Toward high-sulfur-content,high-performance lithium-sulfur batteries:Review of materials and technologies

Lithium sulfur batteries(LSBs)are recognized as promising devices for developing next-generation energy storage systems.In addition,they are attractive rechargeable battery systems for replacing lithium-ion batteries(LIBs)for commercial use owing to their higher theoretical energy density and lower cost compared to those of LIBs.However,LSBs are still beset with some persistent issues that prevent them from being used industrially,such as the unavoidable dissolution of lithium polysulfide intermediates during electrochemical reactions and large volume expansion(up to 80%)upon the formation of Li_(2)S,resulting in serious battery life and safety limitations.In the process of solving these problems,it is necessary to maintain a high sulfur content in the cathode materials to ensure that the LSBs have high energy densities and excellent cycle performance.In this review,the novel preparation methods and cathode materials used for preparing LSBs in recent years are reviewed considering the sulfur content and cycle performance.In addition,the problems and difficulties in practically applying cathode materials are described,and the development trend is discussed.

Regulation of carbon distribution to construct high-sulfur-content cathode in lithium-sulfur batteries

Lithium-sulfur(Li-S)battery is regarded as one of the most promising next-generation energy storage systems due to the ultra-high theoretical energy density of 2600 Wh kg^(-1).To address the insulation nature of sulfur,nanocarbon composition is essential to afford acceptable cycling capacity but inevitably sacrifices the actual energy density under working conditions.Therefore,rational structural design of the carbon/sulfur composite cathode is of great significance to realize satisfactory electrochemical performances with limited carbon content.Herein,the cathode carbon distribution is rationally regulated to construct high-sulfur-content and high-performance Li-S batteries.Concretely,a double-layer carbon(DLC)cathode is prepared by fabricating a surface carbon layer on the carbon/sulfur composite.The surface carbon layer not only provides more electrochemically active surfaces,but also blocks the polysulfide shuttle.Consequently,the DLC configuration with an increased sulfur content by nearly 10 wt%renders an initial areal capacity of 3.40 mAh cm^(-2) and capacity retention of 83.8%during 50 cycles,which is about two times than that of the low-sulfur-content cathode.The strategy of carbon distribution regulation affords an effective pathway to construct advanced high-sulfur-content cathodes for practical high-energy-density Li-S batteries.

A crosslinking hydrogel binder for high-sulfur content S@pPAN cathode in rechargeable lithium batteries

High-energy density lithium-sulfur(Li-S) batteries have received intensive attention as promising energy storage system.Among diverse sulfur-based cathodes,sulfurized pyrolyzed poly(acrylonitrile)(S@pPAN)cathode delivered superior electrochemical performance.However,the sulfur content of S@pPAN is relatively low(<50 wt%),which significantly limits the energy density.Herein,a hydrogel SA-Cu binder was proposed with a crosslinking network constructed by Cu^(2+) ions.The introduction of Cu^(2+) ions enabled excellent electrochemical behaviors of S@pPAN cathode even with high sulfur content of 52.6 wt% via chemical interaction with sulfur and polysulfide.Moreover,a favorable cathode interphase was formed containing electrochemically active and conductive CuSx.S@pPAN/SA-Cu exhibited a high sulfur utilization of 85.3%,long cycling stability over 1000 cycles and remarkable capacity of 1200 mAh g_(s)^(-1) even at10 C.Furthermore,ascribed to the improved electrode structure,high-loading electrode(sulfur loading:4 mg cm^(-2)) displayed stable cycling with areal capacity of 5.26 mAh cm^(-2)(1315 mAh g_(s)^(-1)) after 40 cycles.This study provides new directions to prepare high-sulfur content and high-loading S@pPAN cathode for higher energy density.

Preparation of High Ga Content Cu(In,Ga)Se₂Thin Films by Sequential Evaporation Process Added In₂S₃

High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2Se3+ In2Se3) ratio was varied from 0 to 0.13, and the properties of the thin films were investigated. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The S/(Se+S) mole ratio in the thin films was within the range from 0 to 0.04. The band gaps of Cu(In,Ga)Se2 thin films increased from 1.30 eV to 1.59 eV with increasing the ?In2S3 /(Ga2Se3+ In2Se3) ratio.

