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.     

电解液对全铅单液流电池电极性能的影响

研究Pb(II)和H+离子浓度对全铅单液流电池正、负电极在复合石墨基体上电化学行为的影响.结果表明,PbO2正极和Pb负极的电极过程受电化学和扩散混合控制.Pb(II)氧化沉积成PbO2时出现成核环,铅负极成核过电位小,充放电电压差远小于PbO2正极,电池极化主要来自PbO2正极.增加H+浓度有利于降低PbO2正极和Pb负极的极化,但析氧、析氢副反应和腐蚀加重.增大Pb(II)浓度有利于抑制析氧,但PbO2正极充电电压升高,充放电电压差增大.Pb(II)浓度较低时,充放电过程中PbO2沉积层少许脱落,充电电压进一步降低且更趋平稳.为此,电解液中HBF4浓度以2 mol L-1为宜,Pb(II)浓度应在0.9 mol L-1以上.     

Influence of F‐ doping on the microstructure,surface morphology and electrochemical properties of the lead dioxide electrode

The lead dioxide electrode (PbO₂) with Ti substrate and SnO₂‐Sb₂O₅ intermediate layer was doped by F^‐ ion through the potentiostatic anode co‐deposition method. The content of F in the coating can be controlled by adjusting deposition potential. The effect of F^‐ doping on the composition, surface morphology and electrochemical properties of the PbO₂ electrode was characterized by X‐ray diffraction, scanning electron microscope, X‐ray photoelectron spectroscopy and electrochemical measurement methods. The results have confirmed that the content of β‐PbO₂ increases with increasing that of F, and the doping can make the β‐PbO₂ grains become fine and the electrode surface become smooth; the specific surface areas and conductivity increase, and the initial potential of oxygen evolution shifts toward positive direction compared with the free‐doped PbO₂ electrode; the oxygen evolution potential increases with the increasing of the F^‐content in the PbO₂ film electrode. The bulk electrolysis result demonstrated that the performances of the F‐PbO₂ electrode for anodic oxidation aniline have been improved to some extent. Copyright © 2012 John Wiley & Sons, Ltd.     

Fabrication of Ga<Subscript>2</Subscript>O<Subscript>3</Subscript>–PbO<Subscript>2</Subscript> electrode and its performance in electrochemical advanced oxidation processes

Owing to its high oxygen evolution potential, PbO₂ electrode is one of the candidates for electrochemical advanced oxidation processes (EAOPs). To further improve its performance as EAOP electrode, a Ga₂O₃-doped PbO₂ electrode (Ga₂O₃–PbO₂ electrode) was fabricated by the composite plating method. SEM and XRD results showed that the crystalline in the coating of Ga₂O₃–PbO₂ electrode is more uniform and in smaller size than that in the undoped PbO₂ electrode, which provided a higher specific surface area. The electrochemical studies showed that the Ga₂O₃–PbO₂ electrode had higher oxygen evolution potential (OEP) and smaller electrode surface impedance, which is a benefit for the formation of hydroxyl radicals (·OH). The electrochemically degradation test using bromocresol green sodium (BG) solution and glucose solution as the simulated wastewater showed that the kinetics of electrochemical catalytic degradation is a pseudo-first-order reaction, and the reaction rate constant on Ga₂O₃–PbO₂ electrode was 2 times accelerated.     

Unique control of bulk reactivity by surface phenomena in a positive electrode of lithium battery

Layered LiNi_1/2Mn_1/2O₂ compound prepared by the classical coprecipitation method delivers a capacity loss upon cycling in a lithium battery, which increases upon the 5 first cycles, and then becomes less visible over the next 40 cycles. The charge–discharge polarization follows the same trend. The formation and the evolution of lithium-containing species on the grain surface of layered LiNi_1/2Mn_1/2O₂ and the interfacial charge transfer resistance have been carefully investigated upon cycling, by coupling ex situ ⁷Li MAS NMR and in situ electrochemical impedance spectroscopy. An important increase in the amount of lithiated surface species is observed during the first electrochemical cycles along with an increase of the charge transfer resistance. After reaching a maximum, both integrated intensity of the NMR signal and charge transfer resistance decrease, indicating a strong correlation between these two different surface characteristics, obtained from ex situ and in situ experiments, respectively. The evolution of surface species, probed by NMR and impedance spectroscopy, follow the same kind of variation as electrochemical parameters, demonstrating a unique control by surface phenomena of the overall electrochemical behavior of an electrode material of lithium battery.     

