碳纳米管-氢氧化镍复合电极电化学电容器

采用催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极。基于该种材料的超电容器电极比容量为36 F/g。研究了在碳纳米管薄膜基体上使用电化学方法沉积氢氧化镍的新工艺,制备出碳纳米管/氢氧化镍复合电极。伏安特性曲线以及直流充放电实验证明复合电极的单电极比容量达到63 F/g,交流阻抗谱证明复合电极具有优良的阻抗特性。     

5V型活性炭基超电容器的研制

详细探讨了活性炭基超电容器的电化学特性。直流充放电、循环伏安以及交流阻抗等实验显示了采用二次刻蚀方法制备的活性炭材料具有良好的容量性能和功率特性,活性物质的比容量为173.2 F/g,在大功率充放电条件下以活性物质为电极的电容器的比能量大于5.0 Wh / kg。采用新型工艺开发的 5 V小型电容器电容量达到3 F以上且电容器电阻低于120 mΩ,具有良好的电化学特性。     

基于聚酯纤维制备纤维状柔性超级电容器

将碳纳米管(CNT)和聚吡咯纳米线(NPPy)通过超声附着到纺织纤维——聚酯纤维上,制备了CNT/NPPy/聚酯纤维复合柔性电极和全固态纤维状柔性超级电容器。通过扫描电子显微镜、傅立叶红外光谱和拉曼光谱对复合电极的形貌和结构进行表征,通过循环伏安法和充放电测试等研究了超级电容器的电化学性能。充放电测试结果表明所制备的纤维状柔性超级电容器具有较高的比容量,其表面积比容量为6.34×10–3 F/cm~2,长度比电容为0.36×10–3F/cm(充放电电流密度:1.7×10–6A/cm~2)。且其循环800圈后,电容只下降33%,当弯曲500次后,该超级电容器的电容量保持率为76%,显示出了良好的柔性和弯曲稳定性。该柔性纤维状超级电容器的制备方法步骤简单,成本低廉,所制备的柔性纤维状超级电容器可纺织到衣服面料或其他纺织品中,在便携式和可穿戴电子产品中具有潜在应用前景。     

实用化超电容器的制备与电化学性能的研究

使用高比表面积活性炭可以制备不同电容量、不同工作电压的超电容器,高比表面积活性炭的比电容量远高于普通活性炭。10 F(9V)、45 F、600 F的超电容器样品的测试结果表明,高比表面积活性炭电极的孔径结构不会影响电容器大电流充放电容量,电化学性能稳定,高比表面积活性炭是一种待开发的优良的超电容器电极材料。     

热处理对纳米α-MnO2电容特性的影响

采用化学沉淀法制备出超级电容器用纳米MnO2电极材料,研究了热处理工艺对MnO2电容性能的影响。结果表明,产物主相为α-MnO2,粒度分布较均匀,在50～100 nm;热处理温度和时间对MnO2的电容性能有着重要影响。将在300℃热处理3 h的MnO2与活性炭电极组成非对称超级电容器,循环充放电500次,容量仅衰减2.24%;在电流密度为500 mA/g时,比电容量达302.52 F/g。     

基于新型介电弹性体平行板电容器的研究

为了研究具有传感功能的可变电容器,采用新型介电弹性体材料制成平行板电容器。研究了该电容器充放电前后的外形变化及影响电容大小的因素。结果表明:在高压充放电前后,电容器的极板面积和两电极板间距离都发生了明显的变化;电容随着外加电压的增大而增大;在外加电压为6 000 V的条件下,电容随着材料预拉伸的增大出现一极大值,随后又减小,即在变化过程中存在拐点;另外,电容器的电极材料用石墨粉时要比用导电胶时电容大。     

NiO-CuO纳米材料的制备及其电化学性能

过渡金属氧化物因具有丰富的氧化还原位点、高的理论容量等特性,常被用作超级电容器的电极材料。但是,单金属氧化物的导电性普遍较差,极大限制了其电化学性能。选用泡沫镍为基底,采用静电纺丝法制备出NiO纳米纤维,并通过掺杂氧化铜制备NiO-CuO双金属氧化物电极材料。实验结果表明：在2 mol/L KOH溶液中,当电流密度为0.5 A·g^-1时,NiO电极的质量比电容为202.8 F·g^-1,5 000次循环充放电后电容保持率仅为30.28%。同等测试条件下,NiO-CuO电极的质量比电容高达410.4 F·g^-1,电容保持率为60.48%。因而,合理构建双金属氧化物作为电极材料,可充分发挥两种过渡金属的协同效应,大幅提高电极材料导电性和稳定性,进而提升电化学性能。     

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.     

