Solvent extraction and separation of cobalt from leachate of spent lithium-ion battery cathodes with N263 in nitrite media

To effectively separate and recover Co(Ⅱ) from the leachate of spent lithium-ion battery cathodes,we investigated solvent extraction with quaternary ammonium salt N263 in the sodium nitrite system.NO_(2)^(-)combines with Co(Ⅱ) to form an anion [Co(NO_(2))_(3)]^(-),and it is then extracted by N263.The extraction of Co(Ⅱ) is related to the concentration of NO_(2)^(-).The extraction efficiency of Co(Ⅱ) reaches the maximum of99.16%,while the extraction efficiencies of Ni(Ⅱ),Mn(Ⅱ),and Li(Ⅰ) are 9.27%-9.80% under the following conditions:30vol% of N263 and15vol% of iso-propyl alcohol in sulfonated kerosene,the volume ratio of the aqueous-to-organic phase is 2:1,the extraction time is 30 min,and1 M sodium nitrite in 0.1 MHNO_(3).The theoretical stages require for the Co(Ⅱ) extraction are performed in the McCabe–Thiele diagram,and the extraction efficiency of Co(Ⅱ) reaches more than 99.00% after three-stage counter-current extraction with Co(Ⅱ) concentration of 2544mg/L.When the HCl concentration is 1.5 M,the volume ratio of the aqueous-to-organic phase is 1:1,the back-extraction efficiency of Co(Ⅱ)achieves 91.41%.After five extraction and back-extraction cycles,the Co(Ⅱ) extraction efficiency can still reach 93.89%.The Co(Ⅱ) extraction efficiency in the actual leaching solution reaches 100%.

First-principles study on the co-adsorption of water and oxygen molecules on chalcopyrite(112)-M surface

Chalcopyrite is a common copper-bearing mineral with antiferromagnetic properties.However,this property has rarely been considered in previous studies for detailed adsorption behaviors of molecules on chalcopyrite.Based on density functional theory(DFT),new adsorption pathways by H_(2)O and O_(2)on the chalcopyrite metal terminated(112)surface((112)-M)is found in this work.First,through simulating the adsorption of an isolated water molecule and monolayer water molecules,it is confirmed that H_(2)O molecules tend to adsorb on the surface Fe atoms more than on the surface Cu atoms.Then,we studied various adsorption behaviors of the O_(2)molecule.It is found that the adsorption on the hollow FeAFe site is the most stable case;however,O_(2)is undissociated.Two adsorption cases will happen when H_(2)OAO_(2)adsorb simultaneously on the surface.For the S site,the H_(2)O molecule thoroughly dissociated and formed SAO species,and the other case is H_(2)O undissociated adsorbing at the Cu site.For the former case,it is interesting that H_(2)O is dissociated before O_(2).

Effect of content and spin state of iron on electronic properties and floatability of iron-bearing sphalerite:A DFT+U study

Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.

A functionalized activated carbon adsorbent prepared from waste amidoxime resin by modifying with H_(3)PO_(4) and ZnCl_(2) and its excellent Cr(Ⅵ)adsorption

With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.

Interface optimization and defects suppression via Na F introduction enable efficient flexible Sb_(2)Se_(3) thin-film solar cells

Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.

A review of flotation and selective separation of pyrrhotite:A perspective from crystal structures

Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic properties, and consequently different flotation behavior. In the present paper, a comprehensive review is conducted to discuss the influence of crystal structures on the natural floatability, mineral-reagent interaction, surface oxidation and flotation electrochemistry of pyrrhotite. The selective flotation process of pyrrhotite from its associated minerals is also reviewed in this paper. It is hoped that this review can summarize the newly published research results combined with some representative results from the past, to provide a theoretical basis for the study of the flotation mechanism of pyrrhotite and provide a new direction for future research on pyrrhotite.

