The application of nanostructured transition metal sulfides as anodes for lithium ion batteries

With wide application of electric vehicles and large-scale in energy storage systems, the requirement ofsecondary batteries with higher power density and better safety gets urgent. Owing to the merits of hightheoretical capacity, relatively low cost and suitable discharge voltage, much attention has been paid tothe transition metal sulfides. Recently, a large amount of research papers have reported about the appli-cation of transition metal sulfides in lithium ion batteries. However, the practical application of transitionmetal sulfides is still impeded by their fast capacity fading and poor rate performance. More well-focusedresearches should be operated towards the commercialization of transition metal sulfides in lithium ionbatteries. In this review, recent development of using transition metal sulfides such as copper sulfides,molybdenum sulfides, cobalt sulfides, and iron sulfides as electrode materials for lithium ion batteriesis presented. In addition, the electrochemical reaction mechanisms and synthetic strategy of transitionmetal sulfides are briefly summarized. The critical issues, challenges, and perspectives providing a fur-ther understanding of the associated electrochemical processes are also discussed.

Advanced metal sulfide anode for potassium ion batteries

Potassium-ion batteries（KIBs） are a promising alternative to lithium-ion batteries owning to the abundance of potassium on Earth and the relatively low K/K＋redox couple. To date, KIBs remains its infancy and the investigation of anode materials mainly focused on carbon-based materials, which deliver limited reversible capacity. Hence, it is imperative to explore alternative anode materials with high reversible capacity for KIBs. Recently, a pioneering work from Chen’s group reported a nanocomposite of Sb2S3 nanoparticles anchored on porous S,N-codoped graphene（denoted as Sb2S3-SNG） as an advanced anode material for KIBs, which exhibited remarkable enhancements of both capacity and cycling stability, highlighting the rational structure design of Sb2S3-SNG for maximum utilization of Sb2S3 nanoparticles and graphene layers for energy storage applications in high-performance KIBs.

Effect of temperature, chloride ions and sulfide ions on the electrochemical properties of 316L stainless steel in simulated cooling water

The influence of temperature, chloride ions and sulfide ions on the anticorrosion behavior of 316L stainless steel in simulated cooling water was studied by electrochemical impedance spectroscopy and anodic polarization curves. The results show that the film resistance increases with the solution temperature but decreases after 8 days’ immersion, which indicates that the film formed at higher temperature has inferior anticorrosion behavior; Chloride ions and sulfide ions have remarkable effects on the electrochemical property of 316L stainless steel in simulated cooling water and the pitting potential declines with the concentration of chloride ions; the passivation current has no obvious effect; the rise of the concentration of sulfide ions obviously increases the passivation current, but the pitting potential changes little, which indicates that the two types of ions may have different effects on destructing passive film of stainless steel. The critical concentration of chloride ions causing anodic potential curve’s change in simulated cooling water is 250 mg/L for 316 L stainless. The effect of sulfide ions on the corrosion resistance behavior of stainless steel is increasing the passivation current density Ip. The addition of 6 mg/L sulfide ions to the solution makes Ip of 316 L increase by 0.5 times.

Adsorption characteristics of Pb(Ⅱ)ions on sulfidized hemimorphite surface under ammonium sulfate system

In this work,the effect of ammonium sulfate on the adsorption characteristics of low-concentration Pb(Ⅱ)ions on the sulfidized hemimorphite surface was comprehensively investigated.The results showed that ammonium sulfate could increase the maximum recovery of hemimorphite from 69.42%to 88.24%under a low concentration of Pb(Ⅱ)ions.On the hemimorphite surface pretreated with ammonium sulfate,the adsorption of Pb(Ⅱ)ions was enhanced and the main species of Pb adsorbed was changed from Pb―O/OH to PbS.This was due to the larger amount of ZnS providing more effective adsorption sites for Pb components to generate Pb S.Meanwhile,the intensity of ZnS decreased with the formation of PbS,demonstrating that ZnS was covered by PbS which formed later on the mineral surface.It was beneficial for the adsorption of butyl xanthate on the hemimorphite surface to form more hydrophobic substances.As a result,ammonium sulfate played a crucial role in realizing the efficient recovery of hemimorphite.

