Progress and prospects of pH-neutral aqueous organic redox flow batteries:Electrolytes and membranes

Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storage technology for the grid-scale integration of renewable electricity.pH-neutral AORFBs that feature high safety,low corrosivity,and environmental benignity are particularly promising,and their battery performance is significantly impacted by redox-active molecules and ion-exchange membranes(IEMs).Here,representative anolytes and catholytes engineered for use in pH-neutral AORFBs are outlined and summarized,as well as their side reactions that cause irreversible battery capacity fading.In addition,the recent achievements of IEMs for pH-neutral AORFBs are discussed,with a focus on the construction and tuning of ion transport channels.Finally,the critical challenges and potential research opportunities for developing practically relevant pH-neutral AORFBs are presented.

Implications of electrode modifications in aqueous organic redox flow batteries

Aqueous organic redox flow batteries(RFBs)exhibit favorable characteristics,such as tunability,multielectron transfer capability,and stability of the redox active molecules utilized as anolytes and catholytes,making them very viable contenders for large-scale grid storage applications.Considerable attention has been paid on the development of efficient redox-active molecules and their performance optimization through chemical substitutions at various places on the backbone as part of the pursuit for high-performance RFBs.Despite the fact that electrodes are vital to optimal performance,they have not garnered significant attention.Limited research has been conducted on the effects of electrode modifications to improve the performance of RFBs.The primary emphasis has been given on the impact of electrode engineering to augment the efficiency of aqueous organic RFBs.An overview of electron transfer at the electrode-electrolyte interface is provided.The implications of electrode modification on the performance of redox flow batteries,with a particular focus on the anodic and cathodic half-cells separately,are then discussed.In each section,significant discrepancies surrounding the effects of electrode engineering are thoroughly examined and discussed.Finally,we have presented a comprehensive assessment along with our perspectives on the future trajectory.

Paleoecology of Early Ordovician Reefs in the Yichang Area,Hubei:a Correlation of Organic Reefs Between Early Ordovician and Jurassic

The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs.

Study on Water-Soluble Organic Reducing Substances: II. Organic Reducing Substances Produced from Anaerobic Decomposition of Milk Vetch (Astragalus sinicus L.)

The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.

Effect of Ionic Liquids on Organic Reactions Based on Activity Coefficients at Infinite Dilution

It is important to know how ILs(ionic liquids)influence organic reaction.In this paper,activity coefficients at infinite dilution of more than 80 organic compounds in ILs are collected and analyzed systematically.Through the study on typical organic reactions happened in ILs,such as Diels-Alder,esterification and Friedel-Crafts reaction,the ratio of activity coefficients at infinite dilution of products and reactants is employed to estimate different effects of different structural ILs on the rate and selectivity of reactions.

Study on Water-Soluble Organic Reducing Substances. I. Determination of Organic Reducing Substances by Differential Pulse Voltammetry

A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the working conditions of differential pulse voltammetry (d.p. v.) for determining the organic reducing substances produced during the processes of the anaerobic decomposition of plant materials were established with a glass carbon electrode as working electrode, 1 M Ag-AgCl electrode with large area as reference electrode, 0.2 M NH4AC as supporting electrolyte and pH buffer solution, pulse amplitude (AE) of 25 mV, scan rate at 2 mV·S-1and scan potential ranging from -0.5 to +1.2 voltage(vs. M Ag-AgCl). The peak current proportional to the concentration of reducing substances, and the characteristic peak potential of each organic reducing substance were regarded as the quantitative and qualitative base, respectively. These results obtained under the conditions mentioned above directly reflect both the reducing intensity and capacity of the organic reducing system in soils.

Consideration and development of anaerobic fermentation equipment on solid organic rejectamenta

This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including： the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.

