Positive Lead Acid Battery Plates Research Articles

PEDOT-coated rice husk-based activated carbon: Boosting lead-acid battery performance

Despite the surge in novel energy storage systems, lead-acid batteries remain entrenched in the market, chiefly attributed to their well-established technology, affordability, and dependable safety profile. Yet, they are not without shortcomings, notably their limited energy density and abbreviated cycle life. The profound impact of positive electrode materials on lead-acid batteries is undeniable, as these materials directly dictate the batteries' charging and discharging efficiency, energy density, cycle longevity, and overall stability. Here we report on an innovative positive active material additive, wherein the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is coated onto rice husk-based activated carbon (RHAC) surfaces via in-situ polymerization in solution to form a composite material (PEDOT@RHAC). Astonishingly, lead-acid batteries fortified with PEDOT@RHAC within their positive plates showcased remarkable electrochemical prowess. Incorporating PEDOT@RHAC into the positive plates of lead-acid batteries has demonstrated exceptional electrochemical performance. The enhanced deep cycling capability of these batteries is evident, with a substantial increase in cycle life by 2.08 times and an augmentation in discharge capacity by 1.3 times compared to the control batteries. This positive electrode additive plays a pivotal role in augmenting the overall performance and extending the lifespan of lead-acid batteries, potentially paving the way for their broader commercial application.

Electrochemical Performance Analysis of Lead Dioxide Prepared from Intermediate Oxides

Intermediate oxides are synthesized by heating fresh lead dioxide obtained from commercial positive plates of lead-acid batteries. These oxides are soaked in sulfuric acid with 1.28 s g under stirring for 1 h. The obtained powders are analyzed using X-ray diffraction and chemical analysis. The samples are discharged with a cathodic current of 1 mA in sulfuric acid with 1.28 s g, and the capacity is determined. It is found that lead dioxide obtained from PbO1.55 is more active than the fresh sample. It shows an increase in capacity of 17%. This is due to the increase in the quantity of structural water as given by the chemical and thermal analyses.

Controlled Nano-Crystallization for Optimizing of Lead Acid Positive Active Material Using Graphene Nano-Composites

Controlled Nano-Crystallization for Optimizing of Lead Acid Positive Active Material Using Graphene Nano-Composites

Investigating the use of porous, hollow glass microspheres in positive lead acid battery plates

Porous, hollow, glass microspheres (PHGMs) can be used to increase porosity in lead acid battery electrodes to improve the battery's power and energy performance at higher discharge rates. As reported in this paper, the PHGM additives did improve electrolyte storage and porosity in the electrodes. However, the nonconductive PHGMs do reduce the critical volume fraction (CVF) of the electrodes as predicted from conductivity models. The increase in electrode performance due to increased porosity may therefore be partially offset by the drop in capacity due to a lower critical volume fraction. Empirical equations are developed that relate the CFV and porosity of an electrode to the amount, size, and porosity of the additives in that electrode. The porosity estimates made from the empirical equations compare favorably with the experimental data from plates fabricated with these additives. The performance of electrodes with additives is estimated from computer models using the electrode's CVF and porosity as provided by the equations. Tests were performed on plates having volume loadings of PHGMs from 11% to 44% of total solids in positive electrodes to determine their effect on active material utilizations. The results from these discharge tests are reported and compared with theoretical models.

12 V / Kilo-Farad Range Lead-Carbon Hybrid Ultracapacitors and Their Envisaged Applications

12 V substrate-integrated lead-carbon hybrid ultracapacitors (HUCs) where in the conventional positive plates of lead-acid batteries are replaced with substrate-integrated PbO2 positive plates and the negative plates are replaced with carbon-coated graphitic electrodes, providing totally non-faradaic and corrosion-free electrodes, are developed and performance tested. Constant-current discharge data at varying load-currents, constant-power discharge data at varying power values, and the capacitance data at different temperature for a 12 V / kF range substrate-integrated lead-carbon HUC are described along with its resistance, leakage current, self-discharge and cycle-life characteristics.

Experimental and theoretical investigation of nonconductive additives on the performance of positive lead acid battery plates

Additives can be added to lead acid battery electrodes to increase porosity and improve battery power and energy performance. This paper investigates the influence on electrode performance of different sizes and volume percentages of nonconductive additives to provide a clearer understanding of how they affect battery performance. The nonconductive additives used in the electrodes were hollow glass microspheres (HGMs). The solid volume percentages of various sizes of HGMs were varied from 5 to 60%. The discharge capacity for different volume percentages of the HGMs was measured in plates that were hand pasted to similar thicknesses. The utilization of active materials, which is defined as the ratio of the practical discharge ampere-hours over the stoichiometric capacity of the active materials, was plotted with respect to different solid volume percentages of additives. Experimental results were compared with the theoretical values of conductivity models. The change of utilizations with different solid volume percentages of additives compared favorably with the model predictions.