Cobalt Sulfide Confined in N-Doped Porous Branched Carbon Nanotubes for Lithium-Ion Batteries

Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.

1-Hydroxyethylidene-1,1-diphosphonic Acid (HEDP) as a Corrosion Inhibitor of AISI 304 Stainless Steel in a Medium Containing Chloride and Sulfide Ions in the Presence of Different Metallic Cations

The novelty of this paper is the analysis in a medium containing sulfide ion due to the generation of this ion in petroleum industries, in the refining stage (the sulfide ion is also present on the produced water). The performance of 1-hydroxyethylidene-1,1-diphosphonic acid inhibitor (HEDP) was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements in a dissolution of AISI 304 stainless steel immersed in a solution containing chloride and sulfide ions. The protection of the stainless was increased with the addition of divalent cations (Ca2+, Zn2+, and Mg2+). Potentiodynamic polarization studies have shown that the inhibitor alone has anodic protection, but the addition of Ca2+ (10 mg·L-1) favors the cathodic protection, and the addition of Zn2+ (20 mg·L-1) and Mg2+ (10 mg·L-1) mixed-type is observed. Electrochemical impedance spectroscopy was performed at three distinct potentials: -0.3 [V vs. SCE], Ecorr [V vs. SCE], and 0.1 [V vs. SCE]. This revealed that calcium is responsible for favoring the formation of the film and the other elements (zinc and magnesium) favor the stabilization of the protective film. Scanning electron microscopy analysis revealed that the addition of cations provided the adsorption of HEDP on the metal surface. Weight loss results showed that the presence of zinc in a solution containing HEDP favored greater inhibitor efficiency (Zn2+ ηm = 85.2% and for Mg2+ ηm = 70.4%).

Mechanism of influence of ferric ion on electrogenerative leaching of sulfide minerals with FeCl_3

A dual cell system was used to study the influence of ferric ion on the electrogenerative leaching of sulfide minerals. Reaction mechanisms for the ferric chloride electrogenerative leaching of a series of sulfide minerals were proposed based on the data collected from the dual cell experiments. The influences of ferric ion on the electrogenerative leaching of sulfide minerals are similar. Ferric ion plays an important role on limiting the electrogenerative leaching rate at a relatively low concentration of FeCl3 (about less than 0.15 mol/L). The mathematical models based on the Butler-Volmer relation were delineated, and kinetic equations with respect to ferric ions for each sulfide mineral were obtained. The kinetic equations show that when the concentration of ferric ion is relatively low, the electrogenerative leaching rates are predicted to be proportional to 6/7, 4/5, 2/3 and 2/3 order of ferric ion for nickel concentrate, chalcopyrite concentrate, sphalerite and galena respectively. As the concentration of ferric ion increase, the correlative dependence between electrogenerative leaching rate and concentration of ferric ion becomes weak. The above conclusions are in agreement with the experimental results.

Mechanism of influence of chloride ions on electrogenerative leaching of sulfide minerals

A dual cell system was used to study the influence of chloride ions on the electrogenerative leaching of sulfide minerals. The results show that the influences of chloride ions on a series of electrogenerative leaching system are similar, and chlorine ion is involved in the electrogenerative leaching process of sulfide minerals directly. The output power increases with the increase of Cl^- concentration. The influence on the electrogenerative leaching rate decreases when the Cl^- concentration reaches a certain value. The mechanisms of anodic reaction are deduced based on the reasonable hypothesis, and kinetic equations with respect to chlorine ions for each sulfide mineral are obtained. The kinetic equations show that when concentration of Cl^- is relatively low, the electrogenerative leaching rates are predicted to have 25, 27, 13 and 13 order dependence on Cl^- concentration for chalcopyrite concentrate, nickel concentrate, sphalerite and galena. As concentration of Cl^- increases, the correlative dependence of electrogenerative leaching rate on concentration of Cl^- becomes weak.