内蒙古某含碳高硫锌锡矿石选矿试验研究

内蒙古某含碳高硫锌锡矿石锌品位1.02%、锡品位0.86%,硫和碳含量分别为14.02%、1.68%。矿石矿物组成较复杂,主要有用矿物为闪锌矿、锡石和黄铁矿,脉石矿物主要为石英、绿泥石和绢云母等。为确定矿石合理的开发利用工艺,采用预先脱碳—浮重联合工艺流程开展选矿试验研究。结果表明,矿石经预先脱碳、1粗1扫1精锌硫混选、1粗1扫3精锌硫分离浮选流程处理,闭路试验可得到Zn品位为45.16%、Zn回收率为71.19%的锌精矿,S品位为46.92%、S回收率81.91%的硫精矿;浮选尾矿采用摇床重选,经粗选、精选、复选和中矿再选,可获得Sn品位45.52%、Sn回收率81.99%的锡精矿,以及Sn品位3.13%、Sn回收率11.09%的锡中矿。所设计试验流程较好地解决了矿石中有机碳对浮选的不利影响,综合回收了有价矿物,可为同类矿石的开发利用提供理论借鉴。

带报警装置爆破片在高含硫天然气放空系统中的应用

高含硫天然气生产现场常见爆破片等安全保护装置,标准中规定爆破片更换周期2-3年,期间爆破片破裂难以及时发现,给安全生产带来隐患。基于姜一昌、温殿江等人设计的一种爆破片运行状态监测装置理论研究,在爆破片环缝圆板上设计1根固定报警导线,爆破片破裂时环缝圆板张开将其上固定的报警导线拉断,通过信号远传让操作人员及时发现爆破片破裂,从而第一时间更换爆破片。现场应用表明:带报警装置爆破片能够让值班室操作人员迅速发现爆破片破裂并及时更换爆破片,可有效预防长明火场站的火源通过破裂的爆破片越过阻火器进入气田水罐,防止安全生产事故的发生,对长明火和阻火器易堵塞的高含硫场站具有一定的推广应用价值。

土壤中全硫测定——硫分析仪选择及方法优化

全硫含量是土壤调查项目中的必测项目。在燃烧法直接测定固体样品的硫分析仪中,高频红外碳硫仪检测限低,检测速度快,燃烧温度高,测定土壤标准物质的准确度高,是快速测定土壤中全硫的最佳仪器。应用高频红外碳硫仪测定样品过程中,坩埚空白、通氧流量、样品称样量、助熔剂添加量、定量方法等均会对测定结果准确度产生影响。通过对上述影响条件进行优化,研究确定了测定土壤中全硫含量的最佳条件:在严格控制坩埚空白的前提下,通氧流量设定为2~3 L/min,依次称取0.1 g样品(精度:0.0001 g)、0.5 g纯铁(精度:0.001 g)和1.0 g钨粒助熔剂(精度:0.001 g)混合后上机分析,对不同浓度样品进行分段校正。值得注意的是,本研究证实了利用化学物质标准品建立工作曲线的可行性,为后期仪器优化和改进提供了宝贵思路。国家土壤标准物质测定结果的相对标准偏差(RSD)小于2%(n=6),测定值与标准值相对误差(RE)的绝对值小于1%(n=6),方法检出限为4.50μg/g,说明方法的准确度和精密度高,适用于低含硫量土壤样品的批量检测。

分子动力学模拟在石油管材腐蚀与防护中的应用

当前油田开采面临着高温高压、高Cl^(-)、高含硫等日渐复杂的工况环境,石油管材的耐蚀性能以及防护技术的适用性面临较大挑战,分子动力学模拟技术因其不受实验条件的限制且具有广尺度特点可弥补传统评价方法的不足。本文首先简述了分子动力学模拟技术的基本原理;并基于分子动力学模拟应用,阐述了管材在Cl^(-)、CO_(2)/H_(2)S等体系中的分子动力学腐蚀机理研究,概述了分子动力学在研究防腐涂层中的研究应用。最后,对分子动力学模拟技术今后在耐蚀材料研发中发展方向进行了展望,以期为油气田用新材料的研制、防护技术的应用提供理论基础与技术支持。

