Electrochemical performance of Zn-substituted Ni(OH)2 for alkaline rechargeable batteries

Zn-substituted Ni(OH)₂ for alkaline rechargeable batteries was prepared by a chemical coprecipitation method. The structures were characterized by X-ray diffraction and scanning electron microscopy, and the electrochemical performance, including charge–discharge behavior, the proton diffusion coefficient (D_H+), and the cycle life, was investigated in detail. The results showed that the charge–discharge potentials of Zn-substituted -Ni(OH)₂ are much higher than those of Zn-substituted -Ni(OH)₂. For a single (for 30.5–48.4% Zn content) or a single (from 0 to 9.3% Zn content) phase in the sample, the discharge potentials increase with the increase of Zn content. However, when there is an and phase mixture in the sample, the discharge potential decreases with an increase of Zn content. The D_H+ values of Zn 0% and Zn 38.1% samples measured by the current-pulse relaxation method are much lower than those of Zn 9.3% and Zn 19.6% samples. D_H+ of all the samples decreases with an increase of the depth of discharge. The effects of different Zn contents on the charge–discharge potentials of the nickel electrodes can be attributed to the differences of the electrochemical and diffusion polarization.     

Ni(OH)2纳米管的制备、表征及电化学性能

以多孔氧化铝为模板, 在不同溶液浓度下, 用化学沉积法制备了氢氧化镍纳米管. 采用XRD, SEM, TEM和HRTEM等手段, 对产物的物相、表面形貌及微结构进行了表征. 结果表明所得产物是高纯度的氢氧化镍纳米管, 外径约为180～220 nm, 管壁厚20～30 nm. 将所制备的氢氧化镍纳米管制成电极, 其电化学性能测试表明, Ni(OH)₂纳米管的中空结构特点, 能够有效地提高镍电极的充电效率、放电比容量、高倍率及高温放电性能. 机理分析表明中空结构的Ni(OH)₂纳米管对于提高碱性二次电池的综合性能有着极为重要的意义.     

Conducting poly(aniline) nanotubes and nanofibers: controlled synthesis and application in lithium/poly(aniline) rechargeable batteries

The primary aim of this work was to synthesize aligned perchloric-acid-doped poly(aniline) (HClO(4)-doped PANI) nanotubes by a simple alumina template method and to investigate their application in lithium/poly(aniline) rechargeable batteries. Powder X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) analysis were used to characterize the nanostructures obtained. The second aim addressed the preparation of HClO(4)-doped PANI microspheres and nanofibers on a large scale through a modified spraying technique, since the template synthesis has limitations in mass production. The present synthesis methods are simple and can be extended to the preparation of a broad range of one-dimensional conductive polymers. Furthermore, electrochemical measurements showed that the as-prepared HClO(4)-doped PANI nanotubes exhibit better electrode performances than their commercial counterparts because they possess more active sites, higher conductivity, and relative flexibility. This indicates that HClO(4)-doped poly(aniline) nanomaterials are promising in the application of lithium/polymer rechargeable batteries.     

Generation and growth mechanism of metal (Fe, Co, Ni) nanotube arrays.

Nanotubes composed of layered or nonlayered materials have been synthesized through various methods, among which template-based electrodeposition technology provides a versatile technique for synthesizing one-dimensional nanostructured materials. However, the growth mechanism of nanotubes using the template method is seldom clarified. Herein, we present the systematic preparation of metal nanotube arrays and put forward the growth mechanism, termed current-directed tubular growth (CDTG), for template-based electrodeposition. There are competitive growth rates for metal atoms entering the crystal lattice, that is, v( parallel) (growth rate parallel to current direction) and v( perpendicular) (growth rate perpendicular to current direction). Metal nanotubes can be obtained at v( parallel)>v( perpendicular), while nanowires can be obtained at v( parallel) approximately v( perpendicular). The as-synthesized metal (Fe, Co, Ni) nanotubes are constructed from nonlayered materials, which are of body-centered cubic iron structure, hexagonal close packed cobalt structure, and face-centered cubic nickel structure, respectively. The CDTG mechanism is expected to have applications in designing and synthesizing other metal nanotubes and even compound nanotubes via template-based electrodeposition technology.     