Behavior Mechanism on Sulfide Solid-Liquid Interface and Its Application

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Adsorption behavior and mechanism of copper ions in the sulfidization flotation of malachite

Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy(XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.

Enabling Argyrodite Sulfides as Superb Solid-State Electrolyte with Remarkable Interfacial Stability Against Electrodes

While argyrodite sulfides are getting more and more attention as highly promising solid-state electrolytes(SSEs)for solid batteries,they also suffer from the typical sulfide setbacks such as poor electrochemical compatibility with Li anode and high-voltage cathodes and serious sensitivity to humid air,which hinders their practical applications.Herein,we have devised an effective strategy to overcome these challenging shortcomings through modification of chalcogen chemistry under the guidance of theoretical modeling.The resultant Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)delivered excellent electrochemical compatibility with both pure Li anode and high-voltage LiCoO_(2)cathode,without compromising the superb ionic conductivity of the pristine sulfide.Furthermore,the current SSE also exhibited highly improved stability to oxygen and humidity,with further advantage being more insulating to electrons.The remarkably enhanced compatibility with electrodes is attributed to in situ formation of helpful electrolyte–electrode interphases.The formation of in situ anode–electrolyte interphase(AEI)enabled stable Li plating/stripping in the Li|Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)|Li symmetric cells at a high current density up to 1 mA cm^(-2)over 200 h and 2 mA cm^(-2)for another 100 h.The in situ amorphous nano-film cathode–electrolyte interphase(CEI)facilitated protection of the SSE from decomposition at elevated voltage.Consequently,the synergistic effect of AEI and CEI helped the LiCoO_(2)|Li_(6.25)PS_(4)O_(1.25)Cl_(0.75)|Li full-battery cell to achieve markedly better cycling stability than that using the pristine Li_(6)PS_(5)Cl as SSE,at a high area loading of the active cathode material(4 mg cm^(-2))in type-2032 coin cells.This work is to add a desirable SSE in the argyrodite sulfide family,so that high-performance solid battery cells could be fabricated without the usual need of strict control of the ambient atmosphere.

Sb_(2)S_(3)/石墨烯负极材料的制备及其储钠性能研究

钠离子电池(sodium-ion batteries,SIBs)具有成本低的潜在优势,有望成为替代锂离子电池(lithium ion batteries,LIBs)的储能设备。为提升钠离子电池的性能,开发出适应钠离子脱嵌的负极材料尤为重要。硫化锑(Sb_(2)S_(3))因其理论比容量高被认为是较好的钠离子电池负极材料。本文使用简单水热法将Sb_(2)S_(3)与石墨烯复合,制备Sb_(2)S_(3)/石墨烯复合材料(Sb_(2)S_(3)/Gr)。结果表明:Sb_(2)S_(3)/Gr作为钠离子电池负极时,不仅表现出良好的电导率(3.5×10~(-3)S/cm)和钠离子扩散速率(4.853×10~(-13)cm~2/s),而且在0.5 A/g的电流密度下,首圈库伦效率为76.27%,经150次循环后的比容量稳定在488 m A·h/g,表现出较高的比容量。Sb_(2)S_(3)/Gr复合材料表现出了极大的应用潜力,为高性能钠离子电池负极材料的研发提供了一定的参考价值。

全固态硫化物锂电池中NCM正极及其界面研究

采用硫化物电解质的全固态锂电池被视作解决传统液态锂电池安全问题与能量密度提升的最有效方案。正极材料作为锂电池的主要组成部分之一,很大程度上决定着全固态锂电池的基本性能。镍钴锰酸锂(NCM)三元体系正极材料因具备能量密度较高和成本较低的优点,以及与硫化物电解质的可兼容性而受到广泛关注。然而,NCM三元材料存在安全性低、循环稳定性差等缺点,与硫化物电解质接触界面仍存在许多问题亟待解决。因此,分析和研究NCM三元正极材料的结构组成和界面优化,对于提高全固态锂电池稳定性和安全性具有重要的意义。聚焦于当前主流三元正极材料以及与硫化物固态电解质界面问题的匹配性研究,阐述了NCM三元正极材料在全固态锂电池应用中所面临的挑战、解决策略和发展机遇,并对NCM三元正极的进一步发展和应用提出展望。

