Electrochemical characterization of poly(vinylidenefluoride)-zinc triflate gel polymer electrolyte and its application in solid-state zinc batteries

Gel polymer electrolyte (GPE) films comprising of poly(vinylidenefluoride), propylene carbonate, ethylene carbonate and zinc trifluoromethane sulfonate are prepared and characterized. The composition of GPE is optimized to contain minimum liquid components with a maximum specific conductivity of 3.94×10⁻³ S cm⁻¹ at (25±1) °C. A detailed investigation on the properties such as ionic conductivity, transport number, electrochemical stability window, reversibility of Zn/Zn²⁺ couple and Zn/gel electrolyte interfacial stability have been carried out. The ionic conductivity follows a VTF behaviour with an activation energy of about 0.0014 eV. Cationic transport number varies from 0.51 at 25 °C to 0.18 at 70 °C. Several cells have been assembled with GPE as the electrolyte, zinc as the anode, γ-MnO₂ as the cathode and their charge–discharge behaviour followed. Capacity values of 105, 82, 64 and 37 mAh/g of MnO₂ have been achieved at 10, 50, 100 and 200 μA/cm² discharge current densities, respectively. The discharge capacity values are almost constant for about 55 cycles for all values of current densities. Cyclic voltammetric study of MnO₂ electrode in Zn/GPE/MnO₂ cell clearly shows intercalation/deintercalation of Zn²⁺.     

Ab initio study of sodium intercalation into metal oxides

Using the full-potential linearized augmented plane wave (FP-LAPW) method, we have studied the effect of chemistry on the average intercalation voltage (AIV) caused by the Na ions intercalating into transition metal oxides. The effect of transition metal was systematically studied by varying M=Co, Ni and Mn in NaMO₂ and fixing the α-NaFeO₂ layered structure. The effect of the guest atoms into the host material is discussed in terms of the structural and electronic properties. Comparatively to Li intercalation, a significant electron transfer towards transition metal was found. This observation suggests that the transition metal contribute to the AIV determination and confirms the common assumption that intercalated electron reduces M⁴⁺ to M³⁺.     

Graphdiyne:A Versatile Material in Electrochemical Energy Conversion and Storage

Graphdiyne(GDY),which is composed of sp2-/sp-hybridized carbon atoms,has attracted increasing attention.In the structure of GDY,the existence of large triangular-like pores,well dispersed electron-rich cavities as well as a large π-conjugated structure endows GDY with a natural bandgap,fast electron/ion transport,and tunable electronic properties.These unique features make GDY competitive in areas of gas separation and capture,electronics,detectors,catalysts,biomedicine and therapy,and energy-related fields.Benefiting from the facile synthesis method,various GDY structures and GDY-based composites have been successfully prepared and show great potential in the practical application of energy storage and catalysis areas.Here,this review aims at providing a timely and comprehensive update on the preparation and application of GDY materials.The current development of GDY materials in various electrochemical fields especially in energy conversion,energy storage,and catalysis is mainly summarized.Moreover,the potential development prospects are also discussed.     

富含吡啶氮-钴活性位点的三维多级大/介孔石墨烯作为高效可逆氧电催化剂用于可充电锌-空气电池

随着能源危机的日益严峻,能源的储存和转换越来越受到人们的重视.目前人们加以开发和利用的清洁能源主要包括太阳能、风能、氢能、地热能以及电化学能等.其中,燃料电池和金属-空气电池等作为电化学器件为电化学能的开发及可持续利用提供了条件.特别是金属-空气电池以电极电位较负的金属如镁、铝、锌、铁等作负极,以空气中的氧或纯氧作正极...     

可充镁电池正极材料PTMA/石墨烯

本文制备了聚4-甲基丙烯酸-2,2,6,6-四甲基哌啶-1-氮氧自由基酯(PTMA)/石墨烯纳米复合材料,并报道了其作为可充镁电池正极材料的电化学性能.通过傅里叶变换红外(FTIR)光谱、扫描电镜(SEM)、透射电镜(TEM)表征复合材料的结构和形貌;循环伏安和恒电流充放电测试其电化学性能.粒径10 nm左右的PTMA颗粒分散在具有导电作用的石墨烯表面;在"一代"电解液Mg(AlCl2BuEt)2/四氢呋喃(THF)(0.25 mol L-1)中,22.8mA g-1充放电电流密度下,PTMA/石墨烯复合材料的起始放电容量可达到81.2 mAh g-1.研究结果表明,含有自由基的有机化合物可以作为可充镁电池的一类新型正极材料,可以进一步通过使用具有高氧化分解电压的电解液来提高其放电容量.     

