Effects of tetrabutylammonium hydrogen sulfate as an electrolyte additive on the electrochemical behavior of lead acid battery

Tetrabutyl ammonium hydrogen sulfate is an ion-paring reagent that has similar properties with ionic liquid. Ionic liquids belong to new branch of salts with unique properties that have ever increasing applications in electrochemical systems especially lithium-ion batteries. For the first time, the effects of tetrabutylammonium hydrogen sulfate (TBAHS) as an electrolyte additive in battery’s electrolyte was studied on the hydrogen and oxygen evolution overpotential and anodic layer formation on lead–antimony–tin grid alloy of lead acid battery by using cyclic voltammetry and linear sweep voltammetry in aqueous sulfuric acid solution. The grid surface morphology after cyclic redox reaction was studied by using scanning electron microscopy. The results show that, by increasing TBAHS concentration in the electrolyte, hydrogen and oxygen overpotential were increased, and so the crystalline structure of PbSO₄ layer changed. Also, cyclic voltammogram on carbon–PbO paste electrode shows that with presence of TBAHS in the electrolyte, oxidation and reduction peak current intensively increased and peak potential for oxidation and reduction of PbO were dependent on TBAHS concentration.     

The effect of Pb and other elements found in recycled polypropylene on the manufacturing of lead-acid battery cases

Polypropylene (PP) is one of the most common plastics used in the manufacturing of lead-acid battery cases, where the recycling of the material has become common practice, being both economically viable and environmentally friendly. During the recycling process, the various components of the spent battery are separated, where the crushed battery case is washed in order to remove any excess acid and lead-containing particles. The plastic components are subsequently melted and extruded into pellets that are then blended with virgin material to injection mold new battery cases and lids. This study showed that a significant amount of lead-containing particles in the form of lead dioxide and lead sulfate remain in the recycled plastic, and are evenly distributed throughout the polymer matrix. TEM studies showed that the particles are less than 1 μm in size and X-ray diffraction analysis of ashed recycled PP samples showed the presence, amongst others, of talc, calcium carbonate, rutile and iron oxide. These compounds come from a range of fillers, flame-retardants, colorants and impurities that originated from the various original battery cases that were recycled. The study showed that modern X-ray fluorescence (XRF) analysis is a quick and reliable method to quantify the amount of the elements found in the plastic and that the concentration of Pb in the plastic can be used as a type of “tracer” to determine the amount of recycled PP used in the manufacturing of a particular battery case. The study also showed that there is possible environmental contamination, in particular with Pb and Br contained in recycled PP during the injection molding process and the burning of the plastic. The Pb- and Br-containing particles are small enough to become air-borne during the burning process of the plastic, resulting in them being part of the soot and other hydrocarbon oils that are emitted. No Pb was observed in the gases emitted during simulated low-temperature injection molding conditions; however, a significant amount of Br was detected in the gases at the lower temperatures. Clear environmental waste classification of the battery case plastic should be done before its final incineration where the amount of trace metals present and its possible contamination to the environment should be considered. Care should also be taken for machine operators who work with the recycled plastic, that no excessive exposure to the halogenated compounds is experienced.     

Effect of surfactant and mineral additive on the efficiency of lead-acid battery positive active material

The effect of Sodium tripolyphosphate (STPP) and mineral additive on the performance of the lead-acid battery positive plate has been investigated. The addition of alumina-silicate to the positive paste and STPP to the electrolyte modifies the shape and size of PbO₂ crystals and improves the utilization of the positive active material (PAM). The electrochemical performance of the positive active material was determined using galvanostatic discharge and electrochemical impedance spectroscopy (EIS). The crystal structure and morphology of the PAM (PbO₂) were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The water content of the PAM was calculated using Thermogravimetric analysis (TGA) technique. The results showed that the addition of surfactant and mineral additive changes the morphology and the crystallite size of the PAM. We observe a remarkable improvement of the discharge capacity of the PAM when the surfactant (STPP) is added in the electrolyte. The discharge capacity increases with the decrease of the crystallite size and the charge transfer resistance R_ct of the PAM. This shows that the addition of mineral additive and the surfactant together improves the electrical performance of lead-acid battery.     

