碳纳米管/氧化镍复合电极超大容量离子电容器

碳纳米管作为一种新型碳材料,具有质轻,高的有效比表面积和优良的导电性,是制备双电层电容器较为理想的电极材料。本文实验用硝酸回流处理碳纳米管,对其表面改性,通过sol-gel法在改性后的碳纳米管上沉积Ni(OH)2,经灼烧得到碳纳米管/氧化镍复合材料,制成电极装配成电容器单元。该电容器具有双电层电容和赝电容特性,其比电容量为160 F/g,频率响应特性较活性炭电极电容器有所提高,是一种极具发展潜力的储能器件。     

NiO制备工艺对超电容器比电容的影响

以硝酸镍为原料,采用sol-gel法制备Ni(OH)2,在不同温度下,用真空烧结炉和管式电阻炉对其热处理后得到NiO,与活性炭电极组成非对称超级电容器研究了NiO制备工艺对超电容器比电容影响。结果表明:Ni(OH)2经真空烧结炉处理所得NiO的比电容均高于管式电阻炉处理,在260℃保温时间为1 h真空度为0.5 Pa时比电容达最大481.15 F/g。     

超级电容器用NiO多孔薄膜电极材料的研究进展

超级电容器是一类新型绿色储能器件,特别适合在有高功率密度需求场合下使用,具有极其广阔的应用前景.NiO因价廉、来源广泛、环境友好和电化学性能优良等优点而成为备受青睐的超级电容器用正极材料.综述了国内外有关NiO多孔薄膜电极材料制备方法的最新研究进展,归纳了提高和改善其电化学性能尤其是在大电流密度工作条件下电化学电容行为的方法,最后对这一领域未来的研究热点和发展方向进行了展望.     

超级离子电容器C/NiO复合气凝胶电极材料的研究

以间苯二酚、甲醛、硝酸镍和无水碳酸钠为原料,使用溶胶-凝胶法制备碳/氧化镍复合凝胶,经CO₂超临界干燥及900℃炭化处理,得到复合碳气凝胶,电化学方法证明这种材料制备的电极具有典型的电容特性,采用1mol/L KOH电解液构成电容器单元,比电容量达263F/g,等效串联电阻小于1Ω.本文还对这种复合材料的结构形貌进行了探讨,分析了其对电容器性能的影响.     

未掺杂CdZnTe与掺铟CdZnTe晶体的热处理

对于未掺杂Cd0.9Zn0.1Te晶片,采用在Cd/Zn气氛下,以In作为气相掺杂源进行热处理;而对于低阻In-Cd0.9Zn0.1Te晶片,则采用在Te气氛下进行热处理.分别研究了不同的热处理条件,包括温度、时间、pIn或pTe等对晶片电学性能、红外透过率以及Te夹杂/沉淀相的影响.结果表明,在Cd/Zn气氛下适当的掺In热处理和在Te气氛下适当的热处理均有效地提高了晶片的电阻率,分别达到2.3×1010和5.7×109Ω·cm,同时晶片的其他性能也得到明显改善.     

未掺杂CdZnTe与掺铟CdZnTe晶体的热处理

对于未掺杂Cd0.9Zn0.1Te晶片,采用在Cd/Zn气氛下,以In作为气相掺杂源进行热处理;而对于低阻In-Cd0.9Zn0.1Te晶片,则采用在Te气氛下进行热处理.分别研究了不同的热处理条件,包括温度、时间、pIn或pTe等对晶片电学性能、红外透过率以及Te夹杂/沉淀相的影响.结果表明,在Cd/Zn气氛下适当的掺In热处理和在Te气氛下适当的热处理均有效地提高了晶片的电阻率,分别达到2.3×1010和5.7×109Ω·cm,同时晶片的其他性能也得到明显改善.     

