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Mixed transition metal oxides with high theoretical capacity show great potential to replace carbonaceous anode materials in lithium-ion batteries.

Abstract The phase change of sodium acetate (SA) aqueous solution to sodium acetate trihydrate (SAT) requires large supercooling degree, then the aqueous solution can be at liquid state at fairly low temperature without releasing the stored latent heat. Such a feature makes SAT a promising material for seasonal solar thermal energy storage. The present study firstly summarized the thermo-physical properties of the solid SAT and liquid SA aqueous solution at different temperatures and concentrations, including equilibrium temperatures, densities, specific heats and thermal conductivities. The calculation methods of these properties have been established. Secondly, with the aid of the above properties, a mathematic model of the thermal discharge process of the storage system, i.e. the solidification process of supercooled SA aqueous solution, was built based on the heat transfer between the phase changing material within a single storage tube and the external flowing heat transfer fluid (HTF). The experimentally obtained SAT crystal growth rate and the enthalpy change of solidifying supercooled SA aqueous solution were employed to aid the modelling. The discharge temperature and thermal power of the storage system were numerically obtained and analysed. The influence of the ambient temperature, the mass flow rate as well as the heat transfer coefficient of the HTF on the thermal discharge performance were discussed. Finally, the seasonal thermal storage density of SAT was given and compared to that of water and some sorption materials.

Bioplastics are alternatives of conventional petroleum-based plastics. Bioplastics are polymers processed from renewable sources and are biodegradable. This study aims at conducting an environmental impact assessment of the bioprocessing of agricultural wastes into bioplastics compared to petro-plastics using an LCA approach. Bioplastics were produced from potato peels in laboratory. In a biochemical reaction under heating, starch was extracted from peels and glycerin, vinegar and water were added with a range of different ratios, which resulted in producing different samples of bio-based plastics. Nevertheless, the environmental impact of the bioplastics production process was evaluated and compared to petro-plastics. A life cycle analysis of bioplastics produced in laboratory and petro-plastics was conducted. The results are presented in the form of global warming potential, and other environmental impacts including acidification potential, eutrophication potential, freshwater ecotoxicity potential, human toxicity potential, and ozone layer depletion of producing bioplastics are compared to petro-plastics. The results show that the greenhouse gases (GHG) emissions, through the different experiments to produce bioplastics, range between 0.354 and 0.623 kg CO2 eq. per kg bioplastic compared to 2.37 kg CO2 eq. per kg polypropylene as a petro-plastic. The results also showed that there are no significant potential effects for the bioplastics produced from potato peels on different environmental impacts in comparison with poly-β-hydroxybutyric acid and polypropylene. Thus, the bioplastics produced from agricultural wastes can be manufactured in industrial scale to reduce the dependence on petroleum-based plastics. This in turn will mitigate GHG emissions and reduce the negative environmental impacts on climate change.

The catalytic active sites of NiFe and NiFeCr (oxy)hydroxides are revealed byoperandospectroscopic techonologies for alkaline water oxidation.

AbstractHigh‐performance dye‐sensitized solar cell (DSSC) devices rely on photoanodes that possess excellent light‐harvesting capabilities and high surface areas for sufficient dye adsorption. In this work, morphologically controlled SnO2 microstructures were synthesized and used as an efficient light‐backscattering layer on top of a nanocrystalline TiO2 layer to prepare a double‐layered photoanode. By optimizing the thickness of both the TiO2 bottom layer and the SnO2 top layer, a high power conversion efficiency (PCE) of 7.8 % was achieved, an enhancement of approximately 38 % in the efficiency compared with that of a nanocrystalline TiO2‐only photoanode (5.6 %). We attribute this efficiency improvement to the superior light‐backscattering capability of the SnO2 microstructures.