Research on Protective Renovation of Historic Blocks Based on Organic Renewal:A Case Study of South Section of Chuancheng Street,Handan City

Protection and renewal of historic blocks is not only protection of physical spaces,continuation of intangible cultures,but also management measures of the internal social affairs in the blocks.Taking Chuancheng Street Historic Block in Handan City for example,this paper investigated current situation of the block,applied the organic renewal theory in the block renovation,and put forward relevant space,population and management strategies,so as to provide references for the protective renovation of historic blocks.

Seismic response analysis of organic reef in gentle slope of rift basin

Analyzing the formation and sediment characteristics of gentle slope, the authors elaborate formation mechanism of organic reef and characteristics of reservoir in gentle slope of rift basin. Using the forward model of seismic exploration, the study provides the objective judgment for the exploration of organic reef reservoir in gentle slope of rift basin.

Benthic Bacteria Community Changes in Responses to Different Organic Resources from Macrophyte- and Algae-Dominated Areas of Lake Taihu, China

Carbon resources play an important role in affecting the benthic bacterial community in shallow lakes. In this study, pyrosequencing was applied to compare bacteria phylogenic profile in incubated sediments with normal and exchanged organic detritus in macrophyte-dominated East Lake Taihu and algal-dominated Meiliang Bay. We observed significant bacteria species variations in sediments from two bays, regardless of treatments. RDA (Redundancy Analysis) analysis showed that sediment characteristics, especially concentrations of total nitrogen might account for this differentiation. Besides, algal-dominated Meiliang Bay sediment with addition of Vallisneria detritus exhibited higher bacterial species variations than the sediment amended with Microcystis detritus. To the contrary, sediments from macrophyte-dominated East Lake Taihu shared similar bacteria profile at all taxonomic levels and grouped together in MDS (multidimensional scaling) plots over the treatments with Vallisneria or Microcystis detritus addition into the sediment. We speculated that the different degradability of macrophyte detritus and algal detritus led to varied bacterial responses to exchanged organic resources and ultimately, the amounts, nutrient availability and degradability of organic resources may be main reasons for benthic bacteria community structure differentiation between the two states in shallow lakes.

Recent progress in organic redox flow batteries:Active materials,electrolytes and membranes

Redox flow batteries （RFBs） have great potentials in the future applications of both large scale energy storage and powering the electrical vehicle. Critical challenges including low volumetric energy density. high cost and maintenance greatly impede the wide application of conventional RFBs based on inorganic materials. Redox-active organic molecules have shown promising prospect in the application of RFBs, benefited from their low cost, vast abundance, and high tunability of both potential and solubility. In this review, we discuss the advantages of redo~ active organic materials over their inorganic compart and the recent progress of organic based aqueous and non-aqueous RFBs. Design considerations in active materi- als, choice of electrolytes and membrane selection in both aqueous and non-aqueous RFBs are discussed. Finally. we discuss remaining critical challenges and suggest future directions for improving organic based RFBs.

Groups-dependent phosphines as the organic redox for point defects elimination in hybrid perovskite solar cells

Lead(Pb)^(0) and iodine(I)^(0) point defects generated during perovskite solar cell(PSC)fabrication and photoconversion form deep band energy levels as the carriers’recombination centers.These defects not only deteriorate device efficiency,but also facilitate chemical degradation with ion migration,resulting in restricted device lifetime.Herein,we present a novel type of phosphines as the point defects stabilizer for hybrid perovskite solar cells with enhanced performances.Three phosphines with varied side groups of tributyl,trioctyl and triphenyl are exampled as the dopants in perovskite films.The group dependent redox properties were observed in the perovskite film,dependent on their molecular weights and steric hinderances of phosphines.The partially oxidized tributyl phosphine(TBUP)with additional tributyl phosphine oxides(TBPO)is efficient in reduction of lead(Pb)^(0) and iodine(I)^(0) concentrations during the device fabrication and operation.The device with TBUP-TBPO pair showed enhanced power conversion efficiency(PCE)to 20.48% and maintain 91.7% of their initial PCEs after 500 h at 65℃ thermal annealing.Thus,this work presents an efficient route of utilize the phosphine species to reduce point defects in the perovskite film,which promoting further development of novel phosphorous additives with defects stabilization,interface passivation and encapsulation for low-cost solution processed PSCs.

