锂离子电池负极墨水的制备及性能研究

钛酸锂因零应变特性已成为性能优异的锂离子电池负极材料,在锂离子电极负极材料有良好的应用前景,确保后期3D打印出性能良好的微电池棒状电极.选取钛酸锂作为棒状电极的负极材料,与溶剂、增稠剂、分散剂和保湿剂等按一定比例制备打印墨水,随后通过以挤压为基础的3D打印技术打印电极,并在氮气保护下高温烧结获得的棒状电极。本文主要探究了钛酸锂掺杂石墨、钛酸锂质量分数以及烧结温度对棒状电极的性能影响,其次通过打印墨水的流变特性模拟分析来探究墨水黏度对挤压过程中流动速度的影响.结果表明:掺杂10%石墨的钛酸锂棒状电极相比未掺杂石墨的电极,其充放电容量提高了18%,表现出较好的循环性能;当钛酸锂质量分数为59%,打印墨水黏度为26.53 Pa·s,所制备棒状电极的电阻率为221 kΩ·cm,打印墨水具有良好的打印及导电性能;当烧结温度为950℃,棒状电极电阻率较小,为205 kΩ·cm,与基板有良好的附着力,膜层表面平整、致密且有许多孔洞,有助于电解液的渗透.对打印墨水的黏度进行模拟分析可知,随黏度的增减而使墨水流动速度变化明显.     

国际锂离子电池回收技术路线及企业概况

正锂离子电池是由正负极片、粘结剂、电解液和隔膜等组成。在工业上,厂家主要使用钴酸锂、锰酸锂、镍钴锰酸锂三元材料和磷酸亚铁锂等作为锂离子电池的正极材料,以天然石墨和人造石墨作为负极活性物质。聚偏氟己稀(PVDF)是一种广泛使用的正极粘结剂,粘度大、具有良好的化学稳定性和物理性能。工业生产的锂离子电池主要采用电解质六氟磷酸锂(Li PF6)和有机溶剂配置的溶液作为电解液,利用有机膜,如多孔状的聚     

锂离子电池三元正极材料包覆工艺研究进展

锂离子电池三元正极材料镍钴锰酸锂因为具有放电容量高、生产成本低、层状结构稳定、热稳定性好等优点,被认为是当前最可能广泛应用的动力电池正极材料。但还存在容量保持率低、不可逆相变大、循环性能差、高温热稳定性能差等问题,表面包覆工艺被认为是一种简便有效地提高材料多项性能的方法。综述了三元正极材料镍钴锰酸锂表面包覆的方法、常用包覆物质,分析了包覆后材料性能提高的原因,并提出了包覆工艺的改善对策。     

锰系正极材料电解液添加剂研究进展

从电极表面成膜及钝化集流体等方面,分别阐述锰酸锂、镍锰酸锂、三元、富锂锰基这4种锰系正极材料常用电解液添加剂的作用机理,综述了锰系正极材料电解液添加剂的研究进展,指出深入研究电解液复合添加剂的协同作用,有助于提高锂离子电池的性能。     

聚合物磷酸铁锂动力电池的研究进展

锂离子电池正极材料 自从90年代SONY率先推出锂离子电池以来，锂离子电池行业迅猛发展，尤其是其正极材料的技术不断取得突破，已经从钴酸锂材料一枝独秀，发展成钴酸锂、锰酸锂、镍钴酸锂、镍钴锰酸锂、磷酸铁锂材料齐头并进的态势。这些材料根据其各自的特点，适用于不同的领域。     

锂离子电池三元正极材料镍钴铝酸锂(NCA)的研究进展

锂离子电池具有电压稳定、容量高、能量密度大、自放电少、循环寿命长、环境友好等优势,广泛应用于电动车、电动工具、手机、笔记本电脑等领域。正极材料是决定锂离子电池性能的关键材料,高能密度、长循环寿命和高安全性正极材料已成为世界各国研发和关注的热点。目前已经市场化的锂电池正极材料包括钴酸锂、锰酸锂、镍酸锂、磷酸盐锂、镍钴锰酸锂和镍钴铝酸锂等。     

石墨烯改性富锂镍钴锰酸锂正极材料的制备及表征

作为一种新型层状材料,富锂镍钴锰酸锂具有良好的应用前景,然而其存在一定的结构缺陷和性能差异。尝试使用石墨烯对富锂镍钴锰酸锂材料进行改性,得到性能优良的锂离子电池正极材料,并采用X射线衍射、拉曼光谱、扫描电镜等谱学技术以及恒电流充放电技术对改性后的材料进行了表征与测试。结果显示,该材料粒径较小且分布均匀,具有良好的充放电比容量(分别为251.7mAh/g和164.5mAh/g),和优良的循环稳定性。     

化学所在高性能锂离子电池电极材料上取得新进展

<正>能量密度的提升是锂离子电池领域的研究重点,而正极材料是决定锂离子电池能量密度的关键。镍锰酸锂材料是一种高电压的正极材料,具有高能量密度和良好的倍率性能;然而,其自身的高工作电压会显著加速电极材料表面的副反应,严重损害电极材料的结构稳定性和长循环性能,限制了它在高比能动力电池     

高镍三元正极材料的包覆与掺杂改性研究进展

随着新能源汽车的加速发展, 镍钴锰/铝酸锂三元正极材料、特别是高镍(镍含量大于50%)材料作为后起之秀, 由于其性能和成本的综合指标优于传统的钴酸锂和磷酸铁锂, 引起了学术界和产业界极大的研究兴趣。但是受其本身晶体结构和表面结构的限制, 三元正极材料也存在安全性较差、循环稳定性不足等缺点。近年来, 科研工作者为解决这些问题、并进一步提升三元材料的性能, 在材料改性技术方面开展了大量工作, 取得了令人瞩目的研究成果。本文从改性元素对三元正极材料结构以及对电化学性能改善的机理出发, 介绍了包覆和掺杂两种改性技术的研究进展, 并在此基础上对三元正极材料的发展方向做出展望。     

正极材料LiNi1/3Co1/3Mn1/3O2的结构、性能及制备技术研究

镍钴锰三元材料作为锂二次电池正极材料是目前国内外研究热点.综述了三元材料近几年国内外的研究状况,重点介绍了LiNi1/Co1/3Mn1/3O2的晶体结构和作为锂离子电池正极材料的电化学反应特征及热稳定性,总结了制备技术对其性能的影响,以及不同掺杂元素(Mg、Al、Ti、Cr、F等)对其的改性作用,并展望了正极材料LiNi1/3Co1/3Mn1/3O2的发展.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.