气氛热处理对无取向硅钢组织及织构的影响

本文以鞍钢生产的50AW 600牌号的无取向硅钢为研究对象,进行常规热处理和气氛热处理试验。根据冷轧无取向硅钢退火工艺的特点,研究了退火温度和保温时间对冷轧无取向硅钢晶粒组织和织构演变的影响;同时,也研究了不同的热处理气氛对无取向硅钢织构的影响。结果表明,气氛热处理条件下的无取向硅钢的晶粒要比常态下及常规热处理条件下的晶粒粗大,且比较均匀;气氛热处理形成了有利织构,提高了其磁性能;同全氢气氛相比较,氨分解气氛更有利于50AW 600无取向硅钢有利织构的形成。     

电解电容器纸对电解电容器性能的影响

提出了对电解电容器纸的基本要求，阐述了电解电容器纸技术指标与电解电容器的性能的相互关系，强调了密度选择的重要性及含水量对产品性能的影响。介绍了电解电容器纸的一般选用方法。     

尖晶石结构的钴基金属氧化物超级电容器电极材料的研究进展

超级电容器作为一种新型储能转化设备,以其充放电时间短、循环寿命长以及功率大等优点,引起了广泛的关注。超级电容器电极材料是影响其性能的重要因素。具有尖晶石结构的钴基金属氧化物以其优异的电化学性能作为超级电容器的电极材料使用获得了极大的成功。概述了各种钴基金属氧化物的最新进展,如钴酸锌、钴酸锰、钴酸镍等,并对其未来的发展进行了展望。     

Hierarchical Composite Electrodes of Nickel Oxide Nanoflake 3D Graphene for High‐Performance Pseudocapacitors

NiO nanoflakes are created with a simple hydrothermal method on 3D (three‐dimensional) graphene scaffolds grown on Ni foams by microwave plasma enhanced chemical vapor deposition (MPCVD). Such as‐grown NiO‐3D graphene hierarchical composites are then applied as monolithic electrodes for a pseudo‐supercapacitor application without needing binders or metal‐based current collectors. Electrochemical measurements impart that the hierarchical NiO‐3D graphene composite delivers a high specific capacitance of ≈1829 F g^?1 at a current density of 3 A g^?1 (the theoretical capacitance of NiO is 2584 F g^?1). Furthermore, a full‐cell is realized with an energy density of 138 Wh kg^?1 at a power density of 5.25 kW kg^?1, which is much superior to commercial ones as well as reported devices in asymmetric capacitors of NiO. More attractively, this asymmetric supercapacitor exhibits capacitance retention of 85% after 5000 cycles relative to the initial value of the 1^st cycle.     

氧化钌在法拉第准电容器中的应用研究进展

介绍氧化钌法拉第准电容器的工作原理、特点和制造方法,还对近年来这类电容器的发展状况和存在问题进行了评述。     

Molecular Design of Mesoporous NiCo2O4 and NiCo2S4 with Sub‐Micrometer‐Polyhedron Architectures for Efficient Pseudocapacitive Energy Storage

Spinel‐type NiCo₂O₄ (NCO) and NiCo₂S₄ (NCS) polyhedron architectures with sizes of 500–600 nm and rich mesopores with diameters of 1–2 nm are prepared facilely by the molecular design of Ni and Co into polyhedron‐shaped zeolitic imidazolate frameworks as solid precursors. Both as‐prepared NCO and NCS nanostructures exhibit excellent pseudocapacitance and stability as electrodes in supercapacitors. In particular, the exchange of O^2? in the lattice of NCO with S^2? obviously improves the electrochemical performance. NCS shows a highly attractive capacitance of 1296 F g^?1 at a current density of 1 A g^?1, ultrahigh rate capability with 93.2% capacitance retention at 10 A g^?1, and excellent cycling stability with a capacitance retention of 94.5% after cycling at 1 A g^?1 for 6000 times. The asymmetric supercapacitor with an NCS negative electrode and an active carbon positive electrode delivers a very attractive energy density of 44.8 Wh kg^?1 at power density 794.5 W kg^?1, and a favorable energy density of 37.7 Wh kg^?1 is still achieved at a high power density of 7981.1 W kg^?1. The specific mesoporous polyhedron architecture contributes significantly to the outstanding electrochemical performances of both NCO and NCS for capacitive energy storage.     

