热喷涂MoS2/PA复合涂层的摩擦学性能及磨损机理研究

热塑性聚合物基复合涂层由于其耐介质，耐磨，耐腐蚀等优良性能而得到广泛应用。火焰热喷涂是一项具有发展前景的制备聚合物复合涂层的技术。本文考察了火焰喷涂二硫化钼填充的PA聚合物复合涂层摩擦学性能，并研究不同填料含量对涂层摩擦学性能影响的机理。     

长寿命热电池用复合阴极材料的研究

通过对锂化的五氧化二钒制备过程中,材料配比、添加剂对锂化的五氧化二钒阴极材料的影响、单体电池放电实验等进行研究,发现锂化的五氧化二钒阴极材料具有更高的电压和更好的热稳定性,但锂化的五氧化二钒阴极材料的库仑比容量比较低,影响长寿命热电池的后期放电电压,以锂化的五氧化二钒材料为主、添加一定比例ＥＬＦＴ的复合阴极材料,其综合性能优于锂化的五氧化二钒和ＥＬＦＴ这两种阴极材料,应用于长寿命热电池中,取得了比     

CNT/α-MnO_2复合正极对锂空气电池性能的影响研究

作为锂空气电池的关键组成部分之一,正极材料性质对锂空气电池的性能起到重要影响。以CNT为碳载体,以α-MnO_2为催化剂,制备CNT/α-MnO_2复合电极作为电池正极。通过恒流定容充放电测试、深度充放电测试、循环伏安测试、电化学阻抗谱测试和扫描电镜测试,研究CNT/α-MnO_2复合正极材料对锂空气电池性能的影响,并获得最优电极材料配比。研究表明:制备的CNT/α-MnO_2复合电极表现出高循环稳定性和高催化活性,显著提升了锂空气电池的性能;当正极材料中CNT与α-MnO_2的质量比为3∶6时,装备CNT/α-MnO_2复合正极的锂空气电池表现出最佳性能,其循环次数高达170次。     

低熔点合金在电连接头中的应用性能研究

针对输配电线路电连接头发热导致能源损耗甚至引发事故的问题,文中研究了低熔点合金在电连接头中的应用性能。选用在铜界面上润湿性较好的低熔点合金Sn-3.5Ag、Sn-1.6Cu、Sn-Zn-0.7Cu,设计其在电连接中的连接工艺并制作试样。利用ERESCO MF4便携式X光机判断连接后界面的可靠性,再搭建SLQ-2000A升流实验系统并模拟实际工况。最后,测试了低熔点合金和电力复合脂试样在额定通流值为180 A时,持续通流时间4 h过程中试件的发热情况。研究结果表明,低熔点合金作为电连接接触面材料后试样的发热量均低于电力复合脂连接试样的发热量。     

铝固体电解电容器电解质研究进展I.TCNQ型铝固体电解电容器

综述了TCNQ及其复合盐的合成方法,TCNQ复合盐型铝固体电解电容器的制造工艺,以及铝固体电解电容器用电解质──7,7,8,8-四氰基对苯二醌二甲烷(TCNQ)复合盐的研究进展。目前,高耐热TCNQ复合盐电解质已经研究成功。TCNQ复合盐型铝固体电解电容器已有引线式和片式两种类型。     

铝固体电解电容器电解质研究进展 Ⅰ.TCNQ型铝固体电解电容器

综述了TCNQ及其复合盐的合成方法,TCNQ复合盐型铝固体电解电容器的制造工艺,以及铝固体电解电容器用电解质--7,7,8,8-四氰基对苯二醌二甲烷(TCNQ)复合盐的研究进展.目前,高耐热TCNQ复合盐电解质已经研究成功.TCNQ复合盐型铝固体电解电容器已有引线式和片式两种类型.     

