The behaviour of lead dioxide electrodes in acidic sulfate electrolytes

1981 ◽  
Vol 34 (2) ◽  
pp. 247 ◽  
Author(s):  
DB Matthews ◽  
MA Habib ◽  
SPS Badwal
Keyword(s):  
Sulfuric Acid ◽  
Ammonium Sulfate ◽  
Discharge Capacity ◽  
Lead Dioxide ◽  
Active Material ◽  
Cycle Number ◽  
Vehicle Propulsion ◽  
Rate Of Increase ◽  
Pbo2 Electrode ◽  
Acidic Sulfate

The variation of discharge capacity during charge-discharge cycling of a PbO2 electrode, prepared by pressing PbO2 powder onto a smooth lead disc, in sulfuric acid and acidic ammonium sulfate solutions of various concentrations was investigated by the potentiodynamic technique. The discharge capacity was found to increase with cycle number in 0.05-4.3 H2SO4; this was explained in terms of the increase in porosity of the electrode with cycling. The rate of increase was highest in a 1 mol dm-3 solution. The presence of ammonium sulfate decreased the discharge capacity at all concentrations of sulfuric acid except for the 1 mol dm-3 solution where it caused a small increase in capacity. The morphology of the electrode was studied by scanning electron microscopy and the results are correlated with the discharge capacity. These results indicated that a solution of composition 0.5 mol dm-3 ammonium sulfate and 1.0 mol dm-3 sulfuric acid will produce a greater utilization of positive plate active material (PbO2) during discharge. This result, taken together with the results of earlier studies on lead in acidic sulfate electrolytes, points to the possibility of a Pb/H2SO4,/PbO2 battery for electric-vehicle propulsion.

The Lead Dioxide Anode. II. The Kinetics and Participation of the Lead Dioxide Electrode in Electrochemical Oxidation Reactions in Sulfuric Acid

1989 ◽  
Vol 42 (9) ◽  
pp. 1527 ◽  
Author(s):  
TH Randle ◽  
AT Kuhn
Keyword(s):  
Sulfuric Acid ◽  
Electrochemical Oxidation ◽  
Maximum Rate ◽  
Lead Dioxide ◽  
Chemical Oxidation ◽  
Oxidation Reactions ◽  
Electrochemical Regeneration ◽  
Electrode Surfaces ◽  
Lead Dioxide Electrode ◽  
Lead Dioxide Anode

Lead dioxide is a strong oxidizer in sulfuric acid, consequently electrochemical oxidation of solution species at a lead dioxide anode may occur by a two-step, C-E process (chemical oxidation of solution species by PbO2 followed by electrochemical regeneration of the reduced lead dioxide surface). The maximum rate of each step has been determined in sulfuric acid for specified lead dioxide surfaces and compared with the rates observed for the electrochemical oxidation of cerium(III) and manganese(II) on the same electrode surfaces. While the rate of electrochemical oxidation of a partially reduced PbO2 surface may be sufficient to support the observed rates of CeIII and MnII oxidation at the lead dioxide anode, the rate of chemical reaction between PbO2 and the reducing species is not. Hence it is concluded that the lead dioxide electrode functions as a simple, 'inert' electron-transfer agent during the electrochemical oxidation of CellI and MnII in sulfuric acid. In general, it will most probably be the rate of the chemical step which determines the feasibility or otherwise of the C-E mechanism.

scholarly journals Photochemical organonitrate formation in wet aerosols

2016 ◽  
Vol 16 (19) ◽  
pp. 12631-12647 ◽  
Author(s):  
Yong Bin Lim ◽  
Hwajin Kim ◽  
Jin Young Kim ◽  
Barbara J. Turpin
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Ammonium Sulfate ◽  
Ultra Performance Liquid Chromatography ◽  
Oxidation Products ◽  
Peroxy Radicals ◽  
Flight Mass Spectrometry ◽  
Tartaric Acids ◽  
Fine Aerosol ◽  
Dilute Aqueous Solutions

Abstract. Water is the most abundant component of atmospheric fine aerosol. However, despite rapid progress, multiphase chemistry involving wet aerosols is still poorly understood. In this work, we report results from smog chamber photooxidation of glyoxal- and OH-containing ammonium sulfate or sulfuric acid particles in the presence of NOx and O3 at high and low relative humidity. Particles were analyzed using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). During the 3 h irradiation, OH oxidation products of glyoxal that are also produced in dilute aqueous solutions (e.g., oxalic acids and tartaric acids) were formed in both ammonium sulfate (AS) aerosols and sulfuric acid (SA) aerosols. However, the major products were organonitrogens (CHNO), organosulfates (CHOS), and organonitrogen sulfates (CHNOS). These were also the dominant products formed in the dark chamber, indicating non-radical formation. In the humid chamber (> 70 % relative humidity, RH), two main products for both AS and SA aerosols were organonitrates, which appeared at m ∕ z− 147 and 226. They were formed in the aqueous phase via non-radical reactions of glyoxal and nitric acid, and their formation was enhanced by photochemistry because of the photochemical formation of nitric acid via reactions of peroxy radicals, NOx and OH during the irradiation.

