新型固体电解质Li_(8.5)Ga_(0.5)GeP_2S_(12)

制备了一种新型固体电解质Li8.5Ga0.5GeP2S12。用XRD、SEM、恒电流间歇滴定技术(GITT)和恒电流恒电压测试对其物相、形貌、离子导电性、锂离子的扩散系数和电池的充放电特性等进行了分析。Li8.5Ga0.5GeP2S12属于三斜晶系,P1空间群;固态电解质锂离子电池在3.30V、4.01V、4.18V时锂离子扩散系数(14.4×10-10 cm2·s-1、1.47×10-10 cm2·s-1、0.58×10-10 cm2·s-1)和液态电解液组成的锂离子电池的离子扩散系数(17.4×10-10cm2·s-1、2.02×10-10 cm2·s-1、0.75×10-10 cm2·s-1)基本处于一个数量级;固态电解质Li8.5Ga0.5GeP2S12在低倍率下放电容量比液态电解质稍低,而在高倍率下放电容量比液态电解质要高;固态电解质Li8.5Ga0.5GeP2S12有很优异的耐高温安全性,在130℃、2h热箱实验中电池没发生明显体积变化,而相同条件下的液态电解质锂离子电池已发生严重涨气。     

全固态锂离子电池用PEO基聚合物电解质的研究进展

锂离子电池作为重要的能量储存元件在消费类电子产品、电动汽车和可再生能源存储等领域具有广泛的应用。传统液态电解质锂离子电池受到能量密度低、安全性差等诸多缺陷的限制,采用固态电解质替代液态电解质制备新型固态锂离子电池目前备受关注。PEO基固态聚合物电解质由于其设计简单、易于制造、使用安全等优点已被认为是替代传统液体电解质的首选。介绍了当前PEO基聚合物电解质的主要研究种类、特点和性能;阐述了锂离子在PEO基聚合物电解质中的导电机制;分析了与PEO络合的锂盐种类对聚合物电解质的电导率的影响规律;在此基础上提出了几种改善PEO基聚合物电解质性能的措施和方法。     

离子液体复合体系改性PEO制备新型固态聚合物电解质

固态聚合物电解质（SPE）因其独特的安全性能受到越来越多的关注。在此,以新型聚离子液体（PIL）/离子液体（IL）共混改性聚环氧乙烷（PEO）,制备了一种PEO基高性能固态聚合物电解质。利用X射线衍射（XRD）、热重（TG）方法探究了样品的晶体结构和热稳定性,研究结果表明,PIL/IL的引入,显著降低了结晶度,同时表现出较高的热稳定性（320℃）。通过电化学阻抗（EIS）、线性扫描伏安（LSV）等方法研究了固态聚合物电解质的电化学性能,研究结果表明,结晶度的降低显著地提高了离子电导率(2.27×10^-4 S·cm^-1, 40℃)和锂离子迁移数（0.3, 40℃）,同时由于咪唑环C（2）位上的质子氢被烷基取代,提高了电化学窗口（4.8 V）。通过组装LiFePO₄/Li全电池进行充放电测试,发现其稳定放电容量高达150 mAh·g^-1,100次循环后放电容量保持不变,库伦效率保持在99%以上,展现出较高的容量和循环稳定性。     

DOPO-KH560改性聚氧化乙烯聚合物固态电解质的制备及性能

利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)改性3-缩水甘油氧基-丙基三甲氧基硅烷(KH560)合成了阻燃效果优异的硅/磷协效阻燃剂,并与聚氧化乙烯(PEO)、锂盐复合制备聚合物固态电解质,研究其对PEO基电解质的热稳定性和电化学性能的影响。通过对聚合物固态电解质的组成、热稳定性和电化学性能研究表明,当DOPO-KH560质量分数为10%,n(EO)∶n(Li~+)=8∶1时,DOPO-KH560/PEO/LiTFSI电解质的室温电导率高达1.8×10~(-4) S/cm,在4.9 V以下能够保持电化学稳定;以该电解质制备的LiFePO_4/Li半电池可以在80℃下稳定使用,在0.2 C电流密度、循环80次后可逆比容量为136.5 mA·h/g,具有优异的循环稳定性。     