Sulfur polymerization strategy based on the intrinsic properties of polymers for advanced binder-free and high-sulfur-content Li–S batteries

Lithium-sulfur(Li-S)batteries are the promising next-generation secondary energy storage systems,because of their advantages of high energy density and environmental friendliness.Among numerous cathode materials,organosulfur polymer materials have received extensive attentions because of their controllable structure and uniform sulfur distribution.However,the sulfur content of most organosulfur polymer cathodes is limited(S content<60%)due to the addition of large amounts of conductive agents and binders,which adversely affects the energy density of Li-S batteries.Herein,a hyperbranched sulfur-rich polymer based on modified polyethyleneimine(Ath-PEI)named carbon nanotubeentangled poly(allyl-terminated hyperbranched ethyleneimine-random-sulfur)(CNT/Ath-PEI@S)was prepared by sulfur polymerization and used as a Li-S battery cathode.The high intrinsic viscosity of Ath-PEI provided considerable adhesion and avoided the addition of PVDF binder,thereby increasing the sulfur content of cathodes to 75%.Moreover,considering the uniform distribution of elemental sulfur by the polymer,the utilization of sulfur was successfully improved,thus improving the rate capability and discharge capacity of the battery.The binder-free,sulfur-rich polymer cathode exhibited ultra-high initial discharge capacity(1520.7 mAh g^(−1) at 0.1 C),and high rate capability(804 mAh g^(−1) at 2.0 C).And cell-level calculations show that the electrode exhibits an initial capacity of 942.3 mAh g^(−1) electrode,which is much higher than those of conventional sulfur-polymer electrodes reported in the literature.

降低铅冶炼底吹炉高铅渣含硫量的生产实践

某铅冶炼厂采用“富氧底吹氧化-氧气侧吹还原”工艺进行粗铅冶炼,底吹炉产出的高铅渣含硫量较高,达到1.3%~1.6%,对后续尾气脱硫系统造成一定影响,环保处理成本升高。为了解决该问题,本文结合理论和生产实践分析了铅冶炼底吹炉高铅渣含硫高的主要原因。高铅渣中的硫主要以硫酸根形态存在,这些硫酸根一部分来自入炉物料中的硫酸盐类铅物料,另一部分则是在熔炼过程中由硫化铅精矿发生氧化反应生成的。降低高铅渣含硫量的主要途径是提高熔池熔炼的温度和降低系统中SO_(2)的分压。结合生产实践从渣型、氧料比、入炉粒矿含硫、系统SO_(2)分压等方面探讨了降低底吹炉高铅渣含硫量的途径和方法。在含铅渣料搭配比例30%左右,控制渣温1050~1100℃,控制渣型FeO/SiO_(2)1.4~1.8,CaO/SiO_(2)0.4~0.6;氧料比100~110 Nm^(3)/t,入炉粒矿有效硫12.5%~13.5%及适当负压等相关工艺参数组合条件下,可使高铅渣残硫保持在1.2%以下。

川东北飞仙关高含硫地层油基钻井液复合除硫技术

川东北地区飞仙关组气藏属于高含硫气藏~特高含硫气藏,针对川东北飞仙关高含硫气藏地质特点和钻井液技术难点分析,提出油基钻井液复合除硫技术对策。通过室内实验优选出除硫效果好的除硫剂,并进行了优选除硫剂复合配方优化研究和除硫剂高温老化除硫效果评价实验。研究表明,复合配方3%YT-3+3%CLC-2+3%JD-2的H_(2)S预防率高达99.14%,清除率达到100%,具有优良的除硫能力,复合配方中的锌基类除硫剂与钻井液中的H_(2)S反应生成稳定的难溶硫化物(ZnS),三嗪类除硫剂和醇醚酰胺类除硫剂主要通过物理和化学反应作用除硫,反应比较迅速,且不可逆,能够去除钻井液中的硫化氢,消除硫化氢对钻井液性能的影响和对钻具的腐蚀。该复合除硫技术在坡005-X4井和坡002-H5井飞仙关高含硫地层现场应用非常成功,在钻进过程中以及起下钻循环排后效期间地面均未检测到H_(2)S气体溢出,钻井液中S^(2−)含量始终监测为零,充分说明复合除硫技术除硫效果显著,能够满足高含硫井钻进的要求,为下川东高含硫气藏钻井工程除硫剂的优选提供良好借鉴。

