Ease Of Recycling Research Articles

Ease of Recycling in Glendale, Salt Lake City, Utah: Dissecting Recycling Efforts by Household Size, Age, Income and Gender

This study investigates the perceived ease of recycling in Glendale, Salt Lake City, Utah, USA, by household size, age, income, and gender. While existing research has broadly explored how sociodemographic factors impact recycling, there is a lack of comprehensive studies analyzing these factors within specific local contexts. This study aims to identify specific barriers and motivators across different demographics to enhance local recycling efforts using Glendale as a case study. Data were collected through an online survey of 111 respondents and analyzed using both quantitative and qualitative methods. The survey included questions about the demographic information, perceptions of recycling ease, and barriers to recycling. The analysis revealed that one-person households and young adults (18–35) face constraints such as limited space for recyclables, a lack of access to recycling bins in rental units, or high costs. Older adults (56 years or older) are highly committed but may face physical challenges. Higher-income households report higher participation due to better access and awareness, whereas lower-income households encounter significant barriers such as limited facility access and insufficient information. Gender differences indicate that women are slightly more proactive and committed to recycling compared to men. Recommendations include expanding recycling facilities, targeted educational campaigns, and economic incentives to encourage lower-income households, males, younger, and older adults. Addressing these demographic-specific barriers can improve recycling rates and contribute to more sustainable communities. Future studies should include in-person surveys as one of the limitations of this study is that an online survey format may introduce biases and the exclusion of residents without internet access.

A hydrate-based post-combustion capture system integrated with cold energy: Thermodynamic analysis, process modeling and energy optimization

Carbon capture is a crucial part of global warming mitigation. Carbon capture via clathrate hydrate is an attractive approach due to its high capture capacity, high carbon dioxide purity, water-based benign process, ease of recycling, and robustness to contaminants. In this work, we propose a two-stage hydrate-based carbon dioxide separation system integrated with cold energy for carbon capture from flue gases. A thermodynamic cycle consisting of two sub-cycles was constructed to simulate the process. Operating conditions were optimized within the range of 274.15–282.15 K and 0.1–28.04 MPa, resulting in the lowest electricity consumption of 2.22 MJ/kg CO2 with 95.24 mol% CO2 purity and 65.97 % CO2 recovery. A higher CO2 recovery rate can be achieved by recycling the residual gas of Sub-cycle 2. Gas compression to the high operating pressure (16.01 MPa) is the major contributor to electricity consumption. By incorporating 100 % expansion work recovery from the high-pressure gases, the electricity consumption can be reduced to 0.43 MJ/kg CO2 (i.e., 0.119 kWh/kg CO2). A more realistic scenario assuming 80 % compression/pumping efficiency and 90 % expansion work recovery gives an electricity consumption of 1.16 MJ/kg CO2 (i.e., 0.322 kWh/kg CO2), representing an energy penalty of 33.1 % for a coal-fired power plant. Future direction for further improvement could be a paradigm shift to hydrate process with thermodynamic promoters, which can potentially reduce the operation pressure by over 90 % and thus cut down the energy consumption dramatically. This work established a framework to simulate the hydrate-based carbon capture process, evaluated its minimum energy consumption and examined how operating conditions affect the separation performance. The results could offer valuable guidelines for the design and optimization of real hydrate-based carbon capture systems.

Hybrid reinforced effect of long carbon fiber and short glass fiber on polycarbonate foams

AbstractBecause of advantages such as remarkable mechanical properties and the ease of recycling, fiber‐reinforced thermoplastic polymer composites have been increasing in importance in industrial, transport, and sporting potential extraordinary applications. To fabricate polycarbonate (PC) components with lightweight and high mechanical properties, short glass fiber (SGF), long carbon fiber (LCF) reinforcement, and foaming technology were used in this study. The effects of SGF, LCF, and SGF/LCF on the mechanical properties and foaming quality of PC samples were carefully investigated and compared. The results show that SGF has a better foaming nucleation effect than LCF, and the mechanical enhancement effect of LCF is more significant than that of SGF. The combination of SGF and LCF can effectively improve the cell quality of foam samples and significantly enhance their mechanical properties. Therefore, a comprehensive application of the fiber‐reinforcement effect of PC resin is proposed.Highlights LCF and SGF reinforced PC foams have been successfully fabricated. Hybrid reinforced effect of LCF and SGF on PC foams was verified.

