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. II. Lithium inorganic batteries at high discharge rates

A study was continued of the design characteristics and optimization procedures leading to an improvement of the maximum cell capacity obtainable with the high power type lithium inorganic batteries. The general relations derived for the low power type cells have been modified for use in the design of the high power type cells. A materials balance was established for the interior components of cylindrical cells made for high discharge rates.Design parameters were calculated using a computer program for several sizes of cylindrical cells. A satisfactory agreement was reached between the predicted and the realized performance of the cells built with the calculated design parameters.     

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.     

Lithium storage behaviors of PbNb2O6 in rechargeable batteries

Herein, we propose a new anode material, PbNb₂O₆, for use in lithium-ion batteries. PbNb₂O₆ can be synthesized via a simple and traditional solid-state method. The as-prepared powder exhibits an average size distribution of about 0.5 μm. When tested in a lithium-ion cell, the PbNb₂O₆ electrode can exhibit a charge capacity of 245.2 mAh g⁻¹ at 200 mA g⁻¹, and after 80 cycles, the capacity can retain a charge capacity of 181.4 mAh g⁻¹, showing 0.32% capacity fading per cycle. Furthermore, the capacity of the PbNb₂O₆ electrode is 223.1 mAh g⁻¹, even when cycled at 1000 mA g⁻¹, and a capacity of 150.7 mAh g⁻¹ is maintained up to 500 cycles. In addition, the lithiation mechanism of PbNb₂O₆ is investigated via various techniques. Interestingly, PbNb₂O₆ exhibits high capacity without the contribution of two redox couples of niobium after the initial cycles. Finally, all Results suggest that PbNb₂O₆ has potential for use as an electrode in lithium-ion batteries.     

Lithium polyacrylate as a binder for tin-cobalt-carbon negative electrodes in lithium-ion batteries

A lithium polyacrylate (Li-PAA) binder has been developed by 3M Company that is useful with electrodes comprising alloy anode materials. This binder was used to prepare electrodes made with Sn₃₀Co₃₀C₄₀ material prepared by mechanical attrition. The electrochemical performance of electrodes using Li-PAA binder was characterized and compared to those using sodium carboxymethyl cellulose (CMC) and polyvinylidene fluoride (PVDF) binders. The Sn₃₀Co₃₀C₄₀ electrodes using Li-PAA and CMC binders show much smaller irreversible capacity than the ones using PVDF binder. Poor capacity retention is observed when PVDF binder is used. By contrast, the electrodes using Li-PAA binder show excellent capacity retention for Sn₃₀Co₃₀C₄₀ materials and a specific capacity of 450 mAh/g is achieved for at least 100 cycles. The results suggest that Li-PAA is a promising binder for electrodes made from large-volume change alloy materials.     

Lithium storage performance of carbon nanotubes prepared from polyaniline for lithium-ion batteries

Carbon nanotubes with large surface area and surface nitrogen and oxygen functional groups are prepared by carbonizing and activating of polyaniline nanotubes, which is synthesized by polymerization of aniline with the self-assembly method in aqueous media. The physicochemical properties of the carbon nanotubes are characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller, elemental analyses and X-ray photoelectron spectroscopy measurements. The surface area and pore diameter are 618.9 m² g⁻¹ and 3.10 nm. The electrochemical properties of the carbon nanotubes as anode materials in lithium ion batteries are evaluated. At a current density of 100 mA g⁻¹, the activated carbon nanotube shows an enormously first discharge capacity of about 1370 mAh g⁻¹ and a charge capacity of 907 mAh g⁻¹. After 20 cycling tests, the activated carbon nanotube retains a reversible capacity of 728 mAh g⁻¹. These indicate it may be a promising candidate for an anode material for lithium secondary batteries.     

Lithium polymer batteries using the highly porous membrane filled with solvent-free polymer electrolyte

Solid polymer electrolyte supported by a microporous membrane was prepared and characterized. The polymer electrolyte was prepared by penetrating the highly conductive solvent-free polymer electrolyte based on poly(oligo [oxyethylene] oxyterephthaloyl) into the pores of the highly porous membrane. The electrochemical characteristics of the solid polymer electrolytes are presented, and we discuss the possibility of them as an electrolyte material for lithium polymer batteries.     

Lithium iron phosphate/carbon nanocomposite film cathodes for high energy lithium ion batteries

This paper reports sol–gel derived nanostructured LiFePO₄/carbon nanocomposite film cathodes exhibiting enhanced electrochemical properties and cyclic stabilities. LiFePO₄/carbon films were obtained by spreading sol on Pt coated Si wafer followed by ambient drying overnight and annealing/pyrolysis at elevated temperature in nitrogen. Uniform and crack-free LiFePO₄/carbon nanocomposite films were readily obtained and showed olivine phase as determined by means of X-Ray Diffractometry. The electrochemical characterization revealed that, at a current density of 200 mA/g (1.2 C), the nanocomposite film cathodes demonstrated an initial lithium-ion intercalation capacity of 312 mAh/g, and 218 mAh/g after 20 cycles, exceeding the theoretical storage capacity of conventional LiFePO₄ electrode. Such enhanced Li-ion intercalation performance could be attributed to the nanocomposite structure with fine crystallite size below 20 nm as well as the poor crystallinity which provides a partially open structure allowing easy mass transport and volume change associated with Li-ion intercalation. Moreover the surface defect introduced by carbon nanocoating could also effectively facilitate the charge transfer and phase transitions.     

