Sustainable Energy & Fuels最新文献

Cathodes of lithium-ion batteries (LIBs) significantly impact the environmental footprint, cost, and energy performance of the battery-pack. Hence, sustainable production of Li-ion battery cathodes is critically required for ensuring cost-effectiveness, environmental benignity, consumer friendliness, and social justice. Battery chemistry largely determines individual cell performance as well as the battery pack cost and life cycle greenhouse gas emission. Continuous manufacturing platforms improve production efficiency in terms of product yield, quality and cost. Spent-battery recycling ensures the circular economy of critical elements that are required for cathode production. Innovations in fast-charging LIBs are particularly promising for sustainable e-mobility with a reduced carbon footprint. This article provides an overview of these research directions, emphasizing strategies for low-cobalt cathode development, recycling processes, continuous production and improvement in fast-charging capability.

Thermogalvanic cells can potentially valorise the huge quantity of energy available as waste heat; using entropy-driven thermoelectrochemistry they can convert a thermal gradient into electricity. Most investigations exploit a thermal source (e.g. hot water, the human body, sunlight, electronics) via a heat exchanger (metal pipe, skin, housing, etc), combined with an unlimited heat sink (e.g. pumped cold water). Limited studies have used ambient air as the heat sink. This study is believed to be the first to explore using air as both the thermal source and heat sink. It compares thermogalvanic cell performance when using water–water and air–air as the thermal energy sources and sinks, respectively, for devices with relatively large physical dimensions (25 to 100 mm wide). Gelation improved power output under both scenarios, due to enhanced thermal isolation of the electrodes; power decreased with increasing width in the water–water setup, but power increased with increasing width for air–air harvesting. Water–water yielded higher power overall, yet the air–air system operated passively and could be further optimised for real-world applications, i.e. as thermogalvanic bricks or panels in building materials.

Covalent organic frameworks (COFs) enable highly effective photocatalysis due to their crystallinity, tunable pores and channels, and expansive light absorption. The performance of COFs in photocatalysis is underpinned by the intrinsic tendency of charge separation and transfer, thereby depending on the molecular building blocks. Benzobisthiazole (BBT), with an electron-withdrawing effect, shows superior potential in various optoelectronic materials. Therefore, with tetrabutylammonium hydroxide as a catalyst, a fully conjugated COF, BBT-sp²c-COF, is synthesized from 2,2′-(benzo[1,2-d:4,5-d′]bis(thiazole)-2,6-diyl)diacetonitrile and 1,3,6,8-tetrakis(4-formylphenyl)pyrene. As such, a series of characterizations demonstrate the structural and optical properties of BBT-sp²c-COF. The fully conjugated COF, BBT-sp²c-COF, possesses enhanced charge separation, electron transfer, and recycling stability. As expected, BBT-sp²c-COF photocatalysis achieves effective selective oxidation of benzyl amines with oxygen under blue light irradiation. Superoxide is identified as the crucial reactive oxygen species during the formation of imines. The full conjugation of organic building blocks into COFs can achieve highly effective photocatalysis.

Refused derived fuel (RDF) is finding suitable applications in thermochemical conversion methods, including plasma gasification, to generate clean syngas. This addresses both the challenges of sustainable energy and waste management. In this study, RDF waste is utilized in a plasma gasification unit integrated with combined cycle, molten carbonate fuel cell (IPGCC-MCFC) and chemical looping reforming (IPGCC-CLR) systems for the co-generation of hydrogen and electricity. The simulations of the proposed plants are conducted using Aspen Plus software, and subsequently, the techno-economic assessment and life cycle analysis are performed. The results indicated that the highest net overall energy efficiency of 66.05%, lowest cost of electricity of 74.90 $ per MW h and levelized cost of hydrogen of 1.02 $ per kg, can be obtained for the IPGCC-CLR system. This improved the energy return on investment to 2.89 MW/MW as compared to 1.69 MW/MW for the IPGCC-MCFC plant. The life cycle analysis estimated the total fossil fuel consumption of 5.06–6.16 MJ s⁻¹ and CO₂ emissions of 285.14–335.61 g_CO2eq. s⁻¹ throughout the project duration. The plants reduce fossil fuel consumption by 1.5 times and CO₂ emissions by 3 times as compared to the reported literature. Moreover, the analyses of other factors of environmental impact types of acidification potential, eutrophication potential, human toxicity potential, etc., show that the RDF processing stage contributes the largest pollution, followed by hydrogen compression and the transportation stage. The emissions can be minimized by replacing fossil fuels with hydrogen-based products at every stage.

Sodium acetate trihydrate (SAT) is an extremely potential low-temperature phase change material (PCM) in the solar power absorption, residual heat recovery, and other fields. Using coal gasification slag as a matrix for the sorption of SAT not only effectively solves the liquid leakage problem that occurs when the material is transferred from the solid phase to the liquid phase and but also improve the photothermal performance of the PCM, which is both environmentally friendly and economically valuable. A shape-stabilized coal gasification slag/sodium acetate trihydrate composite phase change material was therefore created in this work using the vacuum impregnation process, and its characteristics were examined. It was found that CGS is chemically compatible with SAT, and a CGS loading on SAT is 67.99%. on SAT results in a CPCM with better heat stability. Furthermore, the CPCM's latent heat could reach up to 171 J g⁻¹, and it exhibited excellent capability for solar thermal conversion, with an photothermal conversion efficiency of 77.8%.