Insights into the adsorption performance and mechanism of hydrated Ca ion on talc(001) basal surface from DFT calculation

The utilization of Ca ion as assistant depressant of CMC on talc has been widely reported.Thus,the study on the adsorption mechanism of Ca ion on talc surface is very crucial for understanding the performance of CMC on talc depression.In this paper,mechanism insights into hydrated Ca ion adsorption on talc(001) basal surface were creatively provided using DFT calculation.[Ca(H_(2)O)_6]^(2+) and [Ca(OH)(H_(2)O)_(3)]^(+) were determined as the effective hydrate components for Ca ion adsorption,and the top O site was the most favorable position for their adsorptions on talc surface.Furthermore,the adsorption mechanisms of [Ca(H_(2)O)_6]^(2+) and [Ca(OH)(H_(2)O)_(3)]^(+) on talc surface were found to be not the Ca-O chemical bond,but the hydrogen bonding formed by the H atom of the H_(2)O ligand and the surface O atom.H_(2)O acted like a bridge to connect them to the talc surface.Moreover,the hydrogen bonding was formed due to the hybridization of H 1s orbital with the O 2s,O 2p orbitals.Simultaneously,electrons transferred between the H atom and the surface O atom.This work provides theoretical insights into the Ca ion adsorption on talc surface,which can help deeply understand the talc flotation using CMC as depression.

New insight into the adsorption of ruthenium,rhodium,and palladium from nitric acid solution by a silica-polymer adsorbent

A porous silica-polymer-based adsorbent,isoBuBTP/Si O2-P,was prepared by a vacuum impregnation method and used for the recovery of ruthenium,rhodium,and palladium from nitric acid solution.The experimental results revealed that iso Bu-BTP/SiO2-P exhibited unique adsorption properties such as high saturation adsorption capacity(Ru:0.35 mmol g^-1,Rh:0.32 mmol g^-1,Pd:1.05 mmol g^-1)and excellent selectivity over other metal ions,such as lanthanides(SF(PGM/M)>40)in 1 M HNO3 solution.The adsorption process conformed to the pseudosecond-order model and Langmuir model.From the UV,FTIR,and XPS analyses,it can be concluded that the strong affinity between functional groups(C–N=C)and metal ions as well as NO3-played a role in coordination during the adsorption process.Furthermore,the desorption behavior was studied,and it was found that the adsorbed Pd,Rh,and Ru could be eluted with a 0.01 M nitric acid–0.1M thiocarbamide solution,5M hydrochloric acid,and sodium hypochlorite(CP)solution,respectively.Finally,based on those findings,a simple process for the separation and recovery of Pd,Rh,and Ru from high-level liquid waste using iso Bu-BTP/SiO2-P was designed and proposed.

Microstructure evolution and mechanical properties of high-boron steel with different ratios of boron and carbon

Boron and carbon contents are the main factors influencing the properties of high-boron steel.In this study,experimental samples with different boron-to-carbon ratios(%B/%C)were prepared.The microstructures of the different samples were observed,and their hardness,bending strength,and impact toughness were investigated.Results show that the main microstructures in the investigated high-boron steel samples are the eutectic Fe_(2)B structure with a fishbone shape and the ternary peritectic Fe_(3)(C,B)structure with a chrysanthemum shape.When the boron content is 2.5wt.%and the carbon content is 0.43wt.%(i.e.,%B/%C=5.82),the overall mechanical properties of the alloy are the best.The alloy's hardness,bending strength and impact toughness reach their maximums,which are 67.3 HRC,1,267.36 MPa and 6.19 J·cm^(-2),respectively.The optimized alloy is compared with conventional materials exhibiting excellent wear resistance(namely,high-manganese steel and high-chromium cast iron)through two-body and three-body abrasion tests.The wear resistance of this high-boron steelinvestigated in this work is found to be superior to those of the more common materials.