Effect of surface fluorination on the electrochemical behavior of petroleum cokes for lithium ion battery

Surface structure change and electrochemical behavior of fluorinated petroleum coke samples (petroleum cokes: petroleum coke and those heat-treated at 1860 °C, 2300 °C and 2800 °C, abbreviated to PC, PC1860, PC2300 and PC2800, respectively) have been investigated. Surface oxygen of petroleum coke was decreased by the fluorination using elemental fluorine. Raman and EPR spectroscopies revealed that surface fluorination increased surface disorder and lattice defects. ¹⁹F NMR spectrum suggests that distribution of fluorine atoms in PC fluorinated 300 °C was similar to that in graphite fluoride with covalent CF bonds. Surface areas of fluorinated petroleum cokes were nearly the same as those of non-fluorinated ones or only slightly increased by fluorination, except PC fluorinated at 300 °C. It is noted that first coulombic efficiencies of PC2300 and PC2800 were highly increased to 80-84% by the fluorination at 300 °C. These values of 80-84% were 12-18% higher than those of non-fluorinated PC2300 and PC2800.     

Electrochemical properties of electrolyte for lead fluoroborate redox flow battery prepared with recovered lead

The electrochemical properties of electrolyte for soluble lead flow battery(SLFB) are a key factor for the improvement of its performance. Pb(BF₄)₂ in which Pb²⁺ ions are highly soluble is cheaper and more stable than conventional Pb(CH₃SO₃)₂. This paper presents the electrochemical properties of HBF₄ and Pb(BF₄)₂ prepared with recovered lead for the electrolytes of SLFB. The density difference of reagent grade and recovered lead electrolytes is less than 0.05 g/cm³ and their viscosities increase up to 132 %, 120 %, respectively when concentration of Pb(BF₄)₂ changes from zero to 2.0 mol·dm⁻³. The conductivity of 1.5 mol·dm⁻³ electrolyte prepared with recovered lead has a peak when concentration of HBF₄ is less than 1.0 mol·dm⁻³. The results of cyclic voltammetry, linear sweep voltammetry and constant current charge/discharge test showed that impurities of recovered lead exert insignificant influences on the Pb²⁺/Pb and Pb²⁺/PbO₂ reactions. These results are promising to apply recovered lead to SLFB.     

Thermal characterization of tetrabasic lead sulfate used in the lead acid battery technology

The thermal production of 4PbO·PbSO₄ was comprehensively studied and characterized for two syntheses routes, i.e. either heating 3PbO·PbSO₄·H₂O, or a mixture of 4PbO:PbSO₄, in air to about 700 °C. In the 3PbO·PbSO₄·H₂O approach, the formation of an intermediate amorphous phase occurred at around 210 °C with the loss of H₂O from the hydrated structure. Formation of 4PbO·PbSO₄ initiated at around 270 °C with predominantly 4PbO·PbSO₄ and 13% residual PbO·PbSO₄ existing at 700 °C. With the synthesis route of mixing a stoichiometric ratio of 4PbO with PbSO₄, an intermediate phase of PbO·PbSO₄ formed at around 300 °C, before the 4PbO·PbSO₄ phase started to form at around 500 °C. Upon further heating, 4PbO·PbSO₄ was the predominant phase with 8% of PbO·PbSO₄ remaining. Both samples decomposed upon further heating to 850 °C. Powder neutron diffraction studies of the final 4PbO·PbSO₄ products from the two different synthesis routes showed similar crystallographic unit cell lattice parameters with slight differences in the PbO:PbSO₄ contents. This could possibly be linked to differences observed in the microscopic crystallite shapes from the two synthesis routes.     

Application of surface electrochemical passivation of lead-antimony alloy for a simple and rapid electrochemical determination of antimony content

A simple, rapid and selective electrochemical method is proposed as a novel and powerful analytical technique for the solid phase determination of less than 4% antimony in lead-antimony alloys without any separation and chemical pretreatment. The proposed method is based on the surface antimony oxidation of Pb/Sb alloy to Sb(III) at the thin oxide layer of PbSO₄/PbO that is formed by oxidation of Pb and using linear sweep voltammetric (LSV) technique. Determination was carried out in concentrate H₂SO₄ solution. The influence of reagent concentration and variable parameters was studied. Antimony of Pb/Sb alloys can be determined in the range of 0.0056–4.00% with a detection limit of 0.0045% and maximum relative standard deviation of 4.26%. This method was applied for the determination of Sb in lead/acid battery grids satisfactory.     

Optimization of lead adsorption from lead-acid battery recycling unit wastewater using H2SO4 modified activated carbon

During the recycling of exhausted lead-acid battery, large amount of wastewater is discharged, which contains the toxic Pb(II) ions in high concentration. In this study, the granular activated carbon after modification with sulfuric acid has been used to remove the Pb(II) ions from this wastewater. Adsorbents were characterized using Fourier Transform Infrared, Scanning Electron Microscope, and X-Ray Diffraction analyzer. Taguchi orthogonal L16 array (4^3) was used for batch adsorption study with four levels of three factors initial pH, adsorbent dose, and contact time. Optimum level of parameters was fourty + nd pH 4.5, time 240 min, and dose 0.05 g/50 mL using signal-to-noise ratio (larger-the-better response). Analysis of variance technique was used to signify the adsorption experiment model. The effect of parameters on uptake capacity of adsorbent has been evaluated. Maximum adsorbent capacity for Pb(II) uptake from wastewater of battery recycling unit was found 8.19 mg/g after modification with sulfuric acid. To further understand the mechanism of adsorption, isotherm and kinetic studies were carried out. Experimental data were well fitted with Langmuir isotherm model and pseudo-second-order kinetic model. The study suggested that H₂SO₄ modified granular activated carbon can be potentially used to remove Pb(II) from lead-acid battery recycle wastewater.     