Experimental study and TiC interfacial action on microstructural and mechanical properties of AZ31 alloy composite made by stir casting route

The attention of magnesium alloy nanocomposite prepared with ceramic particle gathering is necessary for structural, marine, automobile, aviation, and defence applications because of its low density, high strength, castability, and ease of recycling. The different weight percentages (0, 2, 4, 6, and 8 wt%) of TiC nanoparticle reinforced magnesium alloy (AZ31) alloy synthesized by stir casting route and find the interface action on microstructural and mechanical characteristics of AZ31 alloy nanocomposites. The scanning electron microscopic images of the composite samples found uniform distributed TiC particles, and more than 6 wt% showed the agglomerated particle. The yield and tensile strength of composite (6 wt% TiC) was increased by 7.64% and 14.6% compared to the cast AZ31 alloy. The maximum hardness (112.5 ± 0.87Hv) was observed by AZ31/8 wt% composite. The tensile fracture of AZ31 alloy nanocomposite with 8 wt% was analyzed, and found poor interfacial action between the AZ31 and TiC. The higher content of TiC leads to brittle nature.

A comparative static and dynamic behavior of thermoplastic composite joints produced using different joining techniques

AbstractThermoplastic composites are preferred over their thermosetting counterparts due to their high toughness, fast manufacturing cycle, and ease of recycling. Another advantage is the variety of techniques available to join these thermoplastic composites. This paper analyzes the static and dynamic behavior of glass fiber‐reinforced thermoplastic composite joints produced using different joining techniques. The composite materials were fabricated by compression molding of glass fabric and polypropylene (PP) matrix. These composites were joined using approaches like riveting, adhesive bonding, resistance welding, and hybrid joining techniques. The performance of these joints was analyzed under static and dynamic tensile loads. During the static test, the resistance welded joints showed superior performance as compared to the other joining techniques. The highest load of 2183 N was taken by the resistance welded sample, while the least (358 N) was taken by the mechanical joint. In dynamic testing, the resistance welded joints showed the least variation in the modulus during the dynamic test, showing a higher modulus as compared to the other joining techniques. The highest number of cycles to fail the joint was obtained for the mechanical joint, that is, 40,100, while a similar value was exhibited by the resistance welded joint (39,674). The static and dynamic test results showed resistance welding to be a promising approach for joining thermoplastic composites.

Soda pulping of sunn hemp (Crotalaria juncea L.) and its usage in molded pulp packaging

Petroleum-based materials are often used in the packaging industry. However, the single use value of such products can be problematic with regard to proper waste disposal. As such, molded pulp packaging can be used as an alternative, given its ease of recycling, composting, and eventual biodegradation. In this work, we aims to study the pulp properties of sunn hemp and its usage as molded pulp products. For this purpose, unbleached beaten and unbeaten soda pulps derived from the whole stem of sunn hemp were examined for their fiber morphology, fibrillation, fiber classification, and physical properties. The sunn hemp pulp was subsequently molded using a batch molding machine. To determine the hydrophobicity of the molded pulp products, the molded samples were manufactured with and without additives. Finally, some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products. It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products. In terms of general usage, the molded products from sunn hemp pulp with additives were found to be capable of storing hot water, hot cooking oil, as well as microwaving water. We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.