Vanadium-based compounds and heterostructures as functional sulfur catalysts for lithium-sulfur battery cathodes

Lithium-sulfur(Li-S)batteries have attracted wide attention for their high theoretical energy density,low cost,and environmental friendliness.However,the shuttle effect of polysulfides and the insulation of active materials severely restrict the development of Li-S batteries.Constructing conductive sulfur scaffolds with catalytic conversion capability for cathodes is an efficient approach to solving above issues.Vanadium-based compounds and their heterostructures have recently emerged as functional sulfur catalysts supported on conductive scaffolds.These compounds interact with polysulfides via different mechanisms to alleviate the shuttle effect and accelerate the redox kinetics,leading to higher Coulombic efficiency and enhanced sulfur utilization.Reports on vanadium-based nanomaterials in Li-S batteries have been steadily increasing over the past several years.In this review,first,we provide an overview of the synthesis of vanadium-based compounds and heterostructures.Then,we discuss the interactions and constitutive relationships between vanadium-based catalysts and polysulfides formed at sulfur cathodes.We summarize the mechanisms that contribute to the enhancement of electrochemical performance for various types of vanadium-based catalysts,thus providing insights for the rational design of sulfur catalysts.Finally,we offer a perspective on the future directions for the research and development of vanadium-based sulfur catalysts.

Hybrid assembly of conducting nanofiber network for ultra-stretchable and highly sensitive conductive hydrogels

Conductive hydrogels have attracted extensive attention owing to their promising application prospects in flexible and wearable electronics.However,achieving both high sensitivity and mechanical robustness remains challenging.Herein,a novel and versatile conductive hydrogel based on the hybrid assem-bly of conductive cellulose nanofiber(CNF)networks has been designed and fabricated.Assisted by the templating effect of CNFs and stabilizing effect of negatively charged poly(styrene sulfonate)(PSS),conducting polymer poly(3,4-ethylenedioxythiophene)(PEDOT)was self-organized into three-dimensional nanostructures which constructed a robust conductive network after in-situ oxidative polymerization.The unique structure derived from CNF bio-template endowed polyacrylamide(PAM)hydrogels with improved electrical conductivity and excellent mechanical performance.As a result,the as-fabricated CNF/PEDOT:PSS/PAM hydrogel exhibited an ultimate tensile strain of 1881%and toughness of 3.72 MJ/m^(3),which were 4.07 and 8.27 times higher than the CNF-free hydrogel,respectively.More significantly,the resultant hydrogel sensor showed highly desirable sensing properties,including remarkable sensing range(1100%),high gauge factor(GF=5.16),fast response time(185 ms),and commendable durability,as well as good adhesiveness.Moreover,the hydrogel sensor was able to distinguish subtle physiological activities including phonation and facial expression,and monitor large human body motions such as finger flexion and elbow blending.Besides,it was feasible to integrate the strain sensor on the joints of robots to recognize complicated machine motion signals,showing potential in advanced human-machine interactions.

3D‑Printed Carbon‑Based Conformal Electromagnetic Interference Shielding Module for Integrated Electronics

Electromagnetic interference shielding(EMI SE)modules are the core com-ponent of modern electronics.However,the tra-ditional metal-based SE modules always take up indispensable three-dimensional space inside electronics,posing a major obstacle to the integra-tion of electronics.The innovation of integrating 3D-printed conformal shielding(c-SE)modules with packaging materials onto core electronics offers infinite possibilities to satisfy ideal SE func-tion without occupying additional space.Herein,the 3D printable carbon-based inks with various proportions of graphene and carbon nanotube nanoparticles are well-formulated by manipulating their rheological peculiarity.Accordingly,the free-constructed architectures with arbitrarily-customized structure and multifunctionality are created via 3D printing.In particular,the SE performance of 3D-printed frame is up to 61.4 dB,simultaneously accompanied with an ultralight architecture of 0.076 g cm^(-3) and a superhigh specific shielding of 802.4 dB cm3 g^(-1).Moreover,as a proof-of-concept,the 3D-printed c-SE module is in situ integrated into core electronics,successfully replacing the traditional metal-based module to afford multiple functions for electromagnetic compatibility and thermal dissipa-tion.Thus,this scientific innovation completely makes up the blank for assembling carbon-based c-SE modules and sheds a brilliant light on developing the next generation of high-performance shielding materials with arbitrarily-customized structure for integrated electronics.