Thin-Film Zinc/Manganese Dioxide Electrodes

Summary.  Thin-film electrodes allow the manufacturing of flat batteries of variable design. Their electric performance is better than that of customary cells because of a larger contact area between anode and cathode and better utilization of the electrochemically active materials. Bipolar thin-film electrodes for the rechargeable alkaline zinc/manganese dioxide system were assembled using graphite-filled plastics (high-density polyethylene and polyisobutylene). In a different approach, extremely thin electrodes were obtained using 25 μm thick foils made of non-conductive micro-porous polypropylene. The electroactive materials were electrolytically deposited into the pores of the previously metallized foil, providing the required conductive connection through the plastic matrix by themselves. Cycle behavior, cumulated capacities, and energies of batteries with up to two bipolar units were measured. At this early stage of development, batteries based on graphite-filled polymer foils showed better results with regard to storage capacity per unit area and to cycle life. Prototypes based on micro-porous polypropylene suffered from the relatively small fraction of pore volume available for the deposition of active material (about 38%) and from current collector corrosion. Received May 30, 2000. Accepted December 18, 2000     

二次锂电池聚合物正极材料研究进展

近几十年,二次锂电池作为重要的储能装置得到迅猛发展,而开发高性能的锂电池电极材料一直是电化学能源领域的研究热点之一。与传统无机正极材料相比,聚合物正极材料具有比容量高、柔软性好、廉价易得、环境友好、加工方便、可设计性强等诸多优点。本文综述了导电聚合物、共轭羰基聚合物以及含硫聚合物正极材料的结构特点、电极反应机理、电化学性能和近五年来的重大研究进展,总结了这三类聚合物电极材料的优缺点,并重点介绍了含硫聚合物电极材料中存在的问题及改进手段,最后提出了综合这三类聚合物优点的含硫共轭导电聚合物将会是该领域的研究方向。     

Charge/discharge characteristics of sulfur composite electrode at different temperature and current density in rechargeable lithium batteries

The charge/discharge characteristics of the sulfur composite cathodes were investigated at different temperatures and different current densities. The composite presented the discharge capacities of 854 and 632 mAh g⁻¹ at 60 and −20 °C, respectively, while it had the discharge capacities of 792 mAh g⁻¹ at 25 °C. The composite presented the discharge capacities of 792 and 604 mAh g⁻¹ at 55.6 and 667 mA g⁻¹, respectively, at room temperature. The results showed that the sulfur composite cathodes presented good charge/discharge characteristics between 60 and −20 °C and at a high c-rate up to 667 mA g⁻¹.     

锂镍钴复合氧化物锂离子电池正极材料的研究

本文报道了以碱式碳酸镍、碱式碳酸钴和碳酸锂为原料 ,柠檬酸为络合剂的新溶胶凝胶法制备复合锂镍钴氧化物锂离子电池正极材料 .氧气流中制备的LiNi0 .8Co0 .2 O2 具有高的循环容量 (～ 190mAhg 1)     

The effect of milling on the performance of a Mo6S8 Chevrel phase as a cathode material for rechargeable Mg batteries

In the present study, we explored how milling Mo₆S₈ Chevrel phase in inert or air atmosphere affects their electrochemical behavior as a Mg-ion insertion material for rechargeable Mg batteries. Electrochemical tools such as slow scan rate cyclic voltammograms and potentiostatic intermittent titration technique have been used in conjunction with X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy. In contrast to the deterioration observed for milling Mo₆S₈ in air, its milling under Ar results in specific capacity increase due to improved Mg-ion diffusion kinetics. It was shown that in spite of the conservation of the bulk crystallographic structure, both for air and the Ar-milled materials, they differ significantly in the average particle sizes and the degree of surface oxidation state.Dedicated to Prof. G. Horanyi on the occasion of his 70th birthday