Positive Electrode In Lead-acid Battery Research Articles

Synthesis of Nafion-reduced graphene oxide/polyaniline as novel positive electrode additives for high performance lead-acid batteries

Graphite oxide (GO) has rich oxygen-containing functional groups and active site, which can significantly improve the utilization of its active substances as a positive electrode additive for lead-acid batteries. However, during the charging and discharging cycle, some GO is oxidized and decomposed, resulting in a weakened electrical connection between the positive active material particles and a decrease in battery performance. To enhance the functionality and efficacy of GO, this study initially synthesized a precursor of Nafion-reduced graphene oxide/polyaniline (NGP). Subsequently, layered NGP (HNGP) composite materials were prepared using polystyrene spheres as sacrificial templates. These HNGP composites were employed as additives for the positive electrodes of lead-acid batteries. The rate performance tests conducted at 0.05, 0.1, 0.2, 0.5, and 1 C revealed that the discharge specific capacities of the control sample and the positive electrode of the lead-acid battery incorporating the novel additive were 104.76, 77.28, 74.59, 64.23, 51.22 mAh g−1 and 187.37, 168.56, 117.44, 95.65, 83.78 mAh g−1, respectively. The remarkable conductivity and intricate porous structure of HNGP expedite the migration of positive electrode electrons and the diffusion of ions in the electrolyte within the electrode plate, thereby augmenting reaction kinetics and substantially elevating the discharge capacity and rate performance of the battery.

The Evolution Tracking of Tribasic Lead Sulfates Features in Lead-Acid Battery Positive Electrode using Design of Experiments

The positive electrode of lead-acid battery (LAB) still limits battery performance. Several approaches have been attempted to remedy this problem either with the incorporation of additives or by electrode modification. However initial performance and cycling of the LAB is determined by the kind and content of basic lead sulfate in the paste. As a result, it is critical to comprehend the mechanisms that take place during paste manufacture and how they affect the properties of the active materials. In this work, the experimental design methodology was applied to track the crystallite size and content of tribasic lead sulfates (3BS), and specific surface area of cured paste, using the AZURAD® software. The effect of two quantitative factors (water/LO ratio and acid/LO ratio) and one qualitative factor (curing program) were studied. SEM, XRD and BET were used to characterize the cured pastes. The acid/LO ratio plays an important role in determining the 3BS phase content reaching 78% for crystalline phase. At high temperatures, the acid/LO ratio shows, more influence on the 3BS crystallites size attaining a maximum value of 58 nm. The temperature in the curing step mitigates the effect of both ratios on the crystallites size of 3BS and SSA of cured paste. Results reveals two zones of nanostructured paste material evolution delimited at 10% of acid/LO ratio.

The application of rice husk-based porous carbon in positive electrodes of lead acid batteries

Abstract The positive electrodes of lead-acid batteries are typical thick electrodes where the mass transfer is limited. Therefore, the improvement of the mass transfer inside positive electrode can effectively enhance battery performance. In this article, the rice husk-based porous carbon (RHPC), is applied as an additive in positive electrodes of lead acid batteries. The addition of RHPC can increase the content of 3BS(3PbO·PbSO4·H2O) with decreased crystallinity and particle size in cured electrode. Next, it improves the formation efficiency. The electric conductivity and electron transfer rate of positive electrode are also enhanced. Under 100% DoD discharge condition, the discharge capacity of RHPC electrode increased by 16% and 23% at 0.05C and 1C, compared to that of blank electrode, respectively. Besides, the RHPC experimental cell displays higher discharge specific capacity compared to the blank experimental cell in a long-term deeply charge/discharge process. The developed pore structure of RHPC is beneficial to the curing process, while the developed pore structure and gas production of RHPC make major contributions to the formation and the deeply charge/discharge process. With RHPC additive in PAM, the improvement of the mass transfer can effectively reduces the risk of the failure mode for the mass transfer limit in such a typical thick electrode. Moreover, the particle growth rate of PAM will be inhibited during long-term deeply charge/discharge, thus the addition of RHPC will be very beneficial to increase the cyclic life of the positive electrode.