NrGO-RuO_(2)复合正极对有机电解液锂空气电池性能影响研究北大核心CSCD

动力电池作为新能源汽车最重要的部分之一,它的容量直接决定了新能源汽车续航里程的长短。随着新能源汽车的普及,具有高能量密度的锂空气电池成为了目前的研究热点之一。而高性能的空气正极对提升锂空气电池电化学性能至关重要。采用水热法制备氮掺杂石墨烯/二氧化钌(NrGO-RuO_(2))复合正极,通过X射线衍射、X射线光电子能谱、扫描电子显微镜和氮气(N_(2))等温吸-脱附等测试对其晶体结构、元素组成、表面形貌和孔隙结构进行分析,并通过恒流定容充放电、深度放电、电化学交流阻抗图谱等测试分析其对锂空气电池性能的影响。研究表明:与rGO和rGO-RuO_(2)复合正极相比较,NrGO-RuO_(2)复合正极具有较高的循环、深度放电性能和较低的电荷转移阻抗。装配NrGO-RuO_(2)复合正极的锂空气电池,循环次数达到90次,放电深度达到4309 mAh/g,电荷转移阻抗为39.27Ω·cm^(2)。     

S 波段移相器用锂铁氧体材料的研制

论述了锁式移相器中对铁氧体材料的要求和 S 波段锂铁氧体的制备及性能.文中分析了添加剂 Ti、Zn、Mn 等离子对锂铁氧体电磁性能的影响及使用方法,通过陶瓷工艺制备得到性能良好的复合锂铁氧体材料,材料具有饱和磁化强度和磁感应强度的温度系数低、矫顽力小、容易驱动等特点,满足宽温带 S 波段移相器的要求.此方法也适用于高频移相器材料.     

锂硫电池正极材料NiO/CNT的制备及性能研究

锂硫电池在电动汽车、无人机等领域受到极大的关注,因其环境友好、材料成本低、理论容量高等特点而被广泛研究,但因硫的导电性能不佳、多硫化物的穿梭效应以及充放电过程中硫的体积变化等阻碍了锂硫电池的商业化。为改善硫不良的导电性及多硫化物的穿梭效应,基于碳材料优异的导电性与氧化物较强的吸附性,采用水合肼在CNT表面还原氯化镍,通过热处理后得到NiO/CNT复合物作为硫的载体,充当电池的正极。物理及电化学表征的结果表明,多孔结构的NiO/CNT比表面积达到48.49 m²·g^-1,在电流密度为1C下,NiO/CNT的首圈比容量达到825 mAh·g^-1,循环100圈后,比容量保持在617 mAh·g^-1且库伦效率在99.3%以上,说明两种材料的复合提高了电池库伦效率和循环性能。     

铝固体电解电容器电解质研究进展 Ⅱ.导电聚合物型铝固体电解电容器

综述了聚吡咯(PPY)、聚苯胺和聚(3,4–次乙二氧基噻吩)(PEDOT)等导电高分子材料在铝固体电解电容器中应用的最新研究情况。聚吡咯型铝固体电解电容器明显好于TCNQ复合盐型电容器。聚苯胺和聚(3,4–次乙二氧基噻吩)型铝固体电解电容器是尚在研究还未商业化的两类新品种,后一类因其高导电性、高环境稳定性,而最具发展前景。     

大功率LED散热用高导热硅脂的研制

以二甲基硅油为基础油,通过添加不同粒径和含量的Al、Cu、Ag、AlN、SiC和石墨,制备了单一填料的单组分以及两种填料大小搭配的二元混合导热硅脂,研究了硬脂酸表面处理、填料种类、大小及比例对导热硅脂热导率的影响,得到了以下结果:硬脂酸处理能提高单组份Al、AlN硅脂的导热性能,但不适用于提高含石墨、SiC、Cu的硅脂的性能;填料填充的最佳比例在0.55~0.60之间;以Ag微粒作为第二填料增强Al和AlN为主填料的硅脂时,对导热率的增强效果高于AlN和Cu、Ag/AlN二元混合硅脂热导率5.5W·m-1·K-1。将制备的导热硅脂用于LED散热,结果表明自制导热硅脂实际散热效果优于市购热界面材料。     