A bipolar verdazyl radical for a symmetric all-organic redox flow-type battery

A symmetric all-organic non-aqueous redox flow-type battery was investigated employing the neutral small molecule radical 3-phenyl-1,5-di-p-tolylverdazyl,which can be reversibly oxidized and reduced in one-electron processes,as the sole charge storage material.Cyclic voltammetry of the verdazyl radical in 0.5 M tetrabutylammonium hexa fluoro phosphate(TBAPF6)in acetonitrile revealed redox couples at-0.17 V and-1.15 V vs.Ag+/Ag,leading to a theoretical cell voltage of 0.98 V.From the dependence of peak currents on the square root of the scan rate,diffusion coefficients on the order of 4 x 10 6 cm2 s-1 were demonstrated.Cycling performance was assessed in a static cell employing a Tokoyuma AHA anion exchange membrane,with 0.04 M verdazyl as catholyte and anolyte in 0.5 M TBAPF6 in acetonitrile at a current density of 0.12 mA cm-2.Although coulombic efficiencies were good(94%-97%)throughout the experiment,the capacity faded gradually from high initial values of 93%of the theoretical discharge capacity to 35%by the 50th cycle.Voltage and energy efficiencies were 68%and 65%,respectively.Postcycling analysis by cyclic voltammetry revealed that decomposition of the active material with cycling is a leading cause of cell degradation.

Prestack inversion identification of organic reef gas reservoirs of Permian Changxing Formation in Damaoping area, Sichuan Basin, SW China

Organic reef reservoirs in the platform margin of Kaijiang-Liangping trough in Damaoping area, Sichuan Basin are thin in single layer, fast in lateral variation, and have small P-impedance difference from the surrounding rock, it is difficult to identify and predict the reservoirs and fluid properties by conventional post-stack inversion. Through correlation analysis of core test data and logging P-S wave velocity, this work proposed a formula to calculate the shear wave velocity in different porosity ranges, and solved the issue that some wells in the study area have no S-wave data. AVO forward analysis reveals that formation porosity is the main factor affecting the variation of AVO type, the change of water saturation cannot affect the AVO type, but it has an effect on the change range of AVO. Through cross-plotting analysis of elastic parameters, it is found that fluid factor is a parameter sensitive to gas-bearing property of organic reef reservoir in the study area. By comparing results of post-stack impedance inversion, post-stack high frequency attenuation property, pre-stack simultaneous inversion and AVO anomaly analysis of angle gathers, it is found that the gas-bearing prediction of organic reef reservoirs by using fluid factor derived from simultaneous pre-stack inversion had the highest coincidence rate with actual drilling data. At last, according to the characteristics of fluid factor distribution, the favorable gas-bearing area of the organic reef reservoir in Changxing Formation was predicted, and the organic reef trap at the top of Changxing Formation in Block A of Damaoping area was sorted out as the next exploration target.

Organic Renewal of Sunken Yaodongs in Guanzhong: A Case Study of Dengjiapo Village in Yongshou County, Xianyang, Shaanxi

Sunken yaodongs, or sunken yaodong houses, in Guanzhong are typical representatives of traditional Chinese dwellings. This paper analyzed the characteristics and existing problems of yaodongs, and put forward the idea of the organic renewal of sunken yaodongs with Dengjiapo Village in Yongshou County, Xianyang, Shaanxi as the research object.

Carbonization of Chlorinated Organic Residual Liquid for Energy Source Generation

Chlorinated organic residual liquid is produced from the distillation process of new refrigerants production. It is difficult to be treated by traditional water treatment process and incineration process. In this study, a carbonization process at atmospheric pressure was used to convert this residual liquid to carbonaceous product and organic gas in 2 h at 230℃ or 260℃. The carbonaceous product was characterized by scanning electron microscope, Fourier-transform infrared spectrometer and thermo gravimetric analysis. The element composition and the high heat value of these products were similar to anthracite and lignite, respectively, showing that they could be used as alternative fuels. The components of organic gas were analyzed using gas chromatography-mass spectrometry and the gas had potential for incineration.

