Comparative studies of chloride and chloride/citrate based electrolytes for zinc–polyaniline batteries

Electrochemical behavior of zinc and thin polyaniline (PANI) polymerized from 0.1 M HCl to 0.1 M aniline on graphite electrode, in 0.2 M ZnCl₂ and 0.50 M NH₄Cl (chloride electrolyte) and with addition of 0.33 M Na-citrate (chloride/citrate electrolyte) were investigated. In the chloride/citrate comparing with chloride containing electrolyte zinc electrode shows negative shift of the open circuit potential of 130 mV, decreases of exchange current density for more than order of magnitude and increase of cathodic Tafel slope, due to the zinc ions complexation. In citrate/chloride electrolyte zinc dendrite formation were suppressed. In the range of investigated charge/discharge current densities of 0.25–1 mA cm⁻², initially obtained specific capacity was in the range of 140–85 mAh g⁻¹, respectively. In cycling regime specific capacity and columbic efficiency were affected with anodic potential limits. For anodic potential limits of 0.32 V (SCE) citrate/chloride electrolyte shows better characteristic than chloride electrolyte, due to the influence of citrate ions on negative shift of doping reaction. Increasing anodic potential limit to 0.5 V (SCE), leads to faster decrease of specific capacity in citrate/chloride than in chloride electrolyte, which was. explained by higher hydrophilic effect of citrate anions.     

Secondary aluminium-iron (III) chloride batteries with a low temperature molten salt electrolyte

Secondary aluminium-iron (III) chloride batteries using a low temperature molten salt electrolyte were constructed and tested. Discharge current densities were in the range 5 to 100 mA ( 1 to 20 mA cm^–2; C/4 to 5C); charging currents were 5mA (C/4 toC/2). Utilization of the positive electrode reactant was low due to the discharge rates and loading procedure. The mode for self discharge was dissolution of the positive electrode reactant and transport to the aluminium negative electrode where it reacted.     

Electrochemical properties of aluminium anodes for Al/air batteries with aqueous sodium chloride electrolyte

In order to develop the new anode materials for Al/air batteries, electrochemical properties of pure aluminium (99.999 %), technical grade aluminium (99.8 %) and the alloys with indium and tin, i.e. Al—0.1 % In, Al—0.2 % Sn and Al—0.1 % In—0.2 % Sn have been investigated in 2 mol dm⁻³ NaCl solution. The aluminium materials were polarized anodically in the range 20–100 mA cm⁻² for a 30 min period. During the anodic polarization variation in potential was recorded as a function of time and the simultaneous hydrogen evolution was measured. The rate of hydrogen evolution reaction was found to increase with increasing anodic polarization which is characteristic of the negative difference effect. The additional information concerning the corrosion behaviour of the tested materials was provided by light microscope imaging. The results show that the examined technical grade aluminium alloys could serve as suitable anodes for Al/air batteries containing sodium chloride electrolyte; with Al–In exhibiting the most remarkable characteristics. The addition of In as alloying component to aluminium reduces electrode polarization, decreases hydrogen evolution rate and increases the anode efficiency.     

Lithium phosphorus oxynitride thin films for rechargeable lithium batteries: Applications from thin-film batteries as micro batteries to surface modification for large-scale batteries

This article reviews the technological trends in lithium-phosphorous-oxynitride (LiPON)-film-based thin-film batteries. LiPON films have been actively used in thin-film batteries containing lithium anodes because of their excellent contact stability with lithium and the advantages offered for thin-film formation. In addition, studies that have focused on the use of LiPON films as protective layers to prevent surface deterioration of electrode materials are explored. Various studies have been conducted using LiPON films to improve the performance degradation of rechargeable lithium batteries due to a side reaction between the electrode material and the electrolyte. Finally, the technical tasks required for enhancing the utilization of LiPON films in the field of thin-film batteries or electrode surface modification are summarized.     

Materials balance in primary batteries. III. Computer aided design for standard size lithium — thionyl chloride high power cells

The study was continued of the design characteristics of high power type batteries made with the lithium/thionyl chloride system. A computer programme flow chart is presented for solving the system of equations correlating all the dimensions of cell components for any selected cell size. Various cell designs are presented for the three standard cell sizes, AA, C and D showing the effect of the geometry of the cell components on the resultant cell capacity. An optimized cell design is suggested for each particular discharge rate required. As a result of the optimization of the electrode structure, a substantial improvement in the maximum cell capacity was obtained with all three cell sizes.     