Porosity Measurements of Positive of Lead-Acid Battery Plates by Mercury PSorosimetry

A mercury porosimeter has been used to measure the intrusion volume of the three types mercury positive lead acid-battery plates. The intrusion volumes were used to calculate the pore diameter, pore volume, pore area, and pore size distribution. The variation of the pore area in positive lead acid-battery plates as well as of the pore volume has the following sequence. Paste positive > Uncured positive > Cured positive

Porosity Measurements of Positive of Lead-Acid Battery Plates by Mercury PSorosimetry

A mercury porosimeter has been used to measure the intrusion volume of the three types mercury positive lead acid-battery plates. The intrusion volumes were used to calculate the pore diameter, pore volume, pore area, and pore size distribution. The variation of the pore area in positive lead acid-battery plates as well as of the pore volume has the following sequence. Paste positive > Uncured positive > Cured positive

Sodium Sulfate Effects on the Electrochemical Behaviors of Nanostructured Lead Dioxide and Commercial Positive Plates of Lead-Acid Batteries

Sodium Sulfate Effects on the Electrochemical Behaviors of Nanostructured Lead Dioxide and Commercial Positive Plates of Lead-Acid Batteries

Barium Sulfate Effects on the Electrochemical Behaviors of Nanostructured Lead Dioxide and Commercial Positive Plates of Lead-Acid Batteries

Positive electrode with uniform lead dioxide nanostructures directly synthesized by cyclic voltammetry (CV) method on the lead substrate in 1 M sulfuric acid solution including different concentration of barium sulfate. The effect of potential scan rate, sulfuric acid and barium sulfate concentration were studied on the morphology and particle size of lead dioxide using scanning electron microscopy (SEM) and X-ray diffraction techniques (XRD). The effect of barium sulfate was studied on the CV parameters including anodic peak current (I p a ), cathodic peak current (I p c ), anodic peak potential (E p a ) and cathodic peak potential (E p c ) during synthesis process. Finally, the effect of barium sulfate on the discharge capacity and cycle life of nanostructured positive electrodes and commercial positive plates was investigated. Both CV and battery test results showed that barium sulfate with concentration of 1 × 10−5 M can be used as suitable additive for positive paste of lead-acid batteries.

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.

Discharge mechanisms and electrochemical impedance spectroscopy measurements of single negative and positive lead-acid battery plates

This study interpreted open circuit impedance measurements of single negative and positive lead-acid battery plates, which were at different discharge levels and arranged in a four-electrode cell. This was performed in the framework of a proposed general model of charge/discharge reactions, morphological models of active materials, and based on interpretation of the characteristics of single negative and positive plates as measured by electrochemical impedance spectroscopy (EIS). This study shows that the proposed reaction models, morphological characteristics and EIS attributions are compatible with the obtained EIS data. The analysis indicates that negative and positive plate reaction mechanisms cannot be those proposed by the dissolution–precipitation mechanism alone. Rather, the reactions seem to obey the various mechanisms and morphologic ideas proposed in the present paper. It is shown that variations in the resistivity and dielectric constants of discharged films need to be studied in greater detail than film thicknesses to gain a better understanding of the processes.

Influence of some metal ions on the structure and properties of doped β-PbO 2

The lead dioxide active mass of positive lead-acid battery plates is a gel-crystal system with proton and electron conductivity of the hydrated gel zones. This paper discusses the influence of Sn 2+, Sb 3+, Co 2+, Mg 2+ and Al 3+ ions, added to the formation electrolyte, upon the stoichiometry, structure and phase composition of the PbO 2 positive active material (PAM) of lead-acid batteries. PAM samples doped with the above metal ions are characterized by: X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and chemical analysis. The obtained results show that different metal ions are incorporated in different quantities in the PbO 2 particles. Under the influence of dopants, the stoichiometric coefficient of lead dioxide decreases, i.e. dopants increase the non-stoichiometry of PbO 2. The foreign ions in the formation electrolyte exert strong influence on the microstructure of PAM and change the proportion between crystal and hydrated gel zones in the particles.