铈对铅钙锡合金在硫酸溶液中阳极行为的影响

应用循环伏安法研究了Pb - 0 .5at %Ca - 1 .5at %Sn和含Ce的Pb - 0 .5at%Ca - 1 .5at%Sn合金电极在 4.5mol·dm- 3H2 SO4溶液中和 0 .6～ 1 .4V(vs .Hg/Hg2 SO4电极 )电位范围内的电化学特性 ,并采用线性电位扫描法和交流伏安法分别研究了上述合金在相同溶液中以 0 .9V(vs .Hg/Hg2 SO4电极 )生长的阳极Pb(Ⅱ )膜增长率和膜的阻抗实数部分 (Z’)变化 .结果表明 ,在铅合金中添加Ce对阳极Pb(Ⅱ )膜的生长有显著的抑制作用并降低铅阳极膜的Z’ .以上述两种合金作为正极板栅制作的铅蓄电池 ,含Ce的Pb Ca Sn合金的深充放循环性能明显优于Pb Ca Sn合金 .     

Crystal structure and electrochemical properties of rare earth non-stoichiometric AB5-type alloy as negative electrode material in Ni-MH battery

The La_0.85Mg_xNi_4.5Co_0.35Al_0.15 (0.05?x?0.35) system compounds have been prepared by arc melting method under Ar atmosphere. X-ray diffraction (XRD) analysis reveals that the as-prepared alloys have different lattice parameters and cell volumes. The electrochemical properties of these alloys have been studied through the charge-discharge recycle testing at different temperatures and discharge currents. It is found that the La_0.85Mg_0.25Ni_4.5Co_0.35Al_0.15 alloy electrode is capable of performing high-rate discharge. Moreover, it has very excellent electrochemical properties as negative electrode materials in Ni-MH battery at low temperature, even at −40°C.     

Effect of platinum on the photoelectrochemical behavior of lead oxide thin film

The effect of Pt on the photoelectrochemical behavior of lead oxide prepared from anodization of Pb-Pt alloy containing various concentrations of Pt has been studied. It is observed that, while Pt reduces the resistivity of the oxide film, it also reduces the photoconversion efficiency of the photoelectrochemical cell prepared from this material. The reason for this low efficiency is discussed. Received: 19 November 1997 / Accepted: 9 March 1998     

pH对溶胶-凝胶法制备的锂离子电池正极材料磷酸铁锂的形貌及电化学性能的影响

采用溶胶-凝胶法制备了锂离子电池正极材料LiFePO_4;探讨了pH对磷酸铁锂的形貌及电化学性能的影响.结果表明,随着pH的升高,LiFePO_4的粒径减小,粒径分布变窄,电化学性能提高.在不同pH下制备的LiFePO_4材料以0.2C的倍率放电,首次放电比容量分别为126.8mAh/g、132.4mAh/g、145.6mAh/g.     

Effects of heat-treatment on electrochemical behavior

The polyacenic semiconductive (PAS) material is a typical amorphous carbon prepared by pyrolysis of phenolformaldehyde resin, and is actually utilized as anode of high-capacity rechargeable batteries. In this work, change in the discharging amount of Li⁺ before and after heat-treatment of the PAS electrodes at the various doping level was examined in detail. As a result, the doped Li can be classified into two types: (i) heat-resistant Li-dopant (or Li-dopant with high diffusion coefficient) and (ii)heat-fragile Li-dopant (or Li-dopant with low diffusion coefficient). The latter Li-dopants are generated above the doping level of 30% ([Li]/[C]→0.3) and is considered to be the origin of high-capacity of PAS anode compared with that of graphite anode. This aspect is also supported by the ESR, ⁷Li-NMR, and XPS observation results. This revised version was published online in August 2006 with corrections to the Cover Date.     