Surfactant effect on electrochemical-induced synthesis of α-Ni(OH)2

Nickel hydroxide films were electrosynthesized in the presence of different diluted surfactant solutions by galvanostatic electroprecipitation. Lamellar α-Ni(OH)₂ films are obtained using cationic surfactant cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecyl sulfate (SDS), and also neutral surfactant Tween® 80. The films were structurally and morphologically characterized by X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy, and electrochemically by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results evidenced that SDS remains intercalated between the lamellae of α-Ni(OH)₂. Albeit the presence of CTAB and Tween® 80, it was noticed in FTIR spectra that the surfactants did not intercalate. The morphology was affected by the presence of different surfactants. All studied surfactants displaced the oxidation potential (E _O) of Ni²⁺/Ni³⁺ process to less positive values. Also, the presence of surfactants improved the electrode charge efficiency and the charge response for the same number of moles of nickel ions deposited. The ratio of the charge and frequency change is 4.4 times bigger for films deposited with SDS when compared with pure α-Ni(OH)₂ films.     

Elektrochemische Deintercalation von Ag2PbO2

Electrochemical Deintercalation of Ag₂PbO₂ Ag₂PbO₂ was electrochemically deintercalated. The electrochemical reactions were studied in a two electrode swagelock teflon laboratory cell. A silver metal foil was used as negative electrode, and a pellet of the educt phase Ag₂PbO₂ (diameter 9 mm, thickness ca. 0.5 mm) without any graphite or binder was used as positive electrode. Silvernitrate, dissolved in acetonitrile (0.1 mol), was applied as liquid electrolyte. The electrotitration was carried out with a constant charge density of 6 μA/cm². Periods of working potential (48 h) alternated with periods of the open cell potential (3 h). The development of the cell voltage at decreasing silver content shows a continuous change of slope without any extended plateau. The Ag₂PbO₂ cell was totally charged, and the resulting product of deintercalation was proven to be binary PbO₂ in the stable α‐modification. The Rietveld evaluation of the powder diffraction data of intermediate deintercalated phases gave conclusive support to a two phase mode mechanism of deintercalation during which α‐PbO₂ was continuously separated without forming Ag_xPbO₂ solid solutions.     

Electrodeposited PbO2 thin film on Ti electrode for application in hybrid supercapacitor

PbO₂ thin films were prepared by pulse current technique on Ti substrate from Pb(NO₃)₂ plating solution. The hybrid supercapacitor was designed with PbO₂ thin film as positive electrode and activated carbon (AC) as negative electrode in the 5.3 M H₂SO₄ solution. Its electrochemical properties were determined by cyclic voltammetry (CV), charge–discharge test and electrochemical impedance spectroscopy (EIS). The results revealed that the PbO₂/AC hybrid supercapacitor exhibited large specific capacitance, high-power and stable cycle performance. In the potential range of 0.8–1.8 V, the hybrid supercapacitor can deliver a specific capacitance of 71.5 F g^?1 at a discharge current density of 200 mA g^?1(4 mA cm^?2) when the mass ratio of AC to PbO₂ was three, and after 4500 deep cycles, the specific capacitance remains at 64.4 F g^?1, or 32.2 Wh Kg^?1 in specific energy, and the capacity only fades 10% from its initial value.     