Solid-state storage batteries

Investigations were conducted to study the feasibility of a solid-state battery system for storage applications. During the development of various high energy density solid-state batteries we noted that the solid electrolyte material, LiI dispersed in large surface area Al₂O₃, has a high ionic conductivity at elevated temperatures, (for example 0.1^–1 cm^–1 at 300° C) and is suitable for high-rate storage battery applications. In solid-state battery systems both the electrodes and electrolytes are in the solid state under the operating conditions of the battery. The absence of any liquid phase makes the individual cell containers unnecessary in a multicell battery resulting in a simplified battery structure and increased package efficiency. Furthermore, no material compatibility problem is encountered in the system. As a result, the solid-state battery system has excellent charge retention characteristics and a long projected operating life. Solid-state test cells, Li-Si/LiI(Al₂O₃)/TaS₂/Ta, Li-Si/LiI(Al₂O₃/TiS₂/Ti and Li-Si/LiI(Al₂O₃)/TiS₂, Sb₂S₃, Bi were constructed and subjected to discharge-charge cycle tests at 300±10° C, at 13·7 mA cm^–2. Preliminary test results demonstrated that these solid-state battery systems are rechargeable and may be suitable for both load levelling and/or vehicle propulsion. From the considerations of material availability and cost and operational efficiencies it was concluded that the Li-Si/LiI(Al₂O₃)/TiS₂, Sb₂S₃, Bi system is most suitable among the three systems studied for the development of practical storage batteries. Preliminary design studies showed that practical energy densities of 200W h kg^–1 and 520 W h l^–1 can be realized with the Li-Si/TiS₂, Sb₂S₃, Bi storage batteries.     

Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 × 10⁻³ S cm⁻¹ and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries.     

钠离子电池研究进展

钠离子电池具有比能量高、安全性能好、价格低廉等优点,在储能领域有望成为锂离子电池的替代品。本文阐述了钠离子电池的研究现状,对钠离子电池研究的正负极材料、电解质的制备以及其电化学性能作了概述性讨论。正极材料有氧化物型、聚阴离子型;负极材料有碳基材料、钛基材料和合金负极材料等;电解液有有机溶剂电解液和凝胶聚合物电解液,并分别阐明了各种材料的优势和局限性。最后指出了这类高效钠二次电池体系有可能逐渐替代锂离子电池,并指明了现阶段发展钠离子的主要问题是不同体系材料的相互匹配。     

Materials balance in primary batteries. IV. Lithium batteries with organic electrolytes

Part IV of the study of the materials balance in primary batteries concerns the application of the optimization procedure, developed for lithium inorganic batteries, to systems using organic electrolytes. The stoichiometric characteristics of discharge reactions (k ₁ andk ₃) were defined for six different lithium battery systems and the cathode discharge characteristics (k ₂) were determined on the basis of the experimental data reported by various authors. These characteristics were then applied in the optimization procedure developed earlier to predict the maximum cell capacity obtainable at low discharge rates. The values predicted were compared with those reported by various authors; this suggests the magnitude of improvement possible with each of the systems if the present optimization procedure were applied. A good agreement was found between the predicted and the previously reported values for some systems (e.g. Li/CuO), while some other systems showed room for improvement. The optimization procedure was found inapplicable without modifications to one of the systems studied (Li/SO₂) due to the limitations in the volume available for the electrolyte.     

Materials balance in primary batteries. V. Scaling up of lithium inorganic batteries

Modified design procedures are described for large rectangular cells, since the procedures developed for small cylindrical cells [1–4] were found inapplicable in the optimization of scaled-up units. Discharge data are presented for cells several orders of magnitude larger than the standardD cell, showing a good agreement between the predicted and realized cell capacity. A remarkable increase in the energy density has been achieved with increase in the cell size, well in excess of 600Wh kg^–1 at low discharge rates. The definition of some intrinsic characteristics of the system [such as the value ofk ₃, (cm³ Ah^–1)] has been confirmed with a greater accuracy using the data obtained with these large cells.     

锂/钠离子电池过渡金属氟磷酸盐正极材料研究进展

便携式电子产品、电动汽车和储能领域的快速发展对电池能量密度的要求越来越高,正极材料是限制电池能量密度的主要因素。过渡金属氟磷酸盐（A₂MPO₄F,A=Li、Na,M=Mn、Fe、Co、Ni）是一类高比容量（~300 mA·h/g）和高能量密度（>1 000 W·h/kg）的新型正极材料。主要介绍了A₂MPO₄F的结构、合成方法与改性方面的最新进展。讨论了A₂MPO₄F所面临的主要挑战,特别是实现两电子反应所面临的困难。展望了它们的应用前景。     

钾离子电池研究进展

阐述了钾离子电池关键材料和电池技术的研究现状,特别是对普鲁士蓝类和P2、P3相层状氧化物材料作为正极材料的电化学性能及存在的问题、碳基负极材料（石墨、硬碳、软碳等）的电化学性能及钾离子脱嵌机理、当前所用电解液的优缺点等方面都进行了较为全面的讨论和分析。分析表明普鲁士蓝和非石墨材料等材料已经同时展示出较高的比容量和循环性能,而对于层状氧化物材料和石墨材料,钾离子的电化学嵌入/脱出伴随显著的体积变化和复杂的相变,同时与正负极材料具有高度相容性的电解液尚未获得。指出钾离子电池需要进一步发展其电极材料和电解液。     

Characteristics of aqueous polycarbazole batteries

The characteristics of electrochemically prepared polycarbazole (PCARB) as the cathode active material for secondary batteries are studied in aqueous electrolytes. The cell of the type Zn/Zn(ClO₄)₂/PCARB has a specific capacity of 30 Ah/kg and an energy density of 46 Wh/kg. The coulombic efficiency is about 80–90% and is dependent on the thickness of PCARB films. Cole‐Cole plots for PCARB electrodes by impedance measurements have been obtained at different oxidation potentials as a function of doping. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 145–150, 1999