硅油及填料对导热硅脂接触热阻的影响

文中研究了不同种类硅油、不同金属氧化物导热填料及其颗粒直径大小分布、不同偶联剂种类等因素对导热硅脂产品的接触热阻、导热系数、界面厚度、粘度、耐渗油性等性能的影响。结果证明:二甲基硅油与球形氧化铝导热填料搭配使用可以获得更高的填料填充量,通过加入偶联剂可大大降低导热硅脂产品的粘度并提高导热硅脂的耐渗油性,而适中的导热填料颗粒大小分布以及较小的界面厚度可以得到高导热系数以及超低接触热阻的导热硅脂产品。     

Mechanically Robust and Highly Conductive Ionogels for Soft Ionotronics

Ionogels are promising materials for flexible electronics due to their continuous conductive phase, high thermal and chemical stability. However, a large amount of ionic liquid is required to get high conductivity, resulting in a sharp decline in the mechanical properties. Therefore, it is a great challenge to prepare ionogels with both high conductivity and mechanical properties, which is important for their practical applications. Herein, ionogels with high mechanical strength and stretchability, extraordinary ionic conductivity, excellent transparency, outstanding durability, and stability are fabricated with crosslinked polymer, ionic liquid, and lithium salt. The adoption of lithium salt can significantly improve both the mechanical strength and stretchability, which is a common dilemma in material science, and simultaneously, address the conflict between mechanical strength and ionic conductivity in ionogels. It is primarily corresponding to the microphase-separation effects induced by the lithium bonds formed between lithium ions and carbonyl groups on the polymer networks. Ionotronics including resistance-type sensors for strain and temperature sensing and triboelectric nanogenerators with stable output performance are fabricated. Moreover, ionogel-based microcircuit and sensing arrays with high resolution and accuracy are fabricated through digital light processing printing technology. The ionogels have great promise for various ionotronics in many fields.     

锂无机固态电解质研究进展

对商业化的传统液态电池存在的问题及无机固态电解质相较于传统液态电解质在安全性和能量密度等方面的优势进行了简单阐述.介绍了目前研究较多的硫化物型、钠超离子导体(NASICON)型、钙钛矿型、石榴石型和锂超离子导体(LISICON)型五种无机固态电解质的化学组成和晶体结构及锂离子导电机制,并对其离子电导率、电化学窗口、电子...     

Thermal contact resistance of cured gel polymeric thermal interface material

This paper reports the experimental results on the contact resistance of curable polymer gel thermal interface materials (TIMs) that have different mechanical properties due to difference in the rheology of the polymers. A semi-analytical model for the prediction of the thermal contact resistance of cured gel TIMs is also introduced in this paper. A novel method of finding the transition from grease type behavior to gel type behavior, which is very important for post reliability stress performance, based on G' (storage shear modulus) and G' (loss shear modulus) measurements is reported. Further, post thermal cycling thermal resistance degradation rate of gel TIMs are related to the ratio of G and G'. Finally, design guidelines for gel TIMs for use in flip-chip packages comprising heat spreaders are proposed.     

Succinonitrile as a Versatile Additive for Polymer Electrolytes

Solid polymer electrolytes with high ionic conductivities are prepared by using poly(ethylene oxide) (PEO) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (P(VDF‐HFP)) as polymer matrixes, succinonitrile (SN) as an additive, and lithium bis‐trifluoromethanesulfonimide (LiTFSI) and lithium bisperfluoroethylsulfonylimide (LiBETI) as salts. In these systems, the introduction of succinonitrile into the polymer electrolytes increases the material's ionic conductivity and conveys excellent mechanical properties. The described composites, with their beneficial combination of mechanical and electric properties, are expected to have significant potential for lithium batteries.     

