Outstanding long-cycling lithium−sulfur batteries by core-shell structure of S@Pt composite with ultrahigh sulfur content

Here we proposed a novel approach to greatly enhance the electrochemical performance of Li-S batteries by designing a composite electrode material composed of a core-shell structure of S@Pt composite(sulfur content,85%)grown on the S surface.The platinum(Pt)nanosheets provide physical barrier and strong chemical binding to anchor LiPSs and improve the electronic conductivity of S.Significantly,by introducing carbon nanofibers(CNFs)as the interlayer,we achieved outstanding Li-S battery with a high initial discharge capacity of 1040 mAh g^(-1)at 1.0C and a reversible capacity of 742 mAh g^(-1)after 350 cycles,demonstrating its excellent long-term cycling stability with a low capacity decay rate of 0.08%per cycle.According to the density functional theory(DFT)calculations,we proposed that the superior performance is attributed to the cooperative effects of the strong interfacial interaction between Pt(111)surface and the S8 molecule,and very low reaction energy of decomposition,−6.4eV.

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.

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.

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.

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.

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.

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。

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.

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。

四川盆地罗家寨高含硫气田钻完井技术创新与实践

四川盆地高含硫化氢气藏储量规模较大,其安全绿色高效开发对于四川盆地千亿立方米天然气产能基地建设和国家“双碳”目标实现具有重要意义,但高含硫气田在钻完井过程中面临漏、涌、塌、卡、毒等工程技术挑战。为加快高含硫气田的安全绿色高效开发,梳理了高含硫气田钻完井技术难点,开展了高含硫气井优快钻井工艺、完井工艺、井控工艺技术攻关与实践,创新形成了适用于高含硫气田钻完井工艺技术系列。研究结果表明:①首次将海上成熟的Trulink不停泵测斜工艺和随钻测井工艺运用在国内陆上高含硫气井钻井中,分别实现四开一趟钻完钻和五开产层一趟钻完井,趟钻进尺、机械钻速、定向周期等指标优异,井身轨迹合格率100%;②超低密度领浆体系成功应对固井恶性井漏挑战,韧性防气窜泥浆体系配合顶部封隔器确保悬挂位置封固良好,固井合格率、优质率双达标;③两步式完井工艺降低完井过程井控风险,下入的井下永置式压力计实现气井全生命周期的井下实时动态监测;④优化后的防喷器组合及井控装备能够保证高含硫气田钻完井全过程的井控安全。结论认为,四川盆地罗家寨高含硫气田钻完井工艺技术创新在高质量建井方面取得了显著成效,累计测试获气590×10^(4)m^(3)/d,累计无阻流量3204×10^(4)m^(3)/d,所形成的钻完井优化工艺技术系列可以有效指导类似高含硫气田的安全规模高效开发。

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。

低密度强封堵抗硫油基钻井液在高含硫井的应用

川东北高含硫区块储层飞仙关组具有地层压力系数低、硫化氢含硫高、渗透性强等地质特点。为了解决该区块在水平段钻井过程中存在的易卡易漏、硫化氢含量高、小井眼携砂不良等井下难题,本文通过室内实验,优选了低密度强封堵抗硫油基钻井液配方,并对其性能进行了分析评价。实验结果表明,该体系具有流变性能好、封堵性强、除硫效果好等特点。现场应用结果表明,该体系表现出良好的携砂、防漏防卡、防硫除硫效果,密度最低达到1.00g·cm^(-3),高温沉降稳定性好,井壁稳定,未发生硫化氢伤害事故。该体系能很好地满足高含硫区块的安全快速钻井要求,可为高含硫井的安全高效开发提供参考。

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。

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。

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。

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。

高含量磷/硫共掺杂碳网络的制备及储钾性能的研究

为了解决掺杂碳材料中磷含量低的问题,以红磷为模板和磷源,采用等离子体增强化学气相沉积法一步合成高含量磷/硫(P/S)共掺杂碳网络材料(PSCN),并将其应用于钾离子电池。实验结果表明,P/S高含量(质量分数为31.11%)PSCN为碗状的碳网络结构,其具有碳间距大、缺陷程度高、比表面积大、微孔丰富和热稳定性好等特点。将PSCN作为钾离子电池负极时,在电流密度100 mA·g^(-1)下可逆容量达到557.1 mAh·g^(-1),在电流密度5 A·g^(-1)下可逆放电容量为140.3 mAh·g^(-1),经1 000圈循环后容量仍有137.4 mAh·g^(-1),容量保持率为69.5%,表现出优异的倍率和循环性能。而磷掺杂碳材料(PC),在电流密度100 mA·g^(-1)下的可逆容量为457.3 mAh·g^(-1),在5 A·g^(-1)下经1 000圈循环后容量仅有62.8 mAh·g^(-1),容量保持率较差为43.4%。PSCN的碗状结构有利于电解液的浸润,而其中的细小纤维可以很大程度地抑制K^(+)在嵌入/脱嵌过程中所引起的体积膨胀,从而有效地提升了钾离子电池的倍率和循环性能。此外,高含量P/S共掺杂还可以增加PSCN的活性位点,促进储钾动力学和提高离子传输能力,进而有效提升倍率性能、赝电容占比和K^(+)的扩散系数,降低反应电阻。本研究为发展钾离子电池负极材料的制备工艺提供了参考,起到理论支持作用。

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。

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。