聚合物支撑法制备活性炭膜材料及其超级电容性能

利用聚合物支撑法制备活性炭基碳膜材料,应用于超级电容器电极材料。研究了浓酸改性时聚合物支撑对碳膜的结构和电化学性能的影响。采用扫描电镜(SEM)、氮气等温吸脱附(BET)等方法表征材料的微观结构,采用循环伏安、恒流充放电和交流阻抗等研究其电化学电容性能。结果表明,聚合物支撑法制备的碳膜在1 A·g~(–1)的电流密度下的比电容为128.9 F·g~(–1),低于纯活性炭的比容量(173.3 F·g~(–1));但是,该碳膜在浓酸改性后的比电容达到了185.6 F·g~(–1),远高于浓酸改性的活性炭(71.1 F·g~(–1))。主要原因是支撑聚合物在高温热处理留下的碳基支撑点对于活性炭丰富的孔道结构具有保护作用。     

新型LiFePO_4/AC混合超级电容器的制备和性能研究

以橄榄石型磷酸亚铁锂(LiFePO4)为正极,活性炭(AC)为负极,制备了LiFePO4/AC混合超级电容器。通过充放电、倍率和漏电流测试,系统研究了所制混合超级电容器的电化学性能。结果表明,在正负极活性物质质量比为0.8∶1.0的条件下,混合超级电容器综合性能最佳:比容量为25.38 mAh.g–1,比能量为3.21 Wh.kg–1,分别是活性炭超级电容器的2.83倍和2.17倍,且在大倍率充放电下循环稳定性好、漏电流小,在1600 s后漏电流为0.25 mA。     

Making Fiber‐Shaped Ni//Bi Battery Simultaneously with High Energy Density,Power Density,and Safety

Fiber‐shaped batteries are widely explored for a variety of important fields such as wearable electronics, information technology, internet of things, and public health. However, it remains difficult to simultaneously achieve high energy density, power density, and safety, which has largely limited their promising applications. Here, a new type of fiber‐shaped Ni//Bi batteries with remarkable electrochemical performances is created from hierarchically 3D electrodes, where reduced graphene oxide sheets framed with Bi serve as the anode while reduced graphene oxide sheets wrapped with nickel oxide/nickel function as the cathode. The fiber‐shaped Ni//Bi batteries show high energy density of 43.35 Wh kg^?1 or 26.01 mWh cm^?3 and high power density of 6600 W kg^?1 or 3.96 W cm^?3 with 96% capacity retention after 10 000 cycles. They are also safe with the use of aqueous electrolyte and can be further woven into the next‐generation flexible textile‐type power system. This work provides a general and efficient strategy to develop high‐performance batteries by designing hierarchically structured electrodes.     

Ni纳米粒子掩膜用于提高GaN基LED出光率的研究

以无水乙醇为溶剂、柠檬酸为分散剂,用超声分散技术配制Ni纳米粒子分散液;将分散液用旋涂的方法在GaN基发光二极管(LED)的ITO电流扩展层上制备单层Ni纳米粒子掩膜,采用ICP(inductively coupledplasma)干法刻蚀技术在ITO层上制作出表面粗化的结构。在20 mA工作电流下,与普通GaN基LED相比,这种ITO表面粗化的GaN基LED芯片发光强度提高了30%,并且对器件的电性能影响很小。结果表明,该表面粗化技术是一种工艺简单、成本低和能有效提高LED发光效率的方法。     

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。     

High-efficiency counter electrodes using graphene hybrid with a macrocyclic nickel complex for dye-sensitized solar cells

Nanocomposites using graphene hybrid with a fully conjugated macrocyclic nickel complex were successfully prepared via a simple redox reaction of graphene oxide and an octaaza-bis-α-diimine macrocyclic nickel complex. The dye-sensitized solar cells fabricated with the graphene/macrocyclic nickel complex-based nanocomposite counter electrode reached a power conversion efficiency of 8.30%, which was higher than that of the platinum counter electrode under the same conditions. The nanocomposites exhibited excellent electrocatalytic performance for the reduction of triiodide due to the well-distributed catalytic nickel center on the graphene surface.     