Multiple Electronic Phase Transitions of NiO via Manipulating the NiO6 Octahedron and Valence Control

While the multiple Mottronic and electronic phase transitions as recently discovered in nickelates (e.g., ReNiO₃) open up a new paradigm in correlated electronic applications, these applications are largely impeded by the intrinsic material metastability of the perovskite nickelates. Herein, the study demonstrates the analogous multiple electronic phase transition properties in the thermodynamically stable NiO, compared to ReNiO₃, from both perspectives of band gap regulation and orbital filling regulation. The adjustment in band gap of NiO with t_2g⁶e_g² orbital configuration is achieved via establishing biaxial tensile or compressive interfacial strains that increase or reduce the material resistivity, respectively. The relaxor ferroelectricity of 0.7Pb(Mg_2/3Nb_1/3)O₃-0.3PbTiO₃ (PMNPT) further enables an electric field adjustable resistance switch (ΔR/R) within NiO/PMNPT heterostructure with higher performances (e.g., ΔR/R of 82% upon a bias voltage of 20 V) than the reported oxides/PMNPT heterostructure. Furthermore, the magnitude in resistance switch of the tensile strained NiO via hydrogenation associated Mottronic process reaches ≈10¹¹ that exceeds the previously reported ones. This study highlights the higher material stability and easier growth of NiO, compared to ReNiO₃, with analogous multiple Mottronic and electronic phase transition properties that pave the way to its practical applications in correlated electronics.     

沉淀转化法制备NiO及其电化学性能研究

采用沉淀转化法制备了Ni(OH)2前驱体,经300℃热处理后得到NiO粉末。用XRD和SEM对其结构和形貌进行表征,用循环伏安、恒流充放电和交流阻抗研究其电化学性能。结果表明,制备的NiO具有典型的赝电容特性。在沉淀转化温度为70℃,表面活性剂的浓度为20 mol/L条件下制备的NiO在3 mA/cm2的充放电电流密度下,其单电极比电容达383.8 F/g,电极电阻为0.25Ω,8 mA/cm2循环100次后,比电容为292.5 F/g,充放电效率为97.5%。     

A Dendritic Nickel Cobalt Sulfide Nanostructure for Alkaline Battery Electrodes

A uniform dendritic NiCo₂S₄@NiCo₂S₄ hierarchical nanostructure of width ≈100 nm is successfully designed and synthesized. From kinetic analysis of the electrochemical reactions, those electrodes function in rechargeable alkaline batteries (RABs). The dendritic structure exhibited by the electrodes has a high discharge‐specific capacity of 4.43 mAh cm^?2 at a high current density of 240 mA cm^?2 with a good rate capability of 70.1% after increasing the current densities from 40 to 240 mA cm^?2. At low scan rate of 0.5 mV s^?1 in cyclic voltammetry test, the semidiffusion controlled electrochemical reaction contributes ≈92% of the total capacity, this value decreases to ≈43% at a high scan rate of 20 mV s^?1. These results enable a detailed analysis of the reaction mechanism for RABs and suggest design concepts for new electrode materials.     

溅射功率对NiO薄膜性质的影响

在室温条件下,采用射频磁控溅射的方法在石英衬底上制备了NiO薄膜,深入研究了不同溅射功率对NiO的结构、光学和电学特性的影响。随着溅射功率的升高,NiO薄膜逐渐由非晶态薄膜转变成具有(111)择优取向的晶态薄膜,同时发现NiO薄膜在可见光区透过率较大,而在紫外光区透过率减小;随着溅射功率的升高,薄膜在可见光区域和紫外区域的光学透过率均明显减小,同时禁带宽度也减小,但导电性增强。