Influence of paste composition and curing program used for the production of positive plates with PbSnCa grids on the performance of lead acid batteries

The cycle life performance of lead acid batteries with PbSnCa grids is strongly affected by the structure and properties of PAM and of the interface PAM/grid. The latter interface is formed during curing and formation of the positive plates. The processes that take place on curing of positive lead acid battery plates produced with Concast or Conroll PbSnCa grids and 3PbOPbSO 4·H 2O (3BS) or 4PbOPbSO 4· xH 2O (4BS) pastes are discussed in this paper. The enhanced processes of Sn and Ca segregation in the alloy of the grids during plate curing lead to the formation of a thin layer of a new phase, composed of the intermetallic compound (Pb 1− x Sn x ) 3Ca, in the spaces between the metal grains or sub-grains. This layer makes the interface heterogeneous and exerts a detrimental effect on the cycle life of the battery. In order to suppress its effect on battery performance, the thickness of this layer should be reduced by reducing the content of Ca in the grid alloy. During plate curing, the heterogeneous surface of the grid alloy is oxidized under the action of oxygen and H 2O at elevated temperature and the alkaline solution in the paste pores. A corrosion layer is formed comprising a thin sub-layer (CL1) and a thick partially hydrated lead oxide sub-layer (CL2). The 4BS/CL2 contact surface is larger and more stable than that between the 3BS particles and the CL2 layer. Both 3BS and 4BS particles are bonded to the CL2 layer through their hydrated layers. When curing is conducted at temperatures above 80 °C, 3BS particles are converted into 4BS ones which contain water. It has been established that positive plates produced with 4BS plates cured at 50 °C have the longest cycle life and adequate capacity performance, but a bit low power output. Positive plates prepared with 3BS pastes, which are then converted into 4BS ones during plate curing at 90 °C, have high initial capacity and power performance, but shorter cycle life. Batteries with plates produced with 4BS pastes and then cured at 90 °C for less than 4 h have both satisfactory power output and cycle life. The obtained results indicate that the conditions of positive plate curing exert a strong influence on the performance of batteries with PbSnCa grids.

An electrochemical technique for state of charge (SOC) probing of positive lead–acid battery plates

Electrochemical experiments that intend to characterise the state of charge (SOC) of lead–acid battery positive plates are presented. These experiments are designed for potential battery plate production quality control and in situ monitoring of battery condition. A small size probe, consisting of a counter and a reference electrode encased in a glass body ending to a fine aperture tip and pressed onto the specimen, was used to apply cathodic galvanostatic pulses on positive plate battery samples. Although this probe arrangement is similar to that of a coulometric thickness gauge, the porous nature of the battery plate results eventually in full discharge of the entire specimen. However, during the initial stages of specimen discharge using the contact probe, a potential arrest was observed for fully charged and partially discharged samples and it was attributed to the time needed for the thickness of a PbSO 4 film formed during discharge and the corresponding resistance under the probe’s tip to reach a critical value for the discharge to spread to the rest of the sample. The duration of this potential arrest was found to be related to the positive plate’s SOC indicating the possibility of using the technique in positive plate quality control or in situ monitoring.

Phenomena That Limit the Capacity of the Positive Lead Acid Battery Plates : II. Electrochemical Impedance Spectroscopy and Mechanism of Discharge of the Plate

This paper is the second part of an investigation whose purpose is to establish the mechanism of the processes that proceed during discharge and cycling of the lead dioxide plate of the lead acid battery (LAB). On the basis of this mechanism some electrical parameters that can show the state-of-charge (SOC) and state-of-health (SOH) have to be distinguished. In the first part of this study the shape of the charge potential transient was examined. In this part the electrochemical impedance spectra of a model lead dioxide electrode was investigated in charged and discharged states as well as the changes in impedance spectra during cycling of the electrode with high and low charge currents. It was established that during cycling the values of charge-transfer resistance ion diffusion resistance in the reaction layer, resistance of the grid/PAM interface and ohmic resistance of the electrode change smoothly at first with cycling and after a critical number of cycles have been reached, they start to increase fast. This shows that the electrode is close to the end of its life. The above parameters can be used for the determination of SOH of the positive LAB plate. The discharge processes take place on active centers (ACs) in positive active material (PAM) and interface. A model of the structure of ACs as well as a scheme of the elementary reactions proceeding at discharge in the ACs is proposed. During cycling when the number of ACs in PAM decreases and this one in the interface increases, the capacity of the electrode decreases. On the basis of the changes in the impedance spectra at discharge and charge the changes in equivalent electrical circuit are discussed. © 2002 The Electrochemical Society. All rights reserved.