Materials balance in primary batteries. I. Lithium inorganic cells at low discharge rates

A study has been made of the design characteristics and optimization procedures leading to an improvement in the maximum cell capacity obtainable with standard size lithium cells at low discharge rates. General relations have been derived between the cell capacity and the porosity of carbon cathode structures at various stages of cell discharge, based on a cell reaction mechanism proposed earlier. A total materials balance relation has been established for the components involved in the cell reaction in cylindrical cells made for a long range application. Design calculations have been carried out for a typical standard size cylindrical cell. A satisfactory agreement has been achieved between the predicted and the realized performance of cells built according to these calculations.     

Lithium difluoro(oxalate)borate‐based novel nanocomposite polymer electrolytes for lithium ion batteries

BACKROUND: HF formation and poor thermal stability found in commercial lithium ion batteries comprising LiPF₆ (and other salts) have hampered the replacement of LiPF₆. Therefore, a new kind of electrolyte salt is necessary to replace the one commercially available. RESULTS: A novel lithium difluoro(oxalate)borate (LiDFOB)‐based nanocomposite polymer electrolyte has been prepared in a matrix of poly[(vinylidene fluoride)‐co‐(hexafluoropropylene)] (PVdF‐HFP). The electrolyte contains ethylene carbonate and diethyl carbonate as plasticizers and nanoparticulate Sb₂O₃ as a filler. Membranes obtained by a solution casting technique were characterized by AC impedance, thermogravimetry and tensile strength measurements and morphological studies. Membranes with 5 wt% Sb₂O₃ exhibit a room‐temperature conductivity of 0.298 mS cm^?1, and are thermally stable up to ca 130 °C. Furthermore, the nanocomposite membranes show a 125% increase in mechanical stability as compared to filler‐free membranes. The structural change from α to β phases was confirmed by Raman studies. CONCLUSION: One of the important advantages of using LiDFOB lies in its bulkier DFOB anion, which also acts as solid plasticizer, thus improving the basic requirements of the electrolyte, such as mechanical and thermal stabilities, as well ionic conductivity and with a lower filler content. The overcharge tolerance of LiDFOB salt at higher temperature is also to be noted, because of the oxalate moieties. Preliminary investigations confirmed the possibility of using Sb₂O₃ nanoparticle‐filled membranes in industry in the near future. Copyright © 2008 Society of Chemical Industry     

Lithium storage performance and interfacial processes of three dimensional porous Sn–Co alloy electrodes for lithium-ion batteries

Three-dimensional porous Cu film is prepared for the first time by electroless plating. Sn–Co alloy is electrodeposited on the porous Cu film to fabricate porous Sn–Co alloy electrode. SEM images evidence that porous Sn–Co alloy electrode presents a three-dimensional porous structure. XRD results show that the Sn–Co alloy electrode comprises pure Sn and CoSn₂ phases. Electrochemical discharge/charge results show that the three-dimensional porous Sn–Co alloy electrode exhibits much better cycleability than planar Sn–Co alloy electrode, with first discharge capacity and charge capacity of 636.3 and 528.7 mAh g⁻¹, respectively. After 70th cycling, capacity retention is 83.1% with 529.5 mAh g⁻¹. The lithiation and delithiation processes during first discharge and charge were investigated by electrochemical impedance spectroscopy (EIS). EIS results together with differential capacity curves describe the process of SEI formation, charge transfer and phase transformation in the alloy electrode in the first discharge, and phase transformation during charge at delithiation potential.     

Magnesium-lead chloride batteries

The preparation of lead chloride cathodes, and their discharge in magnesium-lead chloride batteries, is described. The lead chloride blended with graphite is pasted on grids of expanded copper, using urea formaldehyde solutions as the binder. One-, five-, and fifteen-cell batteries were discharged at temperatures between –40°C and +45°C, at low current drains. For five-cell batteries energy densities in the range 10–30 Wh/lb were obtained. Mechanical properties of the cathode, so far as investigated, were excellent. The main difficulty was cathode softening during prolonged runs at high temperatures. At –40°C the battery attained working voltage in about 5 minutes; although slower than the Mg-AgCl system, the Mg-PbCl₂ system should meet many applications at this temperature.     

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.     

Recovery of Lithium Hydroxide from Spent Lithium Carbonate using Crystallizations

Abstract

Recovery of LiOH from the spent Li₂CO₃ used as absorbent for carbon dioxide in breathing apparatus was successfully explored by precipitation and crystallization. A lithium hydroxide solution was prepared by precipitation of calcium carbonate using reaction of spent Li₂CO₃ and calcium hydroxide. The effects of the operating conditions on the reaction were investigated. Conversion of calcium carbonate was about 95%. Lithium hydroxide monohydrate from lithium hydroxide solution was obtained in batch evaporative crystallization. The effect of the evaporation rate on crystal morphology was investigated. The evaporation rates were affected to control size and yield of crystals. Eventually, the purity of crystals was above 99 wt% and yield was about 80%.