聚离子液体复合PEO制备高性能全固态聚合物电解质

用化学共沉淀法固态聚合物电解质(SPE)因其独特的安全性能受到越来越多的关注。以聚环氧乙烷(PEO)为基体,通过引入聚离子液体(PIL),制备了一种新型SPE(PIL@PEO SPE)。通过将PIL穿插于PEO链段中,有效降低了PEO的结晶度,提高了SPE的离子电导率(6.63×10^-4 S/cm)。由其制备的固态电池在0.5C,60℃时,Li/LiFePO4电池首次放电容量高达147.6 mAh/g,经过长达300圈充放电循环,容量保留率仍然在90%以上。     

交联网状结构聚硅氧烷类固体电解质的制备及电化学性能研究

采用硅氢加成交联的方法制备了具有网络结构的聚硅氧烷固体电解质,采用热重分析、交流阻抗、线性扫描伏安法对电解质进行表征,考察了锂盐含量以及温度对电解质离子电导率的影响。结果表明:电解质在常温下电导率最大可以达到1.74×10~(-4)S/cm,热稳定性在220℃达到最佳,电化学窗口可达到5V(vs.Li/Li~+);电解质与锂电极的稳定性较好。将聚合物电解质组装成LiFePO_4/SPE/Li锂离子电池,电池在0.07C倍率下,充放电比容量达到160mAh/g,充放电平台在3.45V左右;在0.15C倍率下,电池循环26圈后,电池充放电比容量保持在134mAh/g,库伦效率保持在98%以上。     

二氧化锰—石墨烯复合电极材料的制备与表征

利用水热法制备MnO_2和MnO_2-石墨烯(GNs)复合材料,并分别作为锂离子电池的负极材料,进行XRD、SEM、恒电流充放电(GC)、循环伏安(CV)和交流阻抗(EIS)等测试。结果表明,制备的MnO_2为β-MnO_2,长度为1~2μm,宽度小于200 nm的纳米棒。β-MnO_2-GNs复合材料在0.1 C的电流密度下循环60次的放电比容量为659.8 m A·h/g,放电容量保持率为46.4%,在5C电流密度下,放电比容量保持在418 m A·h/g。     

纳米SiO2/LiClO4/PVDF-HFP复合凝胶聚合物电解质的制备及其电化学性能

为了解决液态电解质锂离子电池存在的安全性问题,以偏氟乙烯和六氟丙烯的共聚物(PVDF-HFP)为基体,通过加入高氯酸锂(LiC1O4)、增塑剂(碳酸丙烯酯和碳酸二甲酯)、纳米二氧化硅等,制备出了具有高电导率的复合凝胶聚合物电解质.用X射线衍射仪测试聚合物电解质的结构,用交流阻抗法测定其电导率,用线性伏安扫描法研究了该聚合物电解质体系的电化学稳定性,并以其为电解质制备成锂离子电池进行充放电测试.结果表明,在20℃时复合凝胶聚合物电解质的电导率最高可达7.56×10-3S/cm,该电解质在4.6 V以下电化学窗口稳定,以其为电解质的锂离子电池具有良好的电化学性能,说明纳米SiO2/LiC1O4/PVDF-HFP复合凝胶聚合物电解质能满足锂离子电池的应用.     

PEO基聚合物电解质

聚氧化乙烯（PEO）基电解质是研究最早的聚合物电解质体系，它在电池生产中已得到应用。PEO基聚合物电解质主要分为聚合物/盐型和凝胶型两大类，凝胶型聚合物电解质因具有较高的电导率而被认为是固态锂离子电池最有应用前景的临时性解质体系。对两种类型的聚合物电解质的研究进展作了较为详细的论述，在此基础上分析了PEO基聚合物电解质中离子的传输机理。PEO基聚合物电解质中离子的运动能力与链的结构。离子浓度，温度，增塑剂等因素有关。     

锂离子电池电解液产业分析

一、锂离子电池电解质技术概况锂离子电池制造所需的正极材料、负极材料、隔膜和电解质材料被称为锂离子电池4大关键材料,其中,锂离子电池电解质按其存在形态大致可以分为液态电解质、凝胶态电解质和固态电解质3种。从1991年全球第一只商业化锂离子电池诞生至今,锂离子电池电解质材料呈现出从液态到固态逐步发展的过程。现阶段,在电解质市场居统治地位的是液态电解质,一     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.