AbstractAlthough the road-map of the oxy-fuel process seems to be very advanced, there are still plenty of open questions. One of the significant ones is the corrosive behaviour of the heat exchanger surfaces. The Institute of Combustion and Power Plant Technology, University of Stuttgart, performs research on the fireside corrosion under oxy-fuel and conventional combustion conditions for the current and supercritical power plants considering the influence of combustion modus, gas atmosphere and fly ash deposits on the waterwall and superheater surfaces. Since the oxy-fuel-combustion atmosphere is composed of recirculated flue gases and pure oxygen, significantly higher concentrations of CO2, SO2 and H2O are present compared to the conventional combustion of coal with air as an oxidizer. In the here presented study the influence of an oxy-fuel combustion of a hard-coal on the surface of selected superheater materials is discussed and compared to the results obtained for lignite. Especially the interactions between the flue gas atmosphere, ash deposits and heat exchanger materials are studied in detail. The investigation encompassed in this paper has been focused on impacts of oxide-scale growth, carbon enrichment of the materials and sulphur-induced corrosion.Increased sulphur-induced corrosion has been observed in samples exposed to the oxy-combustion atmosphere. The noticed higher depth of corrosive attack of the oxy-fuel samples might be explained by a higher partial pressure of SO2 which is characteristic for oxy-fuel process. Moreover in certain cases the sulphur might be released by the deposits. Beside that, the oxy-fuel samples were exposed to much higher partial pressures of carbon dioxide comparing to the air-case leading apparently to rapid and massive internal carbon enrichment in the oxide scale. Moreover dependence between the chromium content and oxidation ability of the austenitic materials surfaces was noticed under oxy-fuel conditions.

Abstract Thermal energy storage with phase change materials (PCM) provides high storage capacities in small temperature intervals. For the design of storage systems, the enthalpy curve of the used PCM has to be known with high precision. The T-History method has evolved to a widely used method for the measurement of the enthalpy as a function of temperature of PCM because of its simplicity and the advantage to be able to investigate larger sample volumes than typically used for differential scanning calorimeters. In order to ensure isothermal specimen during the measurement a thermal insulation is often mounted around the sample holder, but this insulation material is not considered in the evaluation model. In this work a new evaluation model for insulated T-History setups is developed by an analytical heat balance. This model is validated by numerical simulations of insulated T-History measurements and experimentally. By the use of the new model for the evaluation of the enthalpy a significant increase of accuracy can be achieved.

Biomass is considered as a potential source of renewable energy. One of the major problems for biomass gasification is the presence of tar in the product gas. We are investigating catalytic behaviour of olivine as a prospective bed additive for biomass gasifiers for tar removal. In the present paper, the pretreatment of olivine is investigated to improve its activity. Pretreatment method includes heating olivine at 900 °C in the presence of air for different treatment times. The catalytic activity of olivine is investigated via steam-reforming reaction of naphthalene as model biomass tar compound. Improvement in naphthalene conversion of around 30% is observed with 1 h of pretreatment. Also effect of pretreatment time is investigated. With increasing pretreatment time, conversion increases; more than 80% naphthalene conversion is observed with 10 h of pretreatment time for olivine. Both steam and dry reforming reaction of naphthalene forms more than 50% gaseous products over 10 h pretreated olivine. Besides the gaseous products and light tars, polymerization reactions occur producing higher tars in small quantity. Naphthalene conversion under syngas mixture is somewhat lower than that of only in steam and CO2. Apparent activation energy of 187 kJ mol-1 is determined for 10 h pretreated olivine under gasification-gas mixture.