湿法脱硫中多硫离子分离方法的建立

多硫离子S_(x)^(2-)是湿式催化氧化脱硫技术中H2S向单质硫转化的中间产物,在脱硫环境中,析硫反应和副盐反应存在平行竞争关系,S_(x)^(2-)的存在形态及浓度是评价两个竞争反应程度的前提条件。本文通过紫外-可见分光光度法(UV-vis)、液相色谱-质谱仪(LC-MS)和高效液相色谱(HPLC)方法可实现对S_(x)^(2-)的存在形态及各形态浓度定量测定的目标。结果表明:UV-vis法可测定出S_(x)^(2-)的总浓度;甲基化法可将S_(x)^(2-)的各个形态进行捕捉,LC-MS和HPLC法可将各形态的甲基化多硫化物分离,且S_(x)^(2-)的硫原子数(2—10)越大保留时间越长;结合UV-vis建立的标准曲线和HPLC上各个形态S_(x)^(2-)出峰的相对强度,推算出溶液中各形态S_(x)^(2-)的绝对浓度;多硫化钠溶液主要以S_(4)^(2-)、S_(5)^(2-)、S_(6)^(2-)、S_(10)^(2-)为主,其中浓度和pH对S_(x)^(2-)的影响较小,而温度过高不利于S_(x)^(2-)的生成,从而不利于单质硫的生成。这一项工作为进一步从源头上研究副盐成因及加快析硫反应的研究奠定了基础。

矿浆难免离子对铅锌硫化矿分离的影响研究进展

这是一篇矿物加工工程领域的论文。矿浆溶液中普遍存在一些难免离子,并且其中存在的难免离子对铅锌硫化矿的浮选分离有着重要影响。矿浆中难免离子主要来源于选厂用水、矿物自身溶解、活化剂或者抑制剂解离以及流体包裹体释放引入的原生离子和磨矿过程中引入的次生离子。本文对矿浆中引入的原生离子以及磨矿体系引入的次生难免离子对铅锌硫化矿浮选分离的影响进行了总结分析发现,不论是原生离子还是次生离子对铅锌硫化矿浮选行为的影响均较为明显,较多的学者针对这种现象进行了大量的研究。通过药剂调控以及改变磨矿环境等方法已经取得了较大的突破,为后续研究者提供了重要的研究思路。本文的关注点是将前人的研究成果与现场工艺紧密结合,在不影响工业经济情况下如何从源头消除难免离子,如何从现场工艺中降低难免离子对浮选指标的影响仍是未来研究的重要方向。

H_(2)S^(+)在A^(2)A_(1)(v1=1,v2=8,v3=0)激发态的光解动力学

振动激发在分子和离子的光解动力学中有着重要的作用:开展特定振动激发态分子离子的光解离动力学实验研究存在很大挑战,尤其是实现合频振动激发离子的量子态选择的制备.本文利用时间切片离子速度成像技术研究了H_(2)S^(+)离子经A^(2)A_(1)(v1=1,v2=8,v3=0)激发态解离生成S^(+)(4S)和H_(2)的光解动力学.实验结合多光子电离和共振激发技术制备了振动激发的H_(2)S^(+),获得了离子在357.02~358.38nm范围内六个光解波长下产物S^(+)的速度影像.根据实验影像,获得了产物的总平动能谱和不同转动态的角分布各项异性参数特别指出地是在很窄的光解能量范围内,转动产物H_(2)(J=1)和H_(2)(J=3)的分支比出现多次反转,该现象与A^(2)A_(1)态单一振动模式激发的H2S+离子的光解动力学行为有明显不同.该研究表明,合频振动激发的H_(2)S^(+)离子光解动力学中可能存在振动模式之间的协同效应.

Identified the hydrochemical and the sulfur cycle process in subsidence area of Pingyu mining area using multi-isotopes combined with hydrochemistry methods

Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.