连续重整装置液化气硫含量高原因分析及对策

在连续重整装置运行期间,产生的液化气一旦硫含量过高,不仅将导致副产物质量不佳,还将影响装置整体运行效果。以某项目为例,对液化气硫含量高的原因展开分析,在确定液化气硫来源的基础上,结合工艺流程判断影响硫含量的因素,逐一完成进料硫含量、设备运行参数、换热器故障等原因排查,最终确定液化气硫含量超标与汽提塔换热器内漏有关,通过修复内漏和合理注入缓蚀剂成功降低了液化气硫含量,为装置可靠运行提供保障。

煤炭中硫含量测定方法的应用分析

为了解决煤炭中硫含量测定周期长、测定精度差的不足,提出了一种新的煤炭中硫含量测定技术。主要是利用高温水解+离子色谱测定的方法,先将煤炭样品进行高温水解,然后利用微孔过滤膜进行精细化过滤并利用阴离子分离柱进行分离,最后再利用离子色谱仪进行测定。根据实际应用表明,新的测定方案能够将测试周期降低46.4%,将测试偏差降低到1.2%以内,极大地提升了煤炭中硫含量测定效率和精确性。

离子色谱法测定高含硫污水氯化物的前处理方法应用

氯化物是判定炼油装置设备腐蚀程度的重要指标之一,炼油装置产生的污水含有大量的硫化物和氨氮等干扰物质,给实验室准确测定氯化物带来很大困难。本文通过探索运用一种新的样品前处理方式,分析塔河高含硫污水的氯化物含量,并结合试验过程,对分析结果进行重复性和加标考察试验,得出试验方法多次平行测定相对标准偏差为0.69%~3.33%,加标回收率为101.5%~116.8%,验证了此前处理方法的可靠性和分析结果的准确性。

湿法消解-火焰原子吸收光谱法测定铋精矿中银含量

由于铋精矿中含有大量的硫元素和硅元素,测定铋精矿中银的含量时,王水无法将其完全消解,导致样品溶解不完全,使得测量结果偏低。本研究采取在样品前处理加入高氯酸与氟化氢铵的方法来消解硫元素和硅酸盐化合物,然后采用火焰原子吸收光谱仪(AAS)测定铋精矿中银的含量,有效解决了铋精矿中较高的硫含量和硅含量对样品溶解及测定过程中的影响。试验过程中,采用2.0 mL高氯酸、0.2 g氟化氢铵、王水体系溶解铋精矿,在体积比20%HCl介质条件下,利用火焰原子吸收光谱仪测得铋精矿样品中的银含量,结果表明,本试验方法检出限为0.0066μg/mL,低于测定下限0.022μg/mL,表明本试验方法可行,能够满足铋精矿中银含量的测定要求;利用该方法测定样品中银含量,相对标准偏差(RSD,n=7)为0.20%~1.95%,加标回收率为97.7%~105.0%;综合元素干扰测定过程中没有产生明显的基体效应干扰。该方法适用于铋精矿中50.0~10000.0 g/t银的测定,为企业和检测机构开展铋精矿中银含量的测定提供了一种更为简便、实用性更强的分析检测方法。