A high-capacity Sn metal anode for aqueous acidic batteries

•Sn metal with high capacity and low potential as qualified anode for acidic battery •“Dead Sn” issue during Sn anode cycling has been identified and solved •Interfacial alloying regulation improves deposition uniformity and reversibility •Sn anode can be matched with various cathodes and delivers good performances Aqueous acidic batteries are a good choice to respond to battery diversity, delivering safety, cost, environmental friendliness, and high-power necessary for renewable energy storage. However, the practical adoption is greatly challenged by low voltage and energy density due to the inadequate metal anode materials. Here, we report an interfacial regulated Sn metal anode as the solution of the last piece of the puzzle. The ease of recycling, low potential, fast redox kinetics, and high capacity of Sn perfectly fit the battery system, and the Sn metal shedding critical issue is successfully suppressed by promoting uniform deposition for added interaction from alloying. Consequently, this reversible Sn anode with 442 mAh g−1 matches well to different types of cathodes. The as-assembled acidic batteries also demonstrate sufficient output voltage (up to 1.7 V), energy density (up to 312 Wh kg−1 based on both electrodes), kinetics (up to 24 C), and stability (up to 2,400 cycles). Aqueous acidic batteries are a good choice to respond to battery diversity, delivering safety, cost, environmental friendliness, and high-power necessary for renewable energy storage. However, the practical adoption is greatly challenged by low voltage and energy density due to the inadequate metal anode materials. Here, we report an interfacial regulated Sn metal anode as the solution of the last piece of the puzzle. The ease of recycling, low potential, fast redox kinetics, and high capacity of Sn perfectly fit the battery system, and the Sn metal shedding critical issue is successfully suppressed by promoting uniform deposition for added interaction from alloying. Consequently, this reversible Sn anode with 442 mAh g−1 matches well to different types of cathodes. The as-assembled acidic batteries also demonstrate sufficient output voltage (up to 1.7 V), energy density (up to 312 Wh kg−1 based on both electrodes), kinetics (up to 24 C), and stability (up to 2,400 cycles).

Luminescent converters based on nanocellulose + K3Tb(PO4)2:Eu composite films

The advantages of cellulose and its derivatives as the latest materials for devices that generate, store, and convert electricity are their low cost, environmental friendliness, ease of recycling and the ability to be manufactured in various ways and from various raw materials, including agricultural waste. This predetermines the relevance of their study as materials for modern technology and electronics. The research aims to determine the luminescent characteristics of composite films made based on nanocellulose and polycrystalline oxide K3Tb0.9Eu0.1(PO4)2. Optical microscopy and the spectral-luminescence method were used to characterise the films and their initial components. It was found that crystallites with an average size of about 50mm are distributed quite evenly in the film “nanocellulose+K3Tb0.9Eu0.1(PO4)2”. A Raman scattering band with a maximum of 564 nm under laser excitation at 473 nm was observed for the investigated samples in the form of suspensions. The intensity of photoluminescence of nanocellulose in suspension and films is low compared to the luminescence of oxide as a filler. The luminescence of Eu3+ ions is intense in the red region of the spectrum. The calculated values of the degree of asymmetry indicate low symmetry of the positions occupied by europium ions in the oxide and the contribution of Tb3+ ion emission to the overall spectrum of the composite film. The study results show that the luminescence of Eu3+ ions is sensitised by Tb3+ ions, which absorb the excitation light and then transfer energy to europium ions. The position of the absorption bands of Eu3+ and Tb3+ ions in the ultraviolet region of the spectrum and the intense emission of Eu3+ in the red region indicates the prospects of using nanocellulose+ K3Tb0.9Eu0.1(PO4)2 films to improve the efficiency of solar panels. Testing of the films under the excitation of luminescence by ultraviolet radiation of an LED (λex=375 nm) showed the possibility of developing white LEDs on their basis. In particular, the chromaticity coordinates of the uncoated LED were (x=0.214; y=0.079), and the use of a film composite as a coating causes a shift in the coordinates to the red region: x=0.304, y=0.196. The obtained results on the morphology and luminescent properties can be used to optimise the composition and manufacturing conditions of composite films of the following types “nanocellulose+K3Tb0.9Eu0.1(PO4)2” for use as fluorescent converters in LEDs or solar panels