SnS_(2)/SnS/NC异质结构微米花的构筑及储钾性能探究

采用水热法制备SnS_(2)微米花(MFs),以聚多巴胺衍生的氮掺杂碳(NC)作为还原剂和缓冲基质,合成了SnS_(2)/SnS/NC异质结构微米花(SSNC MFs)作为钾离子电池负极材料。SnS_(2)和SnS形成的异质界面加快了电荷的转移,进而改善了电化学动力学。同时,NC增强了复合材料的导电性和结构稳定性。因而,SSNC MFs电极在0.1 A/g下,循环50周的可逆比容量为492.4 mAh/g,2.0 A/g下仍保持在199.6 mAh/g,远大于相同测试条件下的SnS_(2) MFs电极(分别为132.1和28.4 mAh/g),表现出显著提升的可逆比容量、循环稳定性和倍率性能。

离子色谱-脉冲安培法测定空气中微量硫化氢

硫化氢(H_(2)S)是无色有毒气体,低浓度即有臭鸡蛋气味,浓度足够高时会麻痹嗅觉神经反而不易被察觉,人体长时间接触H_(2)S会使呼吸系统和中枢神经等受到严重损害。低浓度硫化氢可用离子色谱法检测,针对现有方法存在的问题,本文建立了一种准确、高效测定微量硫化氢气体的被动采样-离子色谱-脉冲安培定量分析方法。该法使用经典的IonPac AS7(250 mm×4 mm)阴离子交换色谱柱,并采用新型氢氧化钠-草酸钠淋洗液组合替代传统方法中氢氧化钠-乙酸钠淋洗液组合,优化脉冲安培检测电位参数,实现了低浓度硫化物的检测;探究提取稳定液的种类和含量对硫化物稳定性的影响,建立了硫化物的最佳保存条件。实验结果表明,硫化物在10~3000μg/L的范围内线性关系良好(相关系数r^(2)>0.999),检出限(S/N=3)和定量限(S/N=10)分别为1.53μg/L和5.10μg/L,保留时间和峰面积的相对标准偏差(RSD)均小于0.2%(n=6)。改进后方法稳定性好,操作要求低,硫化物峰形更为对称,基线噪声显著降低,且淋洗液试剂成本只有原来的10%,更适用于实际样品中低浓度硫化物的检测。采用250 mmol/L氢氧化钠-0.8%(质量分数)乙二胺四乙酸二钠稳定液可使硫化物稳定保存10 h以上,提高了回收率,使大批量、长时间检测更具可靠性。将新建立的方法应用于学校垃圾处理站附近空气中硫化氢含量的测定,检测结果均未超过国家规定限值,此法可满足硫化氢气体相关鉴定检测工作的要求。

四硫化钒复合石墨烯材料的制备及其锂离子电池性能研究

四硫化钒(VS_(4))作为具有高硫含量三明治结构的一维(1D)链状钒硫化合物,S_(2)二聚体与两个相邻的V原子配位,每个单链通过弱范德华力相互作用,松散堆叠的链有利于Li^(+)的快速扩散,因而被认为是有前途的锂离子电池负极候选者。通过水热法设计并合成了四硫化钒复合还原氧化石墨烯(VS_(4)@rGO)负极材料,VS_(4)纳米棒紧密地固定在氧化石墨烯薄片上,氧化石墨烯的加入一方面保证了良好的导电性,另一方面也抑制了VS_(4)纳米棒团聚成球以释放更多活性位点,从而有效提高锂离子电池的性能。作为锂离子电池负极,VS_(4)@rGO电池的充放电性能出色,进行倍率测试时,在0.2,0.5,1.0,2.0和5.0 A·g^(-1)的电流密度下,平均放电比容量分别为983,797,666,547和397 mAh·g^(-1)。在5 A·g^(-1)的高电流密度下可保持循环3000次,比容量稳定在141.6 mAh·g^(-1),平均每圈的容量衰减率仅为0.019%。这项工作为其他过渡金属硫化物的结构设计提供了新的思路。