlich–Kwong (NRTL-RK) model, and solubility of CH4, H2, CO or N2 in ChCl/Urea was fitted by Henry's Law. The standard enthalpy, standard Gibbs energy and standard entropy of gases were calculated. Additionally, the CO2/CH4 selectivities in water, dry ChCl/Urea and aqueous ChCl/Urea were further discussed.

The inferior cycle lifespan and unsatisfactory energy density of traditional anode materials for sodium-ion batteries need to be improved toward actual application. Here, MOF-derived ultrafine ZnSe...

AbstractAlloy anodes composed of microsized particles receive increasing attention recently, which outperform the nanostructured counterparts in both the manufacturing cost and volumetric energy density. However, the pulverization of particles and fracture of solid electrolyte interphase (SEI) during cycling brings about fast capacity degradation. Herein, it is shown how normally considered fragile SEI can become highly elastic through electrolyte chemistry regulation. Compared to the SEI constructed in classic carbonate electrolyte, the atomic force microscopy tests reveal that the one built in ether‐based electrolyte doubles the maximum elastic strain to accommodate the repeated swelling‐contracting. Such an SEI effectively encapsulates the microsized Sb anodes to prevent the capacity loss from particle isolation. Coupled with an intercalation‐assisted alloying reaction mechanism, a sustained capacity of ≈573 mAh g−1 after 180 cycles at 0.1 A g−1 with outstanding initial Coulombic efficiency is obtained, which is among the highest values achieved in K‐ion batteries. This study emphasizes the significance of building robust SEI, which offers the opportunity to enable stable microsized alloy anodes.

Funding Information: This work was supported Southeast University (SEU) project 3203002003A1 and National Natural Science Foundation of China (NSFC) under the grant 51772080 and 11604088 . Jiangsu Provincial Innovation and Entrepreneurship Talent program Project No. JSSCRC2021491 . Industry-University-Research Cooperation Project of Jiangsu Province in China , Grant No. BY2021057 . Dr. Asghar thanks the Hubei Talent 100 program and Academy of Finland ( 13329016 , 13322738 ) for their financial support. Publisher Copyright: © 2022 The Authors Electrolytes with high-proton conduction and low activation energy are attractive for reducing the high operating temperature of solid-oxide fuel cells to less than <600 °C. In this work, we have fabricated semiconducting electrolyte SrFeTiO3-δ (SFT) material exhibiting high ionic conduction and exceptionally high protonic conduction at low operating temperature but with low electronic conduction to evade the short-circuiting issue. The prepared fuel cell device exhibited high open-circuit voltage (OCV) and a high-power output of 534 mW/cm2, of which 474 mW/cm2 could be for sure be related to the protonic part. The current study suggests that usage of semiconductor SrFeTiO3-δ facilitates a high concentration of oxygen vacancies on the surface of SFT, which mainly benefits proton conduction. Moreover, lower grain boundary resistance leads to obtain higher performance. Also, the Schottky junction phenomena are proposed to inhibit the e-conduction and excel the ions transportation. The high performance and ionic conductivity suggest that SFT could be a promising electrolyte for protonic ceramic fuel cells. Peer reviewed

Abstract This study presents a detailed kinetic investigation into ultra-rich oxidation of H 2 S-CH 4 under high temperature (900–1250 °C) and ambient pressure. Effects of temperature, initial H 2 S/CH 4 ratio and equivalence ratio (Φ) on reactants conversions and products distributions were experimentally studied in a tubular flow reactor and kinetically analyzed by CHEMKIN software. A detailed kinetic mechanism involving 85 species and 515 reactions has been developed and validated using reference data for H 2 S-CH 4 decomposition and results from extended experimental conditions involving the O 2 addition. For H 2 S-CH 4 system, conversion of H 2 S increased steady with the rising temperature while reactivity of CH 4 was weak at temperature below 1000 °C. At temperature higher than 1000 °C, conversion of CH 4 increased rapidly and devoted further formation of H 2 and CS 2 mainly via reacting with H 2 S decomposition products. The H 2 production efficiency was negatively associated with initial H 2 S fraction as H 2 S decomposition was dominant H 2 source within 1150 °C. The stoichiometric ratio for H 2 S/CH 4 merely showed its advantage in H 2 production at higher temperature under which CH 4 reached its equilibrium conversion swiftly. Introduction of little amount of O 2 (Φ = 6 or higher) accelerated the whole reaction process and triggered H 2 S partial oxidation and H 2 formation at lower temperature. CH 4 explicitly showed inferior position in oxidation competition with H 2 S and maintained poor conversion at temperature below 950 °C. The results of rate of production (ROP) analysis at condition without O 2 showed that CH 4 reactivity showed dependence on free S radical via S + CH 4 = SH + CH 3 , and the formed CH 3 was mainly converted via reacting with SH and H radicals. CH 3 could be concurrently reverted to CH 4 via reactions with H 2 S and H 2 . O 2 activated the whole system by forming chain branching radicals O and OH. These radicals promoted H 2 S and CH 4 conversions to form richer S, H and CH 3 radicals. SH + CS = CS 2 + H was important for CS 2 formation and with presence of O 2 , CS 2 was likely to be consumed via oxidation reactions. Finally reaction pathways for H 2 S, CH 4 conversion and H 2 , CS 2 formation were presented.