Sodium Alginate–Aldehyde Cellulose Nanocrystal Composite Hydrogel for Doxycycline and Other Tetracycline Removal

A novel composite hydrogel bead composed of sodium alginate (SA) and aldehyde cellulose nanocrystal (DCNC) was developed for antibiotic remediation through a one-step cross-linking process in a calcium chloride bath. Structural and physical properties of the hydrogel bead, with varying composition ratios, were analyzed using techniques such as BET analysis, SEM imaging, tensile testing, and rheology measurement. The optimal composition ratio was found to be 40% (SA) and 60% (DCNC) by weight. The performance of the SA-DCNC hydrogel bead for antibiotic remediation was evaluated using doxycycline (DOXY) and three other tetracyclines in both single- and multidrug systems, yielding a maximum adsorption capacity of 421.5 mg g-1 at pH 7 and 649.9 mg g-1 at pH 11 for DOXY. The adsorption mechanisms were investigated through adsorption studies focusing on the effects of contact time, pH, concentration, and competitive contaminants, along with X-ray photoelectron spectroscopy analysis of samples. The adsorption of DOXY was confirmed to be the synergetic effects of chemical reaction, electrostatic interaction, hydrogen bonding, and pore diffusion/surface deposition. The SA-DCNC composite hydrogel demonstrated high reusability, with more than 80% of its adsorption efficiency remaining after five cycles of the adsorption-desorption test. The SA-DCNC composite hydrogel bead could be a promising biomaterial for future antibiotic remediation applications in both pilot and industrial scales because of its high adsorption efficiency and ease of recycling.

Research on Novel Heavy Metal Wastewater Treatment Methods

Heavy metals are frequently present in industrial effluent, and their excess can be detrimental to human health. Therefore, industrial wastewater needs to be treated before it can be discharged. Key solutions for the treatment of heavy metal wastewater are analyzed and evaluated based on existing research, taking into account elements like removal effectiveness, cost, ease of recycling, and number of reuses. This paper introduces two conventional and three novel heavy metal removal technologies are presented. The fundamental ideas, ideal circumstances, benefits, and drawbacks of each technology are summarized, along with a prediction of future technical developments. Although nanosorbents and microbial fuel cells are very efficient, their expenses are expensive. Membrane technology has a wide range of potential applications and is a great choice for the removal of heavy metals when combined with other technologies. Future wastewater treatment for heavy metals has a bright future thanks to all of these technologies.

Synthesis and Catalytic Application of MTsCOO‐Cu as a Melamine‐Based Metal‐Organic Framework in Facile Preparation of the 5‐Substituted‐1H‐Tetrazoles

AbstractA novel melamine‐based metal‐organic framework (MTsCOO‐Cu) has been designed, synthesized, and structurally characterized by FT‐IR, NMR, PXRD, FE‐SEM, EDX mapping, DTA, and TGA techniques. The MTsCOO‐Cu is successfully synthesized by the reaction of melamine with tosyl chloride and oxidation of methyl groups of the tosyl counterpart to carboxylic acids moieties and a consequent reaction with copper ion under ultrasonic irradiation. The synthesized MTsCOO‐Cu is catalytically used for the facile preparation of a series of 5‐substituted‐1H‐tetrazoles derivatives via click [3+2] cycloaddition reactions between various arrays of aromatic and aliphatic nitriles and sodium azide in PEG‐400 at 75 °C up to 86 %. The crucial reaction parameters including the type of solvent, temperature, and catalyst loading in progressing the reaction are evaluated and discussed. The synthesized MTsCOO‐Cu MOF showed an excellent catalytic activity, high chemical and thermal stabilities above 600 °C, simple preparation with readily available starting materials, and also ease of recyclability and reusability for four consecutive uses without considerable loss of activity. The output of this work may open new approaches for using new generations of MOFs catalysts in diverse chemical transformations.