Energy Climate dataset consistent with ENTSO-E Pan-European Climatic Database (PECD 2021.3) in CSV and netCDF format TL;DR: this is a nationally aggregated hourly dataset for the capacity factors per unit installed capacity for storage hydropower plants and run-of-river hydropower plants in the European region. All the data is provided for 30 climatic years (1981-2010). Method Description The hydro inflow data is based on historical river runoff reanalysis data simulated by the E-HYPE model. E-HYPE is a pan-European model developed by The Swedish Meteorological and Hydrological Institute (SMHI), which describes hydrological processes including flow paths at the subbasin level. E-hype only provides the time series of daily river runoff entering the inlet of each European subbasin over 1981-2010. To match the operational resolution of the dispatch model, we linearly downscale these time series to hourly. By summing up runoff associated with the inlet subbasins of each country, we also obtain the country-level river runoff. The hydro inflow time series per country is defined as the normalized energy inflows (per unit installed capacity of hydropower) embodied in the country-level river runoff. A dispatch model can be used to decides whether the energy inflows are actually used for electricity generation, stored, or spilled (in case the storage reservoir is already full). Data coverage This dataset considers two types of hydropower plants, namely storage hydropower plant (STO) and run-of-river hydropower plant (ROR). Not all countries have both types of hydropower plants installed (see table). The countries and their acronyms for both technologies included in this dataset are: Country Run-of-River Storage Austria AT_ROR AT_STO Belgium BE_ROR BE_STO Bulgaria BG_ROR BG_STO Switzerland CH_ROR CH_STO Cyprus CZ_ROR CZ_STO Germany DE_ROR DE_STO Denmark DK_ROR Estonia EE_ROR Greece EL_ROR EL_STO Spain ES_ROR ES_STO Finland FI_ROR FI_STO France FR_ROR FR_STO Great Britain GB_ROR GB_STO Croatia HR_ROR HR_STO Hungary HU_ROR HU_STO Ireland IE_ROR IE_STO Italy IT_ROR IT_STO Luxembourg LU_ROR Latvia LV_ROR the Netherlands NL_ROR Norway NO_ROR NO_STO Poland PL_ROR PL_STO Portugal PT_ROR PT_STO Romania RO_ROR RO_STO Sweden SE_ROR SE_STO Slovenia SI_ROR SI_STO Slovakia SK_ROR SK_STO Data structure description The files is provided in CSV (.csv) format with a comma (,) as separator and double-quote mark (") as text indicator. The first row stores the column labels. The columns contain the following: first column (or A) contains the row number Label: unlabeled Contents: interger range [1,262968] second column (or B) contains the valid-time Label: T1h Contents represent time with text as [DD/MM/YYYY HH:MM]) column 3-52 (or C-AY) each contain the capacity factor for each valid combination of a country and hydropower plant type Label: XX_YYY the two letter country code (XX) and the hydropower plant type (YYY) acronym for storage hydropower plant (STO) and run-of-river hydropower plant (ROR) Contents represent the capacity factor as a floating value in the range [0,1], the decimal separator is a point (.). DISCLAIMER: the content of this dataset has been created with the greatest possible care. However, we invite to use the original data for critical applications and studies. The raw hydro data was generated as part of 'Evaluating sediment Delivery Impacts on Reservoirs in changing climaTe and society across scales and sectors (DIRT-X)', this project and therefor, Jing hu, received funding from the European Research Area Network (ERA-NET) under grant number 438.19.902. Laurens P. Stoop received funding from the Netherlands Organization for Scientific Research (NWO) under Grant No. 647.003.005.

Abstractπ‐Conjugated polyelectrolytes (CPEs) have been studied as interlayers on top of a separate hole transport layer (HTL) to improve the wetting, interfacial defect passivation, and crystal growth of perovskites. However, very few CPE‐based HTLs have been reported without rational molecular design as ideal HTLs for perovskite solar cells (PeSCs). In this study, the authors synthesize a triphenylamine‐based anionic CPE (TPAFS‐TMA) as an HTL for p‐i‐n‐type PeSCs. TPAFS‐TMA has appropriate frontier molecular orbital (FMO) levels similar to those of the commonly used poly(bis(4‐phenyl)‐2,4,6‐trimethylphenylamine) (PTAA) HTL. The ionic and semiconducting TPAFS‐TMA shows high compatibility, high transmittance, appropriate FMO energy levels for hole extraction and electron blocking, as well as defect passivating properties, which are confirmed using various optical and electrical analyses. Thus, the PeSC with the TPAFS‐TMA HTL exhibits the best power conversion efficiency (PCE) of 20.86%, which is better than that of the PTAA‐based device (PCE of 19.97%). In addition, it exhibits negligible device‐to‐device variations in its photovoltaic performance, contrary to the device with PTAA. Finally, a large‐area PeSC (1 cm2) and mini‐module (3 cm2), showing PCEs of 19.46% and 18.41%, respectively, are successfully fabricated. The newly synthesized TPAFS‐TMA may suggest its great potential as an HTL for large‐area PeSCs.