Nickel–Cobalt Layered Double Hydroxide Nanosheets for High‐performance Supercapacitor Electrode Materials

A facile and novel one‐step method of growing nickel‐cobalt layered double hydroxide (Ni‐Co LDH) hybrid films with ultrathin nanosheets and porous nanostructures on nickel foam is presented using cetyltrimethylammonium bromide as nanostructure growth assisting agent but without any adscititious alkali sources and oxidants. As pseudocapacitors, the as‐obtained Ni‐Co LDH hybrid film‐based electrodes display a significantly enhanced specific capacitance (2682 F g^?1 at 3 A g^?1, based on active materials) and energy density (77.3 Wh kg^?1 at 623 W kg^?1), compared to most previously reported electrodes based on nickel‐cobalt oxides/hydroxides. Moreover, the asymmetric supercapacitor, with the Ni‐Co LDH hybrid film as the positive electrode material and porous freeze‐dried reduced graphene oxide (RGO) as the negative electrode material, exhibits an ultrahigh energy density (188 Wh kg^?1) at an average power density of 1499 W kg^?1 based on the mass of active material, which greatly exceeds the energy densities of most previously reported nickel or cobalt oxide/hydroxide‐based asymmetric supercapacitors.     

透过率实时可调的PDP屏滤光膜

利用NiOx薄膜具有优良的电致变色性能,制备了透过率可实时调整的PDP屏滤光膜以提高PDP屏的出光效率,在不同环境照度下获得更好的图像质量。采用扫描电镜(SEM)、X射线衍射仪(XRD)、分光光度计研究了采用磁控溅射法制备的NiOx薄膜中镍的含量对薄膜光电特性的影响。分析测试结果表明:溅射时随着氧分压的提高,氧化镍薄膜的镍含量明显降低;NiOx薄膜中镍原子含量为45%左右时,NiOx薄膜对可见光透过率的调节能力最强,其最高透过率与最低透过率差值达70%。     