Infusible thermoplastic resin based sandwich structures for wind blade applications and the influence of scrim on facesheet to core interface debonding

Infusible thermoplastic Elium® family of resins from Arkema have garnered much attention in recent years as a possible replacement for thermoset resins in laminate and sandwich composite manufacturing for wind blade applications due to its ease of recyclability and the ability to utilize existing manufacturing processes without imposing complicated variations. However, physical and mechanical properties of the proposed Elium® based thermoplastic composites must be comparable to existing epoxy (thermoset) based composites using manufacturing processes relevant for large wind turbine blades. A 13-meter-long demonstration blade was manufactured for that purpose and sandwich samples were obtained from that project for a detailed study. This paper details three-point flexural properties of unidirectional E-glass fiber reinforced acrylic and epoxy based sandwich panels with identical balsa wood core materials. In addition, to evaluate the relative merit considering debond failure mode, the interfacial critical strain energy release rate, predominantly in mode-1, was compared via single cantilever beam testing. In sandwich composites constructed with balsa wood core material, resin uptake by the balsa core is traditionally impeded via the insertion of a scrim material at the facesheet to core interface. Results revealed that inclusion of scrim mesh layer at the facesheet to core interface reduced flexural properties and strain energy release rates in panels infused with acrylic resin but did not significantly reduce these properties in epoxy infused facesheets.

Advances in Microfluidic Synthesis of Solid Catalysts

Heterogeneous catalysis plays a central role in the chemical and energy fields, owing to the high and tunable activities of solid catalysts that are essential to achieve the favorable reaction process efficiency, and their ease of recycle and reuse. Numerous research efforts have been focused on the synthesis of solid catalysts towards obtaining the desired structure, property and catalytic performance. The emergence and development of microfluidic reactor technology provide a new and attractive platform for the controllable synthesis of solid catalysts, primarily because of its superior mixing performance and high heat/mass transfer efficiency. In this review, the recent research progress on the synthesis of solid catalysts based on microfluidic reactor technology is summarized. The first section deals with the synthesis strategies for solid catalysts, including conventional methods in batch reactors and microfluidic alternatives (based on single- and two-phase flow processing). Then, different kinds of solid catalysts synthesized in microflow are discussed, especially with regard to the catalyst type, synthetic process, structure and property, and catalytic performance. Finally, challenges in the microreactor operation and scale-up, as well as future perspectives in terms of the synthesis of more types of catalysts, catalyst performance improvement, and the combination of catalyst synthesis process and catalytic reaction in microreactors, are provided.

Advances in Enzyme Induced Carbonate Precipitation and Application to Soil Improvement: A Review

Climate change and global warming have prompted a notable shift towards sustainable geotechnics and construction materials within the geotechnical engineer’s community. Earthen construction materials, in particular, are considered sustainable due to their inherent characteristics of having low embodied and operational energies, fire resistance, and ease of recyclability. Despite these attributes, they have not been part of the mainstream construction due to their susceptibility to water-induced deterioration. Conventional soil improvement techniques are generally expensive, energy-intensive, and environmentally harmful. Recently, biostabilization has emerged as a sustainable alternative that can overcome some of the limitations of existing soil improvement methods. Enzyme-induced carbonate precipitation (EICP) is a particularly promising technique due to its ease of application and compatibility with different soil types. EICP exploits the urease enzyme as a catalyst to promote the hydrolysis of urea inside the pore water, which, in the presence of calcium ions, results in the precipitation of calcium carbonate. The purpose of this paper is to provide a state-of-the-art review of EICP stabilization, highlighting the potential application of this technique to field problems and identifying current research gaps. The paper discusses recent progress, focusing on the most important factors that govern the efficiency of the chemical reactions and the precipitation of a spatially homogenous carbonate phase. The paper also discusses other aspects of EICP stabilization, including the degree of ground improvement, the prediction of the pore structure of the treated soil by numerical simulations, and the remediation of potentially toxic EICP by-products.