Flexible transparent wood enabled by epoxy resin and ethylene glycol diglycidyl ether

Transparent wood has potential application in intelligent building,solar cell,electronics,and other advanced materials,while its single functionability hinders its further development.Flexible transparent wood(FTW)was prepared by alkaline pretreatment and bleaching treat-ment of paulownia wood followed by impregnation of epoxy resin and ethylene glycol diglycidyl ether(EDGE).The eff ect of delignifi cation degree on the optical and mechani-cal properties of FTW was studied,and the infl uence of the epoxy/EDGE ratio on the fl exibility and mechanical proper-ties of FTW was also investigated.The results showed that higher delignifi cation degree resulted in higher transmit-tance of FTW.More EDGE addition led to better fl exibility of FTW,while overmuch addition of EDGE will reduce the mechanical properties.The optimal FTW sample resulted in a high transmittance of 89%and an ultrahigh haze value of 97%with outstanding fl exibility and excellent mechanical properties.The investigation of FTW broadens the research fi eld of transparent wood,and provides great possibility for its application in fl exible wearable devices and fl exible materials.

Effect of phosphate-based sealing treatment on the corrosion performance of a PEO coated AZ91D mg alloy

This study investigated the effect of sealing treatment on the corrosion performance of plasma electrolytic oxidation(PEO)coated AZ91D Mg alloy with and without addition of corrosion inhibitor.The microstructure,phase composition and corrosion property of the sealed and unsealed coatings were evaluated by using scanning electron microscopy(SEM),energy dispersion spectroscopy(EDS),x-ray diffraction(XRD),x-ray photoelectron spectroscopy(XPS),polarization,and electrochemical impedance spectroscopy(EIS)tests.Electrochemical experiments and salt spray tests showed that,after sealing in phosphate solution containing corrosion inhibitor,the corrosion current density of PEO-coated AZ91D decreased more than 10-fold and the anti-corrosion time in a salt spray environment increased more than three-fold.The corrosion rate of the PEO coating slowed down due to the releasing and adsorbing of the corrosion inhibitors in the pores and cracks of the coating during the corrosion process.

Stain capacity of three fungi on two fast-growing wood

We investigated the stain of fast-growing wood(Cunninghamia lanceolate,CL;Paulownia,PT)inoculated with three fungi(Arthrinium phaeospermum,AP;Vibrio anguillarum,VA;Aspergillacea,AS)to explore the new wood dyeing ways and the better combination of wood and fungi for dyeing.Only AP could dye on CL and PT.Especially for CL,its percentage of internal spalting,percentage of external spalting and dyeing depth were the highest(48%,15%and 5.06 mm,respectively).Surprisingly,the bigger weight loss occurs on PT.The results showed that the dyeing eff ect of AP dyeing CL was the best,and the wood color change was obviously(Orange to dark red).AP could produce more pigments than the other two fungi(VA;AS),CL was more suitable for fungus staining than PT,indicating that AP could off ered a new potential market and a chance for areas to earning higher income for CL.This research paves the way for improving color change was obviously(Orange to dark red).AP could produce more pigments than the other two fungi(VA;AS),CL was more suitable for fungus staining than PT,indicating that AP could off er a new potential market and a chance for areas to earn higher income for CL.

Effect of Al Layer on Oxidation Behavior of NbCrAl Coating

NbCrAl coatings in the presence or absence of Al outer layer were prepared on C103 Nb based alloy and alumina substrate by direct current magnetron sputtering technique. The oxidation performance of coating systems was evaluated by isothermal oxidation tests. The element diffusion and oxidation behavior of the coating systems were investigated. The results indicate that the mass gains of NbCrAl and Al/NbCrAl coatings are 2.02 mg/cm^2 and 0.79 mg/cm^2 at 1 000 ℃ for short time. Al/NbCrAl coatings exhibit more effective protection than NbCrAl coatings. The addition of Al layer can improve the oxidation resistance of NbCrAl coatings, which is attributed to the Al layer offering enough Al content to react with oxygen to form a continuous and dense Al_2O_3 scale on NbCrAl coating and it can inhibit the further internal oxidation.