包覆Y(OH)3的球形Ni(OH)2的电化学性能

利用软嵌式粉末电极技术研究了Y(OH)3包覆对球形Ni(OH)2电化学性能的影响. 循环伏安结果表明, 在球形Ni(OH)2的氧化过程中存在Ni(Ⅲ)和Ni(Ⅳ)的两步氧化反应, 产生的Ni(Ⅳ)不稳定, 能分解产生NiOOH和氧气, 所以可将Ni(Ⅲ)→Ni(Ⅳ)看作副反应. Y(OH)3包覆层对Ni(OH)2氧化过程后期的副反应, 特别是Ni(Ⅲ)→Ni(Ⅳ)具有较好的抑制作用. 由包覆后的Ni(OH)2制成的模拟电池表现出很好的高温性能, 在1C充放电条件下, 当Y的摩尔分数为1.61%时, 在60 ℃时所对应的容量保持率可达到25 ℃的92.7％; 当Y的摩尔分数仅为0.55 %时, 在60 ℃时所对应的质量比容量也可达到241.3 mA·h/g.     

Lix(Al0.8Zn0.2) alloys as anode materials for rechargeable Li-ion batteries

The influence of the lithium content in the starting composition, depth of discharge, binder and electrolyte on the cycle stability was investigated. The structural changes in Li_x(Al_0.8Zn_0.2) electrodes during electrochemical lithium extraction and reinsertion were studied by in situ synchrotron diffraction. The crystal structure of the new compound Li₄Al_3.42Zn_11.58 was determined by single-crystal X-ray diffraction and can be described as combination of the CaCu₅ and MgFe₆Ge₆ structure types. The phase equilibria at 150 °C in the Li–Al–Zn system were investigated on six alloys, prepared along the lithium extraction–insertion line.     

FTIR features of lithium-iron phosphates as electrode materials for rechargeable lithium batteries

The essential structural features of lithium-metal phosphates (LMP) have been studied using FTIR spectroscopy which is a sensitive tool to probe the local environment in the solid materials. Various LMP materials where M is iron have been investigated including phospho-olivine LiFePO(4), diphosphate LiFeP(2)O(7), Nasicon-type phosphate Li(3)Fe(2)(PO(4))(3) and dihydrate FePO(4).2H(2)O. Vitreous and amorphous materials are also considered. Analysis of internal and external modes of vibration allows to distinguish between the different phases and the type of cationic environment in the framework. Results corroborate the contribution of the main factors which are responsible for the complexity of the spectra, i.e. departure from ideal symmetry, interactions between polyhedra, bridging atoms and lattice distortion.     

Fabrication of a Hierarchical Ni(OH)2@Ni3S2/Ni Foam Electrode from a Prussian Blue Analogue-Based Composite with Enhanced Electrochemical Capacitive and Electrocatalytic Properties

Developing high-efficiency, cost-effective, and durable electrodes is significant for electrochemical capacitors and electrocatalysis. Herein, a 3D bifunctional electrode consisting of nickel hydroxide nanosheets@nickel sulfide nanocubes arrays on Ni foam (Ni(OH)₂@Ni₃S₂/NF) obtained from a Prussian blue analogue-based precursor is reported. The 3D higher-order porous structure and synergistic effect of different compositions endow the electrode with large specific surface area, facile ion/electron transport path, and improved conductivity. As a result, the Ni(OH)₂@Ni₃S₂/NF electrode exhibits a high specific capacity of 211 mA h g⁻¹ at a current density of 1 A g⁻¹ and 73 % capacity retention after 5000 cycles at 5 A g⁻¹. Moreover, the Ni(OH)₂@Ni₃S₂/NF electrode has superior electrocatalytic activity for the hydrogen evolution reaction with low overpotentials of 140 and 210 mV at current densities of 10 and 100 mA cm⁻², respectively. The synthetic strategy for the unique higher-order porous structure can be extended to fabricate other composite materials for energy storage and conversion.     

