PURIFICATION OF COBALT ANOLYTE USING THE NOVEL SOLVENT EXTRACTION SYSTEM

In present research, a novel extractant system (D2EHPA + naphthenic acid + pyridine- ester) was used to purify cobalt anolyte and a simulated industrial production were carried out. This novel extraction system can extract Cu and/or Ni against Co from chloride medium solutions at pH range of 2.5-4.5. About 2g/l nickel and 0.2g/l copper were removed from the cobalt chloride anolyte containing about 100g/l cobalt and 200g/l chloride ions respectively, the raffinate contains nickel and copper less than 0.03g/l and 0.0003g/l respectively and can be used to electrolyze high-purity cobalt. About 5.5t cobalt anolyte was purified in the simulation industrial experiment and kilogram quantities of cobalt of 99.98% purity and about 95% recovery have been produced.

Biphenyl-lithium-TEGDME solution as anolyte for high energy density non-aqueous redox flow lithium battery

Non-aqueous redox flow batteries, because of larger operating voltage, have attracted considerable at- tention for high-density energy storage applications. However, the study of the anolyte is rather limited compared with the catholyte due to the labile properties of redox mediators at low potentials. Here, we report a new strategy that exploits high concentration organic lithium metal solution as a robust and energetic anolyte. The solution formed by dissolving metallic lithium with biphenyl （BP） in tetraethylene glycol dimethyl ether （TEGDME） presents a redox potential of 0.39V versus Li/Li＋, and a concentration up to 2 M. When coupled with a redox-targeted LiFePO4 catholyte system, the constructed redox flow lithium battery full cell delivers a ceil voltage of 3.0V and presents reasonably good cycling performance.

Eu-based anolytes for high-voltage and long-lifetime aqueous flow batteries

Aqueous flow batteries(AFBs) are among the most promising electrochemical energy storage solutions for the massive-scale adoption of renewable electricity because of decoupled energy and power, design flexibility, improved safety and low cost. The development of high-voltage AFB is, however, limited by the lack of stable anolytes that have low redox potential. Here we report Eu-based anolytes for high-voltage p H-neutral AFB applications. Eu^(3+) has a reduction potential of -0.39 V vs. SHE, which can be dramatically lowered when forming stable complex with inexpensive organic chelates. A typical complex, Eu DTPA,features a low redox potential of -1.09 V vs. SHE, fast redox kinetics, and a high water solubility of 1.5 M. When paired with ferrocyanide, the battery had an open-circuit voltage of 1.56 V and demonstrated stable cell cycling performance, including a capacity retention rate of 99.997% per cycle over500 cycles at 40 m A cm^(-2), a current efficiency of >99.9%, and an energy efficiency of >83.3%. A high concentration anolyte at 1.5 M exhibited a volumetric capacity of 40.2 Ah L^(-1), which is one of the highest known for p H-neutral AFBs, promising a potent solution for the grid-scale storage of renewable electricity.

Comparison of Anolyte and Chlorine Dioxide for a Continuous Hot Water Disinfection in Nursing Home: A Two Years Legionnaires’ Disease Prevention

Worldwide epidemiological reports assert that drinking water is a source for infections and Legionella control represents a critical issue in healthcare settings. Chemical disinfections of water networks are control measures that need to be fine-tuned to obtain satisfactory results in large buildings over prolonged time periods. Aim of study is the evaluation of the effect of anolyte and chlorine dioxide, applied in two different hot water networks of a nursing home to manage Legionella risk. Nursing home has two buildings (A and B), with the same point of aqueduct water entrance. From June 2016, following a shock chlorination, the continuous disinfections with chlorine dioxide and anolyte were applied in hot networks of building A and B, respectively. Hot water was sampled at the central heating system and at two points of use for Legionella research, while chemical tests of manganese (Mn), iron (Fe), zinc (Zn) and trihalomethanes compounds (THM) were implemented to evaluate the disinfection by-products presence. Before chlorination Legionella pneumophila sg1 was recovered with a mean count of 2.4 × 104 CFU/L, while chemical compounds concentrations were within the law limits (Directive 98/83/EC). Then the disinfections Legionella was not recovered in both hot water plants. After the disinfection with chlorine dioxide (from June 2016 to May 2018), a statistically significant increase of iron, zinc and THM concentrations was detected in building A (p = 0.012;p = 0.004;p = 0.008). Both disinfectants appear effective against Legionella spp. growth in water network, but anolyte ensures a lower disinfection by-products release.