Frequencies Prediction of Laminated Timber Plates Using ANN Approach

Cross laminated timber(CLT)panels,which are used as load bearing plates and shear panels in timber structures,can serve as roofs,walls and floors.Since timber is construction material with relatively less stiffness,the design of such structures is often driven by serviceability criteria,such as deflection and vibration.Therefore,accurate vibration and elastic properties are vital for engineered CLT products.The objective of this research is to explore a method to determine the natural frequencies of orthotropic wood plates efficiently and fast.The method was developed based on vibration signal processing by wavelet to acquire the effective sample data,and a model developed by artificial neural network(ANN)to achieve the prediction of nature frequencies.First,experiments were performed to obtain vibration signals of single-layer plates.The vibration signals were then processed by wavelet packet transform to extract the eigenvectors,which served as the samples to train the ANN model.The trained model was employed to predict three nature frequencies of other test specimens.The results showed that the proposed method can produce predicted frequencies fast and efficiently within 10%of the measured values.

Perspective on low-temperature electrolytes for LiFePO 4-based lithium-ion batteries

The olivine-type lithium iron phosphate(LiFePO_(4))cathode material is promising and widely used as a high-performance lithium-ion battery cathode material in commercial batteries due to its low cost,environmental friendliness,and high safety.At present,LiFePO_(4)/C sec-ondary batteries are widely used for electronic products,automotive power batteries,and other occasion-related applications with good thermal stability,stable cycle performance,and low room-temperature self-discharge rate.However,LiFePO_(4)-based battery applications are seriously limited when they are operated in a cold climate.This outcome is due to a considerable decrease in Li+transport capabilities within the elec-trode,particularly leading to a dramatic decrease in the electrochemical capacity and power performance of the electrolyte.Therefore,the design of low-temperature electrolytes is important for the further commercial application of LiFePO_(4) batteries.This paper reviews the key factors for the poor low-temperature performance of LiFePO_(4)-based batteries and the research progress of low-temperature electrolytes.Spe-cial attention is paid to electrolyte components,including lithium salts,cosolvents,additives,and the development of new electrolytes.The factors affecting the anode are also analyzed.Finally,according to the current research progress,some viewpoints are summarized to provide suitable modification methods and research suggestions for improving the practicability of LiFePO_(4)/C commercial batteries at low temperat-ures in the future.

Surface modification of Li_(3)InCl_(6)provides superior electrochemical performance for LiMn_(2)O_(4)cathode materials

Li Mn_(2)O_(4)(LMO)is the substance of choice for small and medium-sized energy storage materials in daily life.In this work,Li3InCl6(LIC)is prepared on the surface of LiMn_(2)O_(4)by hydrothermal method using InCl_(3)and LiCl as raw materials.This method stabilizes the LMO crystal structure by uniformly coating the LIC on the LMO surface and effectively maintains the morphology of LMO crystals during the cycling process.SEM and EDS analysis confirm the morphology and homogeneity of the synthesized material LIC on the LMO surface.The prepared material is put into a battery,and the charge-discharge test is carried out at 0.5 C and 1 C.The results show that the LIC surface-modified samples exhibit more than 6%higher cycling performance than the unmodified samples after long cycling.

一种新型药剂方案浮选分离黄铁矿和铜金硫化矿的案例研究:第一性原理计算的视角

由于石灰的大量使用容易导致堵管、环境污染、贵金属回收困难等问题,以石灰(CaO)为抑制剂、黄药(如丁基黄药钠)(BX)为捕收剂的传统方案的使用越来越受到限制,无石灰浮选工艺越来越被提倡。本研究创新性地提出了以Z200为捕收剂、焦没食子酸(PGA)为抑制剂的新工艺,并应用于湖北某铜金硫化矿与黄铁矿的分离。在实验室试验中,该试剂方案得到了比常规浮选工艺更好的铜金硫化矿与黄铁矿分离指标。利用基于密度泛函理论(DFT)的第一性原理计算进一步研究新药剂方案分离机理。DFT模拟结果表明,PGA对黄铁矿的抑制作用比黄铜矿强,而Z200对黄铜矿的捕收能力比黄铁矿强,这在分子水平上解释了新药剂方案的效果。这一新型环保药剂方案在矿产资源利用中具有很大的应用潜力。