Three-dimensional macroscopic aminosilylated nanocellulose aerogels as sustainable bio-adsorbents for the effective removal of heavy metal ions

Designing an environmentally benign bio-adsorbent for the removal of heavy metal ions from aqueous medium was a sustainable strategy to ensure water safety. Herein, three-dimensional macroscopic aminosilyated nanocellulose aerogels (APTMS-modified TO-NFC) for the removal of heavy metal ions in water were successfully synthesized from bamboo-derived TEMPO-oxidized nanofibrillated cellulose (TO-NFC) and aminopropyltrimethoxysilane (APTMs) via a facile freeze-drying process. Owing to a relatively high BET surface area (129.32 m2 g−1), high porosity (99.14%) as well as high substitution degree of amino groups (0.41), the resulting APTMS-modified TO-NFC aerogel exhibited good adsorption capacity of 99.0, 124.5, and 242.1 mg g−1 for Cu2+, Cd2+ and Hg2+, respectively. Furthermore, the crosslinked and three-dimensionally porous architecture imparted it with relatively high compression strength, good excellent stability in water, and ease of recyclability from water after the usage. The pH value of the solution had a great influence on adsorption efficiency of the aerogel adsorbent, and optimal adsorption efficiency could be achieved at pH 3–7. Thermodynamic parameters suggested the spontaneous and endothermic nature of adsorption process. This work provides a facile method for preparing sustainable bio-adsorbent for effective heavy metal ions removal from aqueous medium.

Effects of Aging and Infill Pattern on Mechanical Properties of Hemp Reinforced PLA Composite Produced by Fused Filament Fabrication (FFF)

Reinforcing natural fibers to polymer matrices provides an increase in mechanical properties. In addition, bio composite materials contribute to the sustainable ecosystem with its ease of recyclability. The effect of accelerated aging on the mechanical properties of PLA matrix bio composite specimens has been observed in previous research, but the effect of accelerated aging on the mechanical properties and the resulting mass loss of the material produced with fused filament fabrication (FFF) has been discussed for the first time in this study. Aging was applied to the bio composite consisted of 10% hemp and PLA matrix produced at a constant rate, parallel to the tensile direction and cross (+/– 45°) angle, and the results were examined as tensile stress and mass loss. The aging effect has been observed even from the first week. Specimens with parallel printing to tensile direction showed a lower tensile performance than cross printing one, since the structure in the laminates is quite durable, the adhesion performance in the laminate or through thickness direction has been low. Natural fibers are found so highly hygroscopic that chemical treatments will improve the interface and increase the mechanical properties.

Validation of a lightning protection system for a fusion-welded thermoplastic composite wind turbine blade tip

Fusion welding for thermoplastic composite wind turbine blades is being investigated as a replacement for adhesives in bond lines to reduce manufacturing time and cost and to promote ease of recyclability. Resistance welding uses an electrically conductive material, such as carbon fiber, embedded in the bond line to heat the joining surfaces and fuse them together under pressure. One main challenge with fusion joining for large wind blades is the ability to use this conductive heating element in the bond line while still protecting the blade from the catastrophic effects of a lightning strike. This paper outlines the design and manufacturing of a lightning protection system for a 5-m-long thermally welded blade tip. The outcomes of high voltage and high current lightning testing applied to the 5 m blade tip show that the proposed design was able to protect the fusion welded bond lines from significant lightning damage.