Biochemical Fractionation of Soil Organic Matter after Incorporation of Organic Residues

Soil organic matter (SOM) is a key factor for building and maintaining soil quality. The SOM quality is commonly assessed using densitometric and sieving separation methods, but such methods do not inform on the biochemical composition of SOM. Our objective was to evaluate the van Soest extraction procedure for soluble (SOL), holocellulose (HOLO) and lignin/cutin (LIC) fractions of SOM after incorporating crop residues and animal wastes into a C-depleted loamy sand. Millet cuttings, oat straw, fresh cattle manure and cattle manure compost were dried, sieved to obtain 53 - 250 and 250 - 2000 μm size fractions and characterized biochemically using a modified NDF-ADF-ADL van Soest method. Soil was also sieved into 53 - 250 and 250 - 2000 μm fractions. On a dry mass basis, crop residues contained 60% - 70% holocellulose while animal wastes contained more than 40% ash. Each soil fraction was combined with three rates of the corresponding organic fraction (2, 4, and 6 Mg&#183ha&#451 millet forage cuttings or oat straw and 5, 10, and 15 Mg&#183ha&#451 of cattle manure or cattle manure compost). Changes in soil biochemical components were analyzed using the balance method of compositional data analysis. Amendment, application rate and size fraction influenced significantly (p < 0.05) the [SOL | HOLO] balance but did not significantly affect the [SOL,HOLO | LIC] balance. The [SOL | HOLO] increased linearly with addition rate of crop residues, and decreased linearly with addition rate of animal wastes. This approach of balancing biochemical SOM components is a promising method to monitor the changes in SOM quality after the incorporation of organic residues and to elaborate beneficial practices for managing crop residues and animal wastes in agro-ecosystems.

Analysis of R134a Organic Regenerative Cycle

The analysis of organic regenerative cycles is necessary to verify the possibilities of increasing the work and efficiency of a thermodynamic cycle according to some control parameters. The results obtained from this work can be beneficial in several areas such as solar thermal energy. Simulations of an organic regenerative cycle with up to 4 extractions were carried out in order to analyze the behavior of maximum efficiency and the work generated in the turbine. R134a was used as an organic fluid, used in low temperature cycles. Evaporation temperature data between 60°C and 100°C and superheat temperatures equal to 120°C, 200°C and 300°C were tested for cycle analysis. Thus, it was possible to verify the work behavior and maximum efficiency depending on the number of extractions, superheating temperature and evaporation temperature. The models and simulations were made using the Engineering Equation Solver (EES) software and the results were analyzed in Excel. It was concluded that the maximum efficiency increases with the increase of the evaporation temperature and the number of extractions and decreases with the increase of the superheat temperature. The turbine work grows by increasing the evaporation and superheat temperatures, but decreases with the increase in extractions.

Molecular Structure Tailoring of Organic Spacers for High‑Performance Ruddlesden–Popper Perovskite Solar Cells

Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(PSC)technology.However,two-dimensional(2D)or quasi-2D RP PSCs are encountered with some challenges of the large exciton binding energy,blocked charge transport and poor film quality,which restrict their photovoltaic performance.Fortunately,these issues can be readily resolved by rationally designing spacer cations of RPPs.This review mainly focuses on how to design the molecular structures of organic spacers and aims to endow RPPs with outstanding photovoltaic applications.We firstly elucidated the important roles of organic spacers in impacting crystallization kinetics,charge transporting ability and stability of RPPs.Then we brought three aspects to attention for designing organic spacers.Finally,we presented the specific molecular structure design strategies for organic spacers of RPPs aiming to improve photovoltaic performance of RP PSCs.These proposed strategies in this review will provide new avenues to develop novel organic spacers for RPPs and advance the development of RPP photovoltaic technology for future applications.