Electrodeposition of PbO2 onto Au and Ti substrates

The electrodeposition of lead dioxide (PbO₂) onto Au and Ti substrates was anodically executed at 65°C and the electrochemical characteristics and the mechanism in the PbO₂ films deposition were investigated by the using an in-situ electrochemical quartz crystal microbalance, cyclic voltammogram, and chronoamperometry experiments. An X-ray diffractometer and scanning electron microscope were also used for investigation of the formed lead dioxide films onto both substrates. Considering the experimental and theoretical mass/charge ratios, PbO₂ deposition on Au by applying constant potential was in excellent agreement with the theoretical value, while relatively higher values of the mass/charge ratio due to film hydration were found when Ti was used as substrate. Analysis of X-ray diffractometer and scanning electron microscope show different film structures on each substrate, especially the additional hydration of the lead dioxide film deposited on Ti leads to some structural effects, identified as Sky-Lotus PbO₂.     

Ozone generation on the lead dioxide electrodes in a sulfuric acid solution at potentials of 2 to 3 V

The electrochemical synthesis of ozone is studied on lead dioxide electrodes in sulfuric acid solutions. The two maximums of the current efficiency for ozone (CEO) observed at 2–3.5 V are largely due to the participation of various chemisorbed particles in the ozone synthesis. In the vicinity of the first CEO maximum at lead dioxide, ozone forms only in a discharge of water molecules with the participation of adsorbed oxygen-containing radicals. In the potential range of the second maximum, the adsorbed anion radicals, e.g., ·HSO₄ and ·SO₄, also take part in the reaction of ozone generation. At the electrode not subjected to anodic polarization, CEO is considerably higher than that on the preliminarily polarized electrode. On the basis of the experimental data, schemes for the ozone evolution at PbO₂ in sulfuric acid at 2 to 3 V are proposed.     

Embedding wasted hairs in Ti/PbO2 anode for efficient and sustainable electrochemical oxidation of organic wastewater

Despite of the hazardous risk of Pb²⁺leakage,lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential,excellent conductivity,good stability and low cost in electrochemical oxidation wastewater treatment technique.In this study,a novel Ti/PbO₂ anode was fabricated by embedding raw materials that are readily and cheaply available,i.e.,hairs.The structure-activity relationship of the new electrode was firstly revealed by material an...     

Effect of surface modification of zinc oxide on the electrochemical performances of [Ni4Al(OH)10]OH electrode

Surface modification of zinc oxide on the [Ni₄Al(OH)₁₀]OH has been performed by a chemical surface precipitation method. Inductively coupled plasma measurements show that the amount of ZnO of prepared samples increases with the increase of initial concentration of Zn²⁺ in the mother solution. Powder X-ray diffraction measurements and scanning electron microscope images show that the modification of ZnO has little effects on the lattice parameters and the particle sizes of the [Ni₄Al(OH)₁₀]OH, but does change the morphology. The charge–discharge cycles results show that the deterioration rate of discharge capacity for the electrode with ZnO is only 4.0 % after 255 cycles, which is lower than that of electrode without ZnO (8.5 %); meanwhile, the maximal numbers of exchanged electrons per nickel atom for the electrodes with ZnO are basically over 1.83, which are higher than that of the electrode without ZnO (1.73), indicating that the modification of ZnO can improve the utilization of active material. In addition, the cyclic voltammogram tests results show that the modification of ZnO not only improves electrochemical cyclic reversibility but also elevates the oxygen evolution potential. Electrochemical impedance spectroscopy measurements show that the modification of ZnO can lower the double layer capacitance and the charge transfer resistance.     