碳酸镍沉淀过程的研究以及介孔氧化镍的制备

Nickel carbonate and nickel oxide are important inorganic fine chemicals, widely used in chemical, metallurgical, electronic and energy sources industries. The research was beginning with studying the effects of anions on precipitation process of nickel carbonate. Activity coefficient shows the effect size of the microcosmic effects between ions and solvent. Meissner's semi empirical model was applied to calculate the average activity coefficients of nickel carbonate in different electrolyte solutions at different conditions. And the conditional solubility of nickel carbonate was also calculated. The calculated results show that activity coefficients of NiCO3 in sodium sulphate solutions are less than that in sodium chloride solutions, and the solubilities in sodium sulphate solutions are larger. To improve the confidence of the calculations, Bromley's and Pitzer's models were also applied to calculate activity coefficients. The calculation results of Bromley's and Pitzer's models are very close to Meissner's results. And then experiments were carried out to measure the surface tensions, and contact angles of solutions on NiCO3 surface. According to the experiment results, the solid-liquid interface tension between NiCO3 and sodium sulphate solution is larger than that between NiCO3 and sodium chloride solution. And the tiny crystal NiCO3 has larger solubility in sodium sulphate solutions, which indicates that crystallization of NiCO3 in sodium sulphate solution is more difficult than in sodium chloride solution. The influence of SO 42- and Cl- on precipitation and crystallization process of NiCO3 was also studied based on crystal dynamics. The supersaturations at different initial concentration of reaction system were compared. Diffusion coefficients of ions were described by Glasstone's model. The diffusion coefficients of Ni2+ and CO 32- in chloride solutions are larger than those in sulphate solutions. In sulphate solutions, the diffusion coefficients and supersaturation are both less, therefore nucleation and growth rates are more slowly. Furthermore, the experiments of crystallization dynamics show that the reaction of nickel carbonate precipitation is a first order reaction while the reaction rate constant is about 0.02 min-1. Based on the theoretical analysis above, technology process of nickel carbonate precipitation was studied subsequently. The effects of nickel salt, feeding mode, controlling pH, reaction temperature and aging condition on purity, particle size, appearance of product and recovery ratio of nickel were investigated. Then using industrial nickel electrolyte solution and sodium carbonate as the raw materials, nickel carbonate product with nickel content of about 51%,average particle size of 17 μm was prepared at optimal conditions, and the recovery ratio of nickel is around 99.5%. Nickel carbonate with high purity was obtained via an innovative impurity removal process, called wash-dry-rewash-redry process. The sodium and chlorine qualitative contents of the nickel carbonate purified by the innovative method are both less than 0.01% and the sulphate content is no more than 0.1%. The mechanism of sodium and chlorine adsorption onto nickel carbonate's surface was discussed, using Stern's model of electric double layer. Moreover computational simulation technology was applied to investigate on how anions affect the crystallization of NiCO3 at atom scale. The lattice structure was relaxed before establishing crystal surfaces. The computational unit cell parameters are very close to the experimental data. Five main surfaces were studied, i.e. the (104), (100), (110), (001) and (101) surfaces. SO 42- substitutes the CO 32- on the outmost layer. Cl- adsorbs onto the surfaces and has relative weaker interaction with the surfaces. Compared with only hydrated surfaces, the growth rates of defected hydrated surfaces significantly decrease, especially for SO 24- defected ones. The (104) surface is the most stable surface and is mainly expressed in the equilibrium morphology of the resulting crystal. Finally, based on the study of nickel carbonate synthesis, nickel oxide with mesoporous structure was prepared by adding template into the nickel source and calcination. The effects of types of surfactant, dosage of surfactant, calcination temperature and calcination time on pore structure and specific surface area of nickel oxide were investigated. The results show that the surface area of the nickel oxide prepared by sodium dodecyl sulphate (SDS, anion surfactant) is much larger than those of which prepared by CTAB and octadecylamine. It is suggested that the inorganic species, basic nickel carbonate, is interacted with the template, SDS, by electrostatic attraction force. The precursor hardly has any surfactant residue after calcination. Nickel oxide with high specific surface area (>200 m2· g-1) is synthesized by adding low amount of template at the mole ratio of SDS:Ni less than 0.1:1.0. The nickel oxide has H3 type hysteresis and the pore size distribution mainly ranges from 2 nm to 10 nm. And it has good thermal stability.     

Laminated Perovskite Photovoltaics: Enabling Novel Layer Combinations and Device Architectures

High‐efficiency perovskite‐based solar cells can be fabricated via either solution‐processing or vacuum‐based thin‐film deposition. However, both approaches limit the choice of materials and the accessible device architectures, due to solvent incompatibilities or possible layer damage by vacuum techniques. To overcome these limitations, the lamination of two independently processed half‐stacks of the perovskite solar cell is presented in this work. By laminating the two half‐stacks at an elevated temperature (≈90 °C) and pressure (≈50 MPa), the polycrystalline perovskite thin‐film recrystallizes and the perovskite/charge transport layer (CTL) interface forms an intimate electrical contact. The laminated perovskite solar cells with tin oxide and nickel oxide as CTLs exhibit power conversion efficiencies of up to 14.6%. Moreover, they demonstrate long‐term and high‐temperature stability at temperatures of up to 80 °C. This freedom of design is expected to access both novel device architectures and pairs of CTLs that remain usually inaccessible.     

强电场对NiO电子结构性质的影响研究

基于平面波密度泛函理论研究了电场强度为10V?nm-1下立方结构氧化镍的电子结构性质。结果表明:立方相氧化镍在电场强度10V?nm-1下呈现导体的能带结构,价带上移到导带,态密度谱图在多个能量取得最值,局域化效应增强,费米能级附近的态密度增大为原系统的2倍多。费米能级上的载流子浓度由4 e/eV增大到15 e/eV,这源于Op、Nis、Nid态对费米面的贡献。强电场下的电子在不同量子状态之间显示了明显的转移,介电函数计算表明强电场下体系在0.32 eV附近具有最大的吸收,吸收峰峰值66.89。强电场明显调控了NiO的电学、光学和场致光吸收性能。