Graphene/RuO2 nanocrystal composites as sulfur host for lithium-sulfur batteries

An optimized graphene/RuO2/S composite is prepared by hydrothermal growth of RuO2 particles on graphene oxide sheets as the positive electrode for rechargeable lithium-sulfur batteries. The electrode with 6.1 wt% RuO2 nanocrystals and a high sulfur content of 79.0 wt% delivers an optimal electrochemical performance with high residual capacities of 508 mAh g-1 after 200 cycles and 389 m Ah g-1 after800 cycles at 1 C with a low capacity decay of 0.054%. The RuO2 nanocrystals promote the redox reaction kinetics and facilitate the transformation of sulfur chemistry, leading to large improvements in reversibility and rate capability of the composite electrode. The density functional theory calculations signify the formation of Li–O and Ru–S bonds through chemical interactions between RuO2 and Li polysulfides while the adsorption energies between graphene and polysulfide species are much higher in the presence of RuO2 than that of the neat graphene acting alone. These discoveries support the efficient entrapment of polysulfides by the composite electrode to the benefit of enhanced cyclic stability of the battery.

碳酸盐岩气藏注CO_(2)埋存及提高采收率机理研究进展

四川盆地碳酸盐岩气藏具有分布广、埋藏深、高温高压、含H2S、边底水活跃、非均质性强等特征,若能将CO_(2)注入到高含硫碳酸盐岩有水气藏中,可以达到CO_(2)埋存和提高天然气采收率双重目的;但常规实验和经典理论难以揭示其复杂机理。为此,文中分析了高含硫碳酸盐岩气藏注CO_(2)埋存及提高天然气采收率开采过程中存在的主要问题,详细论述了高含硫碳酸盐岩气藏注CO_(2)埋存及提高采收率机理研究进展,并提出了未来发展方向。

普光气田气井硫堵动态特征及治理对策研究

普光气田属于特高含H_(2)S气田,随着气田的开发,地层压力逐渐降低,单质硫逐渐从天然气中析出,附着沉积在地面设备、集输管线以及油管内壁,造成硫沉积堵塞。目前,普光气田地面集输流程和井筒均已出现硫沉积与堵塞,严重影响气井正常生产。针对气井硫沉积堵塞动态特征不清,缺乏相应的硫堵治理对策的难题,首先,开展单质硫在天然气中的含量实验研究,明确了原始地层条件下天然气中单质硫的含量,不同压力和温度条件下的单质硫饱和溶解度;其次,研究了地面流程硫沉积堵塞和井筒硫沉积堵塞的动态特征及变化规律,提出了地面硫堵和井筒硫堵的治理对策,评价了各类措施的效果及现场适应性;最后,根据理论研究及现场实践,分析认为硫堵会逐渐发展到储层,前瞻性地提出了储层解硫堵的对策。研究成果对高含硫气井的地面-井筒-储层硫堵综合治理具有很强的指导意义。

The construction of technical standard system for ultra deep and high sour gas fields in Northeast Sichuan

To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful experiences and failure lessons of project construction technology application scientifically, Sinopec has established an integrated technical standard system for the exploration and development of ultra deep and high sour gas fields. The system consists of 51 enterprise standards and covers 7 professions including geophysical prospecting, drilling, drilling log, well logging, gas formation test and production, sour gas gathering and transferring system, and HSE (health,safety,environment). It guides and guarantees the safe, high-quality and high-efficiency project construction effectively by means of enhancing the engineering design criterion, recommending the data processing and interpretation methods, identifying the requirements of operation and field inspection and standardizing the application of technical equipments.

陕北某高含硫采出水水质分析及回注处理工艺评价

通过对墩洼联合站中高含硫采出水水质进行详细地分析,总结出该油田采出水水质特点。同时,提出采出水处理工艺流程和存在的问题,并给出建设性意见与评价,对采出水达标处理和有效回注提供了技术指导。采用油田水分析方法等标准得出其水样中不同工艺段各离子的含量;对比连续5 d内的水质分析得出各个离子含量的变化。结果表明:该站所处理的采出水属于高含硫污水,并且来水中的腐蚀及成垢离子较多,导致处理后水样中的硫含量未能达到回注标准,且对于管线等的腐蚀较为严重。以期为陕北含硫采出水的回注处理工艺提供参考。