High capacity and cycling stability of poly(diaminoanthraquinone) as an organic cathode for rechargeable lithium batteries

Poly(1,5‐diaminoanthraquinone) is synthesized by oxidative polymerization of diaminoanthraquinone monomers and investigated as an organic host for Li‐storage reaction. Benefiting from its high density of redox‐active, Li⁺‐associable benzoquinone groups attached to conducting polyaniline backbones, this polymer undergoes its cathodic reaction predominately through Li⁺‐insertion/extraction processes, delivering a very high reversible capacity of 285 mAh g^?1. In addition, the PDAQ polymer cathode exhibits an excellent rate capability (125 mAh g^?1 at 800 mA g^?1) and a considerable cyclability with a capacity retention of ～160 mAh g^?1 over 200 cycles, possibly serving as a sustainable, high capacity Li⁺ host cathode for Li‐ion batteries. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 235–238     

链珠状氢氧化亚镍的准电容特性及其在复合型超电容器中的应用(英)

本文采用溶胶凝聚方法制备了超细氢氧化亚镍电极材料并通过在其中掺加适量碳纳米管的方法大大提高了电极的比容量并有效改善了电极材料的阻抗特性。掺有20%碳纳米管的氢氧化亚镍复合电极材料的单电极比容量可达到320 F·g^-1。本文分别采用氢氧化亚镍/碳纳米管复合电极作为正极，活性炭作为负极，6 mol·L^-1 KOH作为电解液制备了复合型电化学电容器。采用上述方法制备的复合型电容器工作电压达到1.6 V，电容器质量比容量达到60 F·g^-1。复合型电容器能量密度达到20.11 Wh·kg^-1，最大功率密度达到8.6 kW·kg^-1,兼具高能量特性和优良的大电流放电特性。     

Encapsulation of Se/C into ultra-thin Ni(OH)2 nanosheets as cathode materials for lithium-selenium batteries

Journal of Solid State Electrochemistry - Composites consisting of selenium/carbon (Se/C) encapsulated by ultra-thin Ni(OH)2 nanosheet shell are synthesized as cathode for high-performance...     

Poly[N‐(10‐oxo‐2‐vinylanthracen‐9(10H)‐ylidene)cyanamide] as a novel cathode material for li‐organic batteries

Redox‐active polymers draw significant attention as active material in secondary batteries during the last decade. A new anthraquinone‐based redox‐active monomer was designed, which electrochemical behavior was tailored by mono‐modification of one keto group. The monomer exhibits two one‐electron redox reactions and has a low molar mass, resulting in a high theoretical capacity of 207 mAh/g. The polymerization of the monomer was optimized by variation of solvent and initiator. Moreover, the electrochemical behavior was studied using cyclic voltammetry and the polymer was used as active material in a composite electrode in lithium organic batteries. The polymer reveals a cell potential of 2.3 V and a promising capacity of 137 mAh/g. During the first 100 cycles, the capacity drops to 85% of the initial value. The influence of the charging speed on the charging/discharging properties of the batteries was further investigated. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2517–2523     

Hierarchical Porous ZnMn2O4 Hollow Nanotubes with Enhanced Lithium Storage toward Lithium‐Ion Batteries