Electronic Conductivity and Defect Chemistry of Heterosite FePO4

Electrochemical investigations on polycrystalline orthorhombic FePO₄ (heterosite), the lithium‐poor part of the LiFePO₄/FePO₄ redox couple, gives insight into its charge‐carrier chemistry. The material obtained by chemical delithiation exhibits a predominant electronic conductivity. A residual lithium content of 0.03 wt% was found and has to be considered as lithium interstitials in the FePO₄ ground structure. Compensation by electrons induces n‐type conduction, confirmed by the pO₂ dependence of the electronic conductivity. The pO₂ dependence is primarily ascribed to the formation of an oxidic surface composition leading to bulk depletion of lithium, rather than to filling of oxygen vacancies.     

PIM-1 as a Multifunctional Framework to Enable High-Performance Solid-State Lithium–Sulfur Batteries

Poly(ethylene oxide) (PEO) is a promising solid electrolyte material for solid-state lithium–sulfur (Li–S) batteries, but low intrinsic ionic conductivity, poor mechanical properties, and failure to hinder the polysulfide shuttle effect limits its application. Herein, a polymer of intrinsic microporosity (PIM) is synthesized and applied as an organic framework to comprehensively enhance the performance of PEO by forming a composite electrolyte (PEO-PIM). The unique structure of PIM-1 not only enhances the mechanical strength and hardness over the PEO electrolyte by an order of magnitude, increasing stability toward the metallic lithium anode but also increases its ionic conductivity by lowering the degree of crystallinity. Furthermore, the PIM-1 is shown to effectively trap lithium polysulfide species to mitigate against the detrimental polysulfide shuttle effect, as electrophilic 1,4-dicyanooxanthrene functional groups possess higher binding energy to polysulfides. Benefiting from these properties, the use of PEO-PIM composite electrolyte has achieved greatly improved rate performance, long-cycling stability, and excellent safety features for solid-state Li-S batteries. This methodology offers a new direction for the optimization of solid polymer electrolytes.     

Cu材料激光表面强化研究

采用激光技术对Cu基材进行表面强化处理。使用扫描电镜(SEM)、电子能谱计(EDS)和X射线衍射仪(XRD)对强化表面进行显微组织和物相分析,并测试了样品的显微硬度、耐磨性能和导电性能。结果表明,激光强化层无裂纹,组织细小均匀、呈快速凝固特征,强化层具有较高的硬度(平均硬度为625HV0.1)和良好的耐磨性,其磨损失重仅为纯Cu基材的1/5,而激光表面强化使导电性略微降低。激光表面强化层硬度和耐磨性的提高可归因于颗粒强化、细晶强化和固溶强化的共同作用,而导电性的降低程度主要受稀释率的影响。     

Improvement of charge/discharge performance for lithium ion batteries with tungsten trioxide electrodes

Although a large amount of research on Li ion transportation has been carried out with the aim of improving the properties of lithium ion batteries, there has been little detailed research on electron conduction. Hence, we have been focusing on improving the charge/discharge performance of lithium ion batteries by increasing the electron conductivity of the electrodes. The electron conductivity of crystalline tungsten trioxide (WO₃) was found to be increased by N₂ annealing owing to the generation of oxygen vacancies. It was clarified that increasing the conductivity of the electrodes can improve the performance of lithium ion batteries, particularly their charge/discharge speed and reversibility. Additionally, the best performance was observed in a sample subjected to high-temperature annealing at 700 °C in N₂ ambient, which decreased the resistivity of the WO₃ electrode by five orders of magnitude and simultaneously changed the monoclinic crystalline structure into a cubiclike structure into which Li ions are more easily intercalated. Therefore, to enhance the charge/discharge performance of lithium ion batteries, electron conduction should be a focus of research. Crystalline WO₃ was also demonstrated to be a promising material for electrodes since oxygen vacancy generation can be induced by a simple annealing treatment, improving the electron conduction and Li ion transportation.