Factors Influencing Electroanalytical Measurements In Aqueous Surfactant Media

Abstract

Surfactant solutions of sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Triton X-100, have been studied for their utility as media for electroanalytical measurements. Each medium possesses a wide potential window with low background currents within which electrochemical measurements can be conducted. the potential windows at a glassy carbon electrode are +1.2 to -1.6 V for 0.1 M TEAP/SDS, 0.1 M NaCl/0.1 M SDS and 0.1 M NaCl/1.2% Triton X-100, and +0.6 to -1.6 V for 0.1 M NaCl/32 mM CTAB (V vs. Ag/AgCl (3M NaCl)). the M(II/I) redox couples of [ReCdmpe)₃]^2+/+ and [Tc(dmpe)₃]^2+/+ were used as electrochemical probes of each surfactant medium. Results are discussed In terms of the solubilization and interaction of the complexes with the micellar environment. Several factors are described which affect the general shape of the voltammograms as well as the observed values of E^o'; these include (i) the structure of the micelle as influenced by the supporting electrolyte, (ii) the electrostatic affinity of the probe complex for the micellar environment and (iii) the solubilization of each component of the redox couple in the micelle.     

Traitement électrochimique d' eaux usées chargées de phénol : étude comparative sur des électrodes de dioxyde de plomb et de platine

Electrochemical treatment of waste water containing phenol: a comparative study on lead dioxide and platinum electrodes. The objective of this work was to study the efficiency of the Pb/PbO₂ electrode for decomposing the molecule of phenol, then to compare it to a platinum model electrode. Preliminary investigations by cyclic voltammetry showed that the Pb/PbO₂ anode presents a good chemical and electrochemical stability and possesses a high oxygen overvoltage. The study also showed that the electrochemical oxidation of phenol on Pt and PbO₂ in acidic media is a complex process. Long-time electrolysis was carried out using a three potential-plateau program with different values of the oxidation potentials and different concentrations of phenol. The obtained results showed that the transformation of phenol is total on the Pb/PbO₂ anode and that it is partial on Pt. On the other hand an increase in the phenol concentration decreases the rate of its conversion on the electrodes.     

A mini-review of recent progress in lead dioxide electrocatalyst for degradation of toxic organic pollutants

Lead dioxide (PbO₂) electrocatalyst as a non-active anode have been extensively investigated in recent years with environmental objectives for the degradation of organic pollutants. Degradation of organics at the surface of the PbO₂ anode by direct and indirect oxidation mechanisms proceeds to complete mineralization under optimal conditions. However, for conventional Ti/PbO₂ anodes, low oxygen evolution potential (OEP), short service time, lead leakage, mass transfer limitation and, low active surface area are still the most important disadvantages that need much study. Development of PbO₂ electrocatalysts with a three-dimensional structure, use of innovative intermediate layers, and doping of the main electrocatalyst active layer with the aim of increasing active sites are among the new strategies for upgrading PbO₂ anodes. Focusing on articles published since 2021, this review presents current efforts by researchers to improve the electrocatalytic performance, stability and, environmental safety of PbO₂ anodes for improved degradation of environmental pollutants.     

Study on the electrocatalytic degradation of 4-chlorophenol on PbO<Subscript>2</Subscript>–ZrO<Subscript>2</Subscript> composite electrode and its electrochemical property

PbO₂–ZrO₂ composite electrodes were prepared by anodic electrodeposition in the lead nitrate solution. The electrochemical property of this electrode was studied by cyclic voltammetry, polarization curves and open-circuit potential–time curves. The results show that PbO₂–ZrO₂ composite electrodes possess higher oxygen evolution overpotential and better anti-corrosion performance than traditional PbO₂ electrodes. Electrocatalytic oxidation of 4-chlorophenol (4-CPs) in aqueous solution was studied to evaluate the applications of this electrode in environmental protection. The influence of experimental parameters on the COD removal efficiency was studied on PbO₂–ZrO₂ composite electrodes as a function of the current density, initial concentration of the 4-CPs, initial pH, supporting electrolyte concentration and electrolysis time. The results show that the 4-CPs removal efficiency in 0.1 mol L^–1 Na₂SO₄ solution containing 8 mmol L^–1 4-CPs could reach 89.2% with the current density at 200 mA cm^–2 and pH value at 6.5 after 4 h. Compared with traditional PbO₂ anodes, the PbO₂–ZrO₂ composite electrodes show higher instantaneous current efficiency with degradation of 4-CPs. The experimental results demonstrate that the PbO₂–ZrO₂ composite electrodes possess the excellent electrocatalytic activity in refractory pollutants degradation.     