Silicon Quantum Dots-Carbon Nanotube Composite as Anode Material for Lithium Ion Battery

2013 ◽  
Vol 1540 ◽  
Author(s):  
Lanlan Zhong ◽  
Andi Xie ◽  
Lorenzo Mangolini
Keyword(s):  
Discharge Capacity ◽  
Silicon Nanoparticles ◽  
Electrode Materials ◽  
Active Material ◽  
Weight Ratio ◽  
Lithium Ion ◽  
Aliphatic Chain ◽  
Deposition Technique ◽  
Weight Content ◽  
Vapor Deposition Technique

ABSTRACTSilicon is a very promising material for anodes of lithium ion batteries. It exhibits a high theoretical capacity of 3579 mAh/g. However, during the lithiation and de-lithiation, silicon materials experience up to a 300% volume change, leading to poor cyclability [1-2]. Research shows that reducing the silicon particle size can mitigate this problem. Carbon nanotubes (CNTs) function well as electrode materials in electrolytic cells because of their high electrical conductivity and surface area. In this work, we combine silicon nanoparticles (Si NPs) and CNTs as anode materials. Si NPs are generated using a plasma-enhanced chemical vapor deposition technique and their surface is modified with a 12-carbon long aliphatic chain to impart solubility in non-polar solvents. They are applied onto a nanotube-based layer using a wet-phase deposition technique. SEM and TEM analysis confirm that they form a conformal coating onto the nanotube surface. The CNTs - Si NPs composite active material is tested in half-cells where lithium foil acts as counter electrode. We have achieved an average of 810 mAh/g discharge capacity for composites with a CNTs to Si NPs weight ratio of 1:1. We expect to be able to increase the discharge capacity by increasing the Si NPs weight content.

scholarly journals The Novel Strategy for Increasing the Efficiency and Yield of the Bipolar Membrane Electrodialysis by the Double Conjugate Salts Stress

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 343 ◽  
Author(s):  
Dong Wang ◽  
Wenqiao Meng ◽  
Yunna Lei ◽  
Chunxu Li ◽  
Jiaji Cheng ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Cation Exchange ◽  
Ammonium Sulfate ◽  
Sodium Sulfate ◽  
Sulfate Solution ◽  
Anion Exchange Membrane ◽  
Ammonium Sulfate Solution ◽  
Bipolar Membrane ◽  
Bipolar Membrane Electrodialysis ◽  
Exchange Membrane

To improve sulfuric acid recovery from sodium sulfate wastewater, a lab-scale bipolar membrane electrodialysis (BMED) process was used for the treatment of simulated sodium sulfate wastewater. In order to increase the concentration of sulfuric acid (H2SO4) generated during the process, a certain concentration of ammonium sulfate solution was added into the feed compartment. To study the influencing factors of sulfuric acid yield, we prepared different concentrations of ammonium sulfate solution, different feed solution volumes, and different membrane configurations in this experiment. As it can be seen from the results, when adding 8% (NH4)2SO4 into 15% Na2SO4 under the experimental conditions where the current density was 50 mA/cm2, the concentration of H2SO4 increased from 0.89 to 1.215 mol/L, and the current efficiency and energy consumption could be up to 60.12% and 2.59 kWh/kg, respectively. Furthermore, with the increase of the volume of the feed compartment, the concentration of H2SO4 also increased. At the same time, the configuration also affects the final concentration of the sulfuric acid; in the BP-A-C-BP (“BP” means bipolar membrane, “A” means anion exchange membrane, and “C” means cation exchange membrane; “BP-A-C-BP” means that two bipolar membranes, an anion exchange membrane, and a cation exchange membrane are alternately arranged to form a repeating unit of the membrane stack) configuration, a higher H2SO4 concentration was generated and less energy was consumed. The results show that the addition of the double conjugate salt is an effective method to increase the concentration of acid produced in the BMED process.

scholarly journals Sustainable Hydrometallurgical Recovery of Valuable Elements from Spent Nickel–Metal Hydride HEV Batteries

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1062 ◽  
Author(s):  
Kivanc Korkmaz ◽  
Mahmood Alemrajabi ◽  
Åke Rasmuson ◽  
Kerstin Forsberg
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Hybrid Electric Vehicle ◽  
Active Material ◽  
Sulfuric Acid Concentration ◽  
Dissolution Kinetics ◽  
Leach Solution ◽  
Nickel Metal ◽  
Acid Leach ◽  
Kinetics Of

In the present study, the recovery of valuable metals from a Panasonic Prismatic Module 6.5 Ah NiMH 7.2 V plastic casing hybrid electric vehicle (HEV) battery has been investigated, processing the anode and cathode electrodes separately. The study focuses on the recovery of the most valuable compounds, i.e., nickel, cobalt and rare earth elements (REE). Most of the REE (La, Ce, Nd, Pr and Y) were found in the anode active material (33% by mass), whereas only a small amount of Y was found in the cathode material. The electrodes were leached in sulfuric acid and in hydrochloric acid, respectively, under different conditions. The results indicated that the dissolution kinetics of nickel could be slow as a result of slow dissolution kinetics of nickel oxide. At leaching in sulfuric acid, light rare earths were found to reprecipitate increasingly with increasing temperature and sulfuric acid concentration. Following the leaching, the separation of REE from the sulfuric acid leach liquor by precipitation as NaREE (SO4)2·H2O and from the hydrochloric acid leach solution as REE2(C2O4)3·xH2O were investigated. By adding sodium ions, the REE could be precipitated as NaREE (SO4)2·H2O with little loss of Co and Ni. By using a stoichiometric oxalic acid excess of 300%, the REE could be precipitated as oxalates while avoiding nickel and cobalt co-precipitation. By using nanofiltration it was possible to recover hydrochloric acid after leaching the anode material.

Modelling of sulfuric acid and ammonium sulfate aerosol formation in the aerrea2 reactor

1998 ◽  
Vol 29 ◽  
pp. S87-S88
Author(s):  
Martin Wilck ◽  
Frank Stratmann ◽  
Lars Asbjørn Larsen ◽  
Rita Van Dingenen ◽  
Frank Raes
Keyword(s):  
Sulfuric Acid ◽  
Ammonium Sulfate ◽  
Sulfate Aerosol ◽  
Aerosol Formation
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