We have purposefully developed a smart template‐engaged methodology to efficiently fabricate well‐defined ternary spinel ZnMn₂O₄ hollow nanotubes (NTs). The procedure involves coating carbon nanotubes (CNTs) with ZnMn₂O₄ nanosheets (NSs), followed by heating at high temperature in air to oxidize the CNT template. Physicochemical characterization demonstrated that the formed ZnMn₂O₄ NTs with a diameter of approximately 100 nm were composed of assembled NSs and/or nanoparticles (NPs) as building blocks and possessed numerous nanopores of several nanometers in the sidewall of the NTs. In favor of the intrinsic structural advantages, the resulting ZnMn₂O₄ NTs exhibited superior electrochemical lithium‐storage performance with a large capacity, good rate behavior, and excellent cyclability when evaluated as promising anodes for lithium‐ion batteries (LIBs). The remarkable electrochemical performance was rationally ascribed to the appealing one‐dimensional (1D) porous hollow tubular architecture with nanoscale subunits and mesopores in the sidewalls, which decreased the diffusion length for the Li⁺ ions, improved the kinetic process, and enhanced the structural integrity with sufficient void space to tolerate the volume variation during Li⁺‐ion insertion/extraction. These results highlight the promising application of 1D ZnMn₂O₄ NTs as anodes for high‐performance LIBs.     

碳纳米管负载氢氧化镍修饰电极的制备及应用

采用表面滴涂结合循环伏安法制备了碳纳米管负载氢氧化镍修饰电极(Ni(OH)2/MWNT/CCE)。研究了该修饰电极对葡萄糖的电催化氧化性能。结果表明,该修饰电极对葡萄糖具有良好的电催化氧化活性。在优化条件下,安培法检测葡萄糖的线性范围为2.0×10-7～5.7×10-4 mol.L-1(r=0.999 9,s=2 786.5μA.(mmol.L-1)-1.cm-2)和5.7×10-4～2.7×10-3 mol.L-1(r=0.999 1,s=2 005.2μA.(mmol.L-1)-1.cm-2),检出限(3sb)为8.0×10-8 mol.L-1。该法已成功用于血清中葡萄糖含量的测定。     

Co(OH)_2和Ni粉对氢氧化镍电极性能的影响

采用三角波电位扫描、X射线衍射及恒流充放电曲线法研究了在氢氧化镍电极中添加Co( OH) 2 和 Ni粉后对电极性能的影响 .结果表明 ,氢氧化镍电极中加入质量分数为 8% Co( OH) 2和 13% Ni粉时 ,电极的放电容量最高 ,电极在充放电循环过程中的膨胀最小 .     

花状β-氢氧化镍的合成和表征

本文介绍了以大环多胺(六甲基-1，4，8，11-四氮环14-4，11-二烯)的镍(Ⅱ)配合物溶液为反应物，水热水解制备出花状β- Ni(OH)₂亚微米结构，该花状β-Ni(OH)₂由几十个相互连接的纳米片构成。对中间产物的研究结果表明，随着配合物浓度的增加、反应时间的延长，产物形貌从卷曲的片状转变成纳米片组成的花状且花状结构逐渐增密。采用粉末X-射线衍射(XRD)、透射电子显微镜(TEM)和场发射扫描电子显微镜(FESEM)表征了产物，并采用Rietveld精修方法拟合了晶体结构。     

Interface‐Engineered Ni(OH)2/β‐like FeOOH Electrocatalysts for Highly Efficient and Stable Oxygen Evolution Reaction

Iron‐based (oxy)hydroxides are especially attractive electrocatalysts for the oxygen evolution reaction (OER) owing to their earth abundance, low cost, and nontoxicity. However, poor OER kinetics on the surface restricts the performance of the FeOOH electrocatalyst. Herein, a highly efficient and stable Ni(OH)₂/β‐like FeOOH electrocatalyst is obtained by facile electroactivation treatment. The activated Ni(OH)₂/β‐like FeOOH sample indicates an overpotential of 300 mV at 10 mA cm⁻² for the OER, and no clear current decay after 50 h of testing; this is comparable to the most efficient nickel‐ and cobalt‐based electrocatalysts on planar substrates. Furthermore, studies suggest that β‐like FeOOH plays a key role in remarkably enhancing the performance during the electroactivation process owing to its metastable tunnel structure with a lower barrier for interface diffusion of Ni²⁺ ions between the bilayer electrocatalyst. This study develops a new strategy to explore efficient and low‐cost electrocatalysts and deepens understanding of bilayer electrocatalysts for the OER.