MWCNTs/metal (Ni, Co, Fe) oxide nanocomposite as potential material for supercapacitors application in acidic and neutral media

Supercapacitive properties of synthesised metal oxides nanoparticles (MO where M = Ni, Co, Fe) integrated with multi-wall carbon nanotubes (MWCNT) on basal plane pyrolytic graphite electrode (BPPGE) were investigated. Successful modification of the electrode with the MWCNT-MO nanocomposite was confirmed with spectroscopic and microscopic techniques. Supercapacitive properties of the modified electrodes in sulphuric acid (H₂SO₄) and sodium sulphate (Na₂SO₄) electrolytes were investigated using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic constant current charge–discharge (CD) techniques. The specific capacitance values followed similar trend with that of the cyclic voltammetry and the electrochemical impedance experiments and are slightly lower than values obtained using the galvanostatic charge–discharge cycling. MWCNT-NiO-based electrode gave best specific capacitance of 433.8 mF?cm^?2 (ca 2,119 F?g^?1) in H₂SO₄. The electrode exhibited high electrochemical reproducibility with no significant changes over 1,000 cyclic voltammetry cycles.     

超声波处理对球形β-Ni(OH)2结构及电化学性能的影响

A method of ultrasonic treatment （UST） was first used to modify the structure and electrochemical performance of nickel hydroxide for the active material of nickel series alkaline batteries. The experimental results showed that UST was an effective method to improve the electrochemical performance of β-Ni（OH）2 such as specific discharge capacity, discharge potential, electrochemical reversibility and oxygen evolution over-potential. The results of electrochemical impedance spectroscopy, powder X-ray diffraction and particle size distribution indicated that the improvement of the performance of β-Ni（OH）2 through UST was attributed to the reduction of the charge-transfer resistance （Rt） and the diffusion impedance （Zw）, which resulted from the decrease of the crystallite and particle size and the increase of interlayer spacing. Diffusion coefficient of proton DH of ultrasonic treated β-Ni（OH）2 gained by CV tests was 1.13 × 10^-11 cm^2/s, and the average discharge specific capacity of ultrasonic treated β-Ni（OH）2 electrode was 301 mAh/g.     

Electrochemical study of intermetallic metal hydride as an anode material for Ni–MH batteries

The electrochemical behavior of Cobalt-free LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy electrode in alkaline solution was investigated using electrochemical impedance spectroscopy (EIS) at different number of charge/discharge cycles. A physicochemical model is developed in order to simulate impedance data. Kinetic parameters are obtained by fitting the electrochemical impedance spectrum performed at different number of cycles. The charge-transfer resistance decreases with increasing number of charge/discharge of cycles, whereas exchange current density and hydrogen diffusion coefficient parameters increase with increasing number of cycles. In addition, the specific surface area of LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy electrode increases due to pulverization and the formation of new active sites during charge/discharge cycling. The results of EIS measurements indicate that the performance of the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 metal hydride electrode was markedly improved with increasing number of cycles which is mainly attributed to the increase in the reaction surface area and the improvement in the electrode surface activation.     

Study on Lead Dioxide Modified Electrode and Its Application in Detection of Phenols

IntroductionOflate,thereisagreatinterestintheimprovementofleaddioxideasananodematerialforelectrosynthesis,ozonegenerationandwastewatertreatmentowingtoitshighelectri calconductivity ,largeoxygenoverpotentialandchemicalin ertness.1 5PbO2 canbeobtainedasanodicdepositsfromsolu tionsofthelow valenceions,basicstudiesontheseelec trodesaremainlyconfinedtothenucleationgrowthprocessofleaddioxidecrystallites ,ormodifiedbyothercationsinordertoimproveitsproperties.6 However,itselectrocatalyticactivi tydepe…