Surface fluorination and electrochemical behavior of petroleum cokes graphitized at medium and high temperatures for secondary lithium battery

The surface structure and electrochemical performance have been investigated of petroleum cokes heat-treated at 2100 and 2600 °C (abbreviated to PC2100 and PC2600) and those fluorinated by elemental fluorine at 200 and 300 °C. XPS study indicated that surface fluorine was covalently bonded to carbon and surface fluorine contents were in the range of 4.9-17.8 at.%. Surface oxygen was reduced by fluorination. BET surface areas were nearly the same before and after fluorination. Fluorination enhanced D-band intensity in two Raman shifts observed at 1580 cm⁻¹ (G-band) and 1360 cm⁻¹ (D-band), indicating the increase in the surface disordering. At a high current density of 150 mA/g, the capacity increase was observed for PC2100 fluorinated at 200 °C and for PC2600 fluorinated at 200 and 300 °C. The most interesting result was the increase in first coulombic efficiencies by surface fluorination. First columbic efficiencies for PC2600 fluorinated at 300 °C were increased by 12.1% at 60 mA/g and by 25.8% at 150 mA/g, respectively. The impedance measurements showed that the resistances of surface films on carbon electrodes were increased by fluorination, however, the charge transfer resistances were decreased by 12.3% for PC2100 fluorinated at 200 °C, and by 27.5 and 6.4% for PC2600 fluorinated at 200 and 300 °C, respectively. The reduction of the charge transfer resistances was consistent with increase in the charge capacities for PC2100 fluorinated at 200 °C and PC2600 fluorinated at 200 and 300 °C.     

Effect of acridine hydrochloride on the temperature dependence of dissolution of Sn70In alloy

The effects of temperature, potential, and addition of acridine hydrochloride on the anodic dissolution of SnIn alloy containing 70% In in a chloride-containing solution were studied by chronoamperometry. The processes of In dissolution limited by solid and liquid state diffusions and also those associated with a phase rearrangement and enhancement of the alloy surface were considered. Translated fromIzvistiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1950–1954, October, 1998.     

Influence of acidic ionic liquids as an electrolyte additive on the electrochemical and corrosion behaviors of lead-acid battery

The aim of this study is to introduce the application of some acidic ionic liquids (ILs) as an electrolyte additive in lead-acid batteries. A family of alkylammonium hydrogen sulfate ILs, which are different in the number of alkyl chain, is investigated with the aim to compare their effects on the electrochemical behavior of Pb–Sb–Sn alloy in sulfuric acid solution. The hydrogen and oxygen gas evolution potential and anodic layer characteristics were investigated employing cyclic and linear sweep voltammetric methods. The morphological changes of the PbSO₄ layer that formed on the electrode surface were confirmed using scanning electron microscopy. Also, potentiodynamic polarization curves, electrochemical impedance spectroscopy, and an equivalent circuit analysis were used to evaluate the corrosion behaviors of the Pb–Sb–Sn alloy in the presence of ILs. The obtained results indicate that hydrogen and oxygen evolution overpotential of lead–antimony–tin alloy increases in the solution containing IL and mainly depends on the number of alkyl chain in alkylammonium cation. It is clearly observed that the morphology of PbSO₄ layer changes under the influence of ILs. The corrosion studies show an increase in corrosion resistance of lead alloy in the presence of some ILs. Also, the electrochemical effects of ILs in conversion of PbSO₄ to PbO₂ and vice versa were investigated by carbon-PbO paste electrode. Cyclic voltammogram of carbon-PbO electrode shows that in the presence of ILs, oxidation and reduction peak currents increase, while reversibility decreases.     

Study on stabilities and electrochemical behavior of V(V) electrolyte with acid additives for vanadium redox flow battery

Several acid compounds have been employed as additives of the V(V) electrolyte for vanadium redox flow battery (VRB) to improve its stability and electrochemical activity. Stability of the V(V) electrolyte with and without additives was investigated with ex-situ heating/cooling treatment at a wide temperature range of −5 °C to 60 °C. It was observed that methanesulfonic acid, boric acid, hydrochloric acid, trifluoroacetic acid, polyacrylic acid, oxalic acid, methacrylic acid and phosphotungstic acid could improve the stability of the V(V) electrolyte at a certain range of temperature. Their electrochemical behaviors in the V(V) electrolyte were further studied by cyclic voltammetry (CV), steady state polarization and electrochemical impedance spectroscopy (EIS). The results showed that the electrochemical activity, including the reversibility of electrode reaction, the diffusivity of V(V) species, the polarization resistance and the flexibility of charge transfer for the V(V) electrolyte with these additives were all improved compared with the pristine solution.     

Effect of benzaldehyde derivatives on the rate of hydrogen evolution in a sealed lead-acid battery

The influence exerted by a number of benzaldehyde derivatives on the rate of hydrogen evolution from a lead-acid battery was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 9, 2004, pp. 1467–1471.Original Russian Text Copyright © 2004 by Kamenev, Kiselevich, Ostapenko, Varypaev.