For alkaline zinc secondary batteries, the hydrogen evolution corrosion and dendrite growth on the zinc anode result in its short cycle life and low capacity. Currently, the occurrence of side reactions is inhibited by anode alloyage, electrode or electrolyte additives, or altering the structural design of the electrode. Among them, altering the structural design can effectively enhance the cycling performance. Furthermore, the 3D interconnected network structure can realize a uniform electric field and ion distribution to improve the electrode reaction behavior. Inspired by this, a ZnO anode with a 3D cross-linked network structure was constructed using CNFs as the 3D skeleton. By regulating the ZnO content and the ratio of CNFs/CB in the ZnO@CNFs/CB materials, the effect of the component content on the performance of the ZnO anodes was analyzed. With the increase in ZnO contents and CNFs/CN ratios, the reversibility, hydrogenation inhibition effect, cycling performance and rate performance of the ZnO anodes first showed an increasing trend, followed by a decreasing trend. When the theoretical mass ratio (ZnO : CNFs : CB) between the components in the ZnO@CNFs/CB material was 8 : 1 : 1, it exhibited a high hydrogenation inhibition effect and reversibility. When the prepared materials were used as the ZnO anode material of the zinc–nickel battery, the specific discharge capacity after 600 cycles at 1C rate was 566.90 mA h g⁻¹, the coulombic efficiency was 86.02%, and the capacity retention rate was 90.17%. The average specific discharge capacity was 602.66 mA h g⁻¹.

This study presents the first application of metallic manganese as an anode in metal–air batteries, to the best of our knowledge, achieving an energy density of 1859 W h kg⁻¹ and a specific capacity of 1930 A h kg⁻¹ through galvanostatic discharge tests. This system delivers 2.5 times more energy per gram than zinc, a commonly used metal in metal–air batteries, under identical testing conditions. Electrochemical analysis and discharge by-product studies revealed a discharge process through three oxidation states of manganese: Mn, Mn(II), and Mn(III). The combined attributes of manganese, including its abundance and environmental stability, position the Mn–air battery as a viable and sustainable option for energy storage from intermittent renewable sources.

The catalytic properties of UiO-66 were enhanced through a post-synthetic defect engineering method. This involved facile treatment of the material with aqueous HCl to induce defects that generated free carboxylic acid (–COOH) groups. Consequently, the modified UiO-66 framework incorporated both Brønsted acidic –COOH groups and Lewis acidic sites, which originate from inherent linker-missing defects. These dual-functional acidic sites, combined with the high structural stability of UiO-66, enable it to act as an efficient heterogeneous catalyst for one-pot, multistep reactions. Specifically, the catalyst facilitates the conversion of glucose to levulinic acid (LEV) in the presence of sodium chloride (NaCl) as a promoter under hydrothermal conditions. Under optimized conditions (190 °C for 6 h), the catalytic system achieves a remarkable conversion of glucose (>99%), with an impressive 83% yield of LEV. The defect-engineered UiO-66 catalyst shows exceptional potential as a candidate for sugar conversion to valuable bio-based chemicals.

Photocatalytic CO₂ reduction over Ru(II)-complex/Ag/polymeric carbon nitride (PCN) was studied with respect to light intensity and the type of Ru(II) complex. In experiments using two different Ru(II) complex cocatalysts, the reduction potential of the Ru complex was found to balance efficient CO₂ reduction on the Ru complex with electron transfer from Ag/PCN. This balance avoided the formation of H₂ as a byproduct, minimized charge accumulation in Ag/PCN, and maximized the apparent quantum yield for CO₂-to-HCOOH conversion.

Carbides are commonly regarded as efficient hydrogen evolution reaction (HER) catalysts, but their poor oxygen evolution reaction (OER) catalytic activities seriously limit their practical application in overall water splitting. Herein, embedded nanosheets and plates of cobalt oxy carbide (Co–O–C/CPs) were successfully synthesized as an efficient bifunctional electrocatalyst using a solvent-free combustion process. To contribute to the clarification of catalytic particle composition during electrochemical reactions, we thoroughly characterized the Co–O–C/CPs using HR-TEM, which revealed that the filled nanoplates, with a cobalt oxide shell and cobalt carbide core, were wrapped with carbon. During electrochemical reactions, the filled nanoplates changed to an amorphous state owing to the decomposition of the crystalline material. After amorphization, the Co–O–C/CPs maintained the shape of the parent compound and exhibited a higher electrochemically active surface area (ECSA) and thereby demonstrated enhanced HER (115 mV) and OER (240 mV) performances at 10 mA cm⁻². When applying the Co–O–C/CPs as both the cathode and anode, a lower cell voltage of 1.60 V was required at 10 mA cm⁻² than that for the benchmark catalyst IrO₂/Pt/C/NF (1.63 V) with great stability in alkaline solution. This work provides a feasible strategy to fabricate cobalt oxy carbides and explores their possibility as bifunctional catalysts for water splitting.