Electrochemical properties of positive electrode in lead-acid battery modified by ammonium-based ionic liquids

The influence of selected types of ammonium ionic liquid (AIL) additives on corrosion and functional parameters of lead-acid battery positive electrode was examined. AILs with a bisulfate anion used in the experiments were classified as protic, aprotic, monomeric, and polymeric, based on the structure of their cation. Working electrodes consisted of a lead-calcium-tin alloy utilized in the industry for manufacturing current collectors of positive electrodes in lead-acid batteries (LABs). This alloy was used in the first part of the study for the evaluation of corrosion intensity and stability of electrolyte with AIL additives. In the second part, the grid made of the examined alloy was covered with positive active mass, the composition of which was modified by selected AIL. The selection of an appropriate substance was made based on parameters such as corrosion potential, corrosion current, polarization resistance, and hydrogen and oxygen evolution potentials. Techniques such as linear sweep voltammetry, corrosimetry, and electrochemical impedance spectroscopy were used. The conducted measurements revealed that polymeric AIL additive had an exceptionally positive influence on the inhibition of the corrosion process in LAB and electrochemical window of the electrolyte. The influence of this compound on the specific capacity and resistance of the active mass was also discussed.Graphical abstractᅟ

Effect of a mineral additive on the electrical performances of the positive plate of lead acid battery

The objective of this work is to improve the performance of the positive electrode of lead-acid battery. The use of the additive in the positive paste is to increase the capacity and cycle life of the positive active material. Mineral porous additives, dispersed uniformly in the PAM, may act as acid reservoirs and favor the ionic diffusion. The results show that the addition of mineral additive in the paste before oxidation influences the composition and the crystal size of the PAM after oxidation. We observe a remarkable improvement of the discharge capacity of the PAM for an amount of additive ranging between 1 and 5%. Nano-sized particles of PbO2 with amorphous character are obtained. XRD, TG and DSC, SEM, and galvanostatic discharge were used as techniques of investigation.

Investigation of organic expanders effects on the electrochemical behaviors of new synthesized nanostructured lead dioxide and commercial positive plates of lead-acid batteries

Positive electrode with uniform lead dioxide nanostructures was directly synthesized by pulsed current electrochemical method on the lead substrate in 4.8 M sulfuric acid solution. The effect of synthesis parameters were studied by the “one at a time” method on the morphology and particle size of lead dioxide. The composition, morphology and structure were investigated using energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM) and X-ray diffraction techniques (XRD). The effect of conventional organic expanders including humic acid, 1,2-acid (α-hydroxy β-naphtoic acid) and Vanillex was studied on the electrochemical behaviors of the prepared positive electrodes by cyclic voltammetry and on the discharge capacity and cyclelife of commercial positive plates. The used organic expanders improve the performance of negative plates but, they have not positive effects on the performance of positive electrodes of lead-acid batteries.

Cellular/Dendritic Transition and Microstructure Evolution during Transient Directional Solidification of Pb-Sb Alloys

Recent studies of lead-antimony alloys, used for the production of positive electrodes of lead-acid batteries, have assessed the influences of both the microstructural morphology and of solute redistribution on the surface corrosion resistance in sulfuric acid solution, and have shown that cellular structures and dendritic structures have different responses on the corrosion rate of such alloys. The present article focuses on the search of adequate solidification conditions (alloy composition, cooling rate, and solidification velocity), which determine the occurrence of a microstructural transition from the cellular to the dendritic regime during the transient unidirectional solidification of hypoeutectic Pb-Sb alloys and on the microstructural evolution after such transition. The experimental data refers to the solidification of four hypoeutectic Pb-Sb alloys (2.2, 2.5, 3, and 6.6 wt pct Sb) and of the eutectic composition. The experimental results include transient metal/mold heat-transfer coefficients, liquidus isotherm velocity, cooling rate, and cellular and dendritic spacings. It was found that the cooling rate dependence on cellular and primary dendritic spacings is characterized by an experimental law of the form $$ \lambda _{1} = A{\cdot}\ifmmode\expandafter\dot\else\expandafter\.\fi{T}^{{{\kern 1pt} {-0.55}}}, $$ which seems to be independent of composition where A = 60 represents the alloys undergoing a cellular growth and A = 115 can describe the dendritic growth. The sudden change on such multiplier has occurred for the Pb 2.2 wt pct Sb alloy, i.e., for the cellular/dendritic transition.