Arylene Diimide Derivatives as Anolyte Materials with Two-Electron Storage for Ultrastable Neutral Aqueous Organic Redox Flow Batteries

Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly limited by the structural instability of the highly reduced species.By combining the extendedπ-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species,we reported a series of highly conjugated and inexpensive arylene diimide derivatives(NDI,PDI,and TPDI)as novel two-electron storage anolyte materials for ultrastable AORFBs.Matched with(ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte,arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date.The NDI/FcNCl-based AORFB delivered 98.44%capacity retention at 40 mA cm^(−2)for 350 cycles;TPDI/FcNCl-based AORFB also showed remarkable stability with 97.22%capacity retention at 20 mA cm^(−2)over 200 cycles.This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.

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.

镍精矿除铜的单纯形优化

本文简要叙述了单纯形优化的基本思想与寻优步骤。应用单纯形法对镍精矿—阳极泥—镍电解阳极液反应体系的深度除铜条件进行了寻优试验,其结果与前人的试验及工业实践基本相同,表明单纯形优化方法是确定多变量湿法冶金体系中某些重要因素的一种快速而简单的方法。

Corrosion pathways in aluminium alloys

The corrosion pathways in AA2024-T3, AA5083-O and AA6082-T6 alloys have been investigated. The objective of the investigation is to further the understanding of the complex localised corrosion mechanism in aluminium alloys. The investigation was carried out by examining the corroded surfaces of the alloys after potentiodynamic polarization tests in a 3.5% NaCl solution with the aid of a scanning electron microscope, and by analysing the flow of anolyte solution using the scanning vibrating electrode technique. The results revealed that the overall corrosion pathways in the alloys are distinctively different and are influenced by the flow of anolyte solution. Also revealed, was the fact that corrosion propagates in two ways （particularly in the AA5083-O and AA6082-T6 alloys）： an overall pathway in the corrosion front （filiform-like pathway in the AA5083 alloy and organized linear pathways in AA6082 alloy）; and the crystallographic channelling along the （100） directions. These are dependent on the grain distinct features of the AA5083-O and AA6082-T6 alloys and are not influenced by the presence of coarse second phase particles in these alloys, compared with the AA2024-T3 alloy, where the corrosion pathways are more dependent on the presence of second phase particles and grain boundary character.

Aqueous decoupling batteries: Exploring the role offunctional ion-exchange membrane

The relentless pursuit of sustainable and safe energy storage technologies hasdriven a departure from conventional lithium-based batteries toward other relevantalternatives. Among these, aqueous batteries have emerged as a promisingcandidate due to their inherent properties of being cost-effective, safe,environmentally friendly, and scalable. However, traditional aqueous systemshave faced limitations stemming from water's narrow electrochemical stabilitywindow (-1.23 V), severely constraining their energy density and viability inhigh-demand applications. Recent advancements in decoupling aqueous batteriesoffer a novel solution to overcome this challenge by separating the anolyteand catholyte, thereby expanding the theoretical operational voltage windowto over 3 V. One key component of this innovative system is the ion-selectivemembrane (ISM), acting as a barrier to prevent undesired crossover betweenelectrolytes. This review provides a comprehensive overview of recent advancementsin decoupling aqueous batteries, emphasizing the application of varioustypes of ISMs. Moreover, we summarize different specially designed ISMs andtheir performance attributes. By addressing the current challenges ISMs face,the review outlines potential pathways for future enhancement and developmentof aqueous decoupling batteries.

Improved energy recovery from dark fermented cane molasses using microbial fuel cells

A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermen- tation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol Hz/kg CODremoved was observed in the batch process compared to 11.6 mol Hz/kg CODremoved in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect ofpre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m3 was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.