Effects of natural hard shell particles on physical, chemical, mechanical and thermal properties of composites

Shelled herbal foods are widely consumed. The evaluation of the shells of these foods is important due to their features such as low cost, ease of recycling and environmental friendliness. In this study, hazelnut shell (HS), pistachio shell (PS), and apricot kernel shell (AKS) were brought to powder particles by grinding to dimensions of 300–425 µm. Some of the powder particles were converted into ash at 900°C. The amounts of cellulose, ash, humidity, and metal in these particles via chemical analyses were determined, while their structural properties via X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analyses. Composite materials were produced by adding 15 wt.% to the polyester matrix material from these powder particles and ashes. Compression strength, hardness, specific weight, and thermal conductivity of these composites were analyzed. The lowest and highest humidity, ash, cellulose, hemicellulose, and lignin ratios in powders showed differences depending on the type of powders. The amount of Sn and K in the HS, PS, and AKS powders were close to each other, while the amount of Ca, Na, Mg, Fe, Mn, Cu, Zn and Si was higher in AKS powder. The reinforcement adding to the polyester increased the compression strength, hardness, specific weight and thermal conductivity properties.

Exploring Aluminum‐Ion Insertion into Magnesium‐Doped Manjiroite (MnO2) Nanorods in Aqueous Solution

AbstractAqueous aluminum‐ion batteries are promising for sustainable energy storage given the abundance of aluminum and the ease of recycling. However, finding suitable electrode materials that can intercalate Al ions remains challenging. Here, we investigate Mg‐ion‐doped MnO2 nanorods in the manjiroite structure that allow Al‐ion insertion into the open tunnels of this material. The electrode material is characterized before and after Al‐ion insertion with X‐ray diffraction and X‐ray photoelectron spectroscopy, and the insertion process is studied via in situ transmission electron microscopy, which highlights a change in the length of the MnO2 nanorod. The results indicate that Al ions can be successfully inserted into the MnO2 nanorods, which has also been determined by density functional theory calculations to be an energetically favorable process. The electrochemical data indicate that diffusion‐controlled Al insertion as well as a surface pseudocapacitive effect occur. This indicates that MnO2 nanomaterials synthesized in the presence of metal cations is potentially a viable route for facilitating their use as electrode materials in aqueous Al‐ion batteries or supercapatteries.

(Invited) Recovering from Precipitation Events in Redox Flow Batteries

Liquid electrolyte solutions containing dissolved active material imbue Redox Flow Batteries (RFBs) with many unique benefits relative to solid-state electrochemical energy storage devices: long shelf-life, long system life-time, de-coupled rated energy and power, ease of recyclability.1 Operating a RFB system with flowing electrolyte solutions presents unique concerns as well, with one notable concern arising from possible precipitation of electrolyte. Precipitation of active material can have many consequences including sensor inaccuracy, inaccessible storage capacity, partially- or fully-blocked reactor electrode regions, and system clogging.Aqueous vanadium RFBs, a leading chemistry in commercial systems, has a precipitation mechanism at high temperatures for battery solutions containing commercially relevant vanadium concentrations >1.5 M. At elevated temperatures (> 40°C), positive electrolyte solutions can precipitate V2O5 dimers, first as a gel-like substance and eventually as solid particles.2 The Raytheon Technologies Research Center team has developed recovery procedures for systems that may succumb to such precipitation events; in the case for aqueous vanadium RFBs, exposure of precipitate to lower oxidation state forms of vanadium (i.e. negative electrolyte) reduces and redissolves precipitated V2O5. This electrolyte takeover process (ETP) can successfully redissolve precipitates and recover performance from precipitate-induced cell/stack under-performance.As Raytheon Technologies Research Center pursues alternative low-cost flow chemistries, the same ETP principles are applied to other chemistries such as polysulfide-based systems, known for sulfur crossover and precipitation of elemental sulfur in positive electrode volumes.3 This abstract will discuss the progress made at the Research Center to recover from precipitation events in such chemistries, which, unlike aqueous vanadium, do not permit simple mixing of negative and positive electrolytes. Acknowledgements: The authors gratefully acknowledge support from Vionx Energy Corporation. Some of the work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR000994. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.