Studying the Effect of H2SO4/H2O Ratio on the Properties of Positive Electrode in Lead-acid Battery

The lead-acid battery has become so dependable in its used applications of automobile starting, emergency lighting and telecommunications, which left an impression that no further investigation is necessary or desirable. While there has been slow continuous improvements in lead-acid battery performance and mainly limited to design and material engineering. This work is mainly devoted to the properties of the active mass of the positive electrode and the acid/water ratio during the manufacturing process. A field study is carried out at the State Battery Manufacturing Company located in Baghdad, to prepare batches of lead mono-oxide with predefined quantities of liquid additives (i.e. sulfuric acid and water). Quality control and laboratory routine analysis using X-ray diffraction, porosimeter and BET techniques, as well as density, penetration tests of residual lead content ware conducted during the batch process. After the assembling of the positive plates produced during this research into the final product, final testing including electrical capacity and dry charging were performed. It was concluded from the results obtained, that the effective H2SO4/H2O ratio and hence H2SO4/PbO ration and paste density with α/β-PbO2, are the limiting factors of the electrical capacity and durability of the batteries concerned.

Development of positive electrodes with an SnO 2 coating by applying a sputtering technique for lead-acid batteries

In order to prevent positive grid corrosion and to obtain a long life for positive electrodes of lead-acid batteries, a conductive and corrosion resistant SnO 2 (tin dioxide) layer was formed on a Ti (titanium) substrate by a conventional dip-coating method. However, it is impossible to apply this method to a Pb (lead) substrate, because the dip-coating method needs a calcination process, at a temperature higher (conventionally from 450 to 600°C) than the melting point of Pb ( T m: 327°C). For this reason, an SnO 2 layer to protect the substrate against passivation and/or corrosion was formed on Ti and/or Pb electrodes by applying sputtering, a method which is often used in the production of semiconductors. This improved electrode, with an SnO 2 layer, was not corroded at all, even though the thickness of the SnO 2 layer was only about 15 μm. The biggest problem of the SnO 2 layer is that it dissolves in sulfuric acid when the positive electrode is polarized below 0.5 V (versus Pb/PbSO 4). This suggests that this electrode should not be subjected to deep discharge.

Conducting Polymers as the Additives to the Positive Electrode of Lead-Acid Battery

Conducting Polymers as the Additives to the Positive Electrode of Lead-Acid Battery

Effect on cathodic reduction of β-PbO 2 in sulfuric acid solution of surface concentration of Pb 2+ ions formed on β-PbO 2

The discharge reaction of positive electrode of lead-acid battery was investigated with the rotating ring-disc electrode. The large supersaturation of Pb 2+ ion on the electrode surface was obtained during discharge of initial period and the PbSO 4 nuclei was formed. The precipitation of PbSO 4 proceeded smoothly in the presence of PbSO 4 nuclei. In the steady state, the colloidal PbSO 4 film on the electrode surface of which stability depended on the concentrations of sulfuric acids was formed from the dissolving Pb 2+ ions. Especially its stability in 1.0 M H 2SO 4 was so low that the concentration of Pb 2+ ions during discharge was the largest of those in any other sulfuric acids, so that the effect of the film on the overpotential during galvanostatic discharge is the smallest, as discussed in a following paper[1]. The particle sizes of PbSO 4 precipitated during discharge were related to the concentration of Pb 2+ ions on the electrode. These sizes increased with increasing concentration of Pb 2+ ions. If the discharge capacity is limited by the passivation with PbSO 4 crystal, the use of 1.0 M H 2SO 4 as the electrolyte of lead-acid battery may be favoured.