Phenomena That Limit the Capacity of the Positive Lead Acid Battery Plates : I. The Charge Potential Transient as an Indicator of Positive Plate State of Charge and State of Health

The capacity of the positive plate of the lead-acid battery is determined by the number of the active centers in positive active material (PAM) where the reaction proceeds and by the resistance of the interface corrosion layer (thin PAM layer interconnecting the PAM and the CL). It was established that the number of the active centers is high if the positive plate discharge is performed with low current and if the charge (at the initial period) is performed with high current. During discharge the active centers from the outer layer of the plate are exhausted and the reaction of the reduction approaches the inner part of the plate near the interface and the interface itself. If the pH of the pore solution is low the reduction of the proceeds to At the subsequent charge with sufficiently high current a maximum appears on the potential transient. When the flux to the interface is impeded, the pH of the solution in the pores in the interface is high and the reduction of the proceeds to As the has high electrical resistance, during the subsequent charge with high current a peak appears at the beginning of the potential transient. Its height depends on the resistance of the interface. On the basis of the appearance of a maximum or a peak the state of change and the state of health of the positive plate can be determined. © 2002 The Electrochemical Society. All rights reserved.

Semi-suspension technology for preparation of tetrabasic lead sulfate pastes for lead-acid batteries

A new technology for production of 4BS pastes for the positive (lead dioxide) plates of lead-acid batteries has been developed based on an Eirich Evactherm ® mixer. The basic principle of this new technology is that 4BS crystals with dimensions between 20 and 25 μm are formed first from a semi-suspension at a temperature higher than 90°C and then the excess water is removed from the semi-suspension under vacuum until the desired paste density is obtained. During the vacuum treatment the temperature of the paste decreases and small 4BS and PbO crystals are formed. During the paste formation procedure, the large 4BS crystals build up the PbO 2 skeleton of the PAM, whereas the small crystals form the energetic PbO 2 structure, which participates in the charge–discharge processes on cycling of the battery. It has been found, through XRD and thermogravimetric analysis, that the 4BS particles comprise crystal and amorphous zones. The crystal zones contain water molecules, part of which can be easily removed from the particles under vacuum treatment and curing as a result of which the crystallinity of the 4BS particles decreases. Another part of the bound water remains in the 4BS particles after curing of the pastes and can leave them only after heating to 250°C. The ability of water to leave the particles depends on the density of the semi-suspension used for preparation of the paste. Experimental tests have shown that the highest battery performance is obtained when the paste is prepared under the following conditions: degree of lead oxidation in the leady oxide (LO) 85% PbO/LO, H 2SO 4/LO ratio 5–6%, liquid content (H 2SO 4+H 2O) in the semi-suspension 240–260 ml/kg LO, temperature of the semi-suspension equal to or higher than 90°C, duration of paste mixing about 15 min. The new semi-suspension technology of 4BS paste preparation facilitates the formation of stable PAM structure that ensures high capacity and long cycle life of the positive plates of lead-acid batteries.

00/02615 Influence of fast charge on the life cycle of positive lead-acid battery plates

00/02615 Influence of fast charge on the life cycle of positive lead-acid battery plates

Influence of fast charge on the life cycle of positive lead–acid battery plates

A criterion has been found for determination of the factor limiting the discharge of the lead dioxide plate. When on discharge with moderate currents, an arrest or a shoulder appears between 1.0 and 0.7 V (vs. Hg/HgSO 4 electrode) in the potential transient, then the charging potential transient features a peak at the beginning of the curve. The capacity is limited by the interface. The life cycle of the battery is short. This phenomenon is known as PCL effect. When a broad maximum occurs in the potential transient on charge, this indicates that the electrode capacity is limited by zones of high resistance in positive active mass (PAM) near the interface. The capacity is determined by the lead dioxide active mass. It has been established that the life of the positive plate is proportional to the current density during the initial charge stage. A sol–gel–crystal mechanism of the charge processes is proposed to explain this effect of fast charge on electrode life. The high rate of the electrochemical reaction leads to high oversaturations of the Pb(OH) 4 sol and to fast formation of gel–crystal PbO(OH) 2/PbO 2 particles, which not only form new agglomerates tightly connected to the PAM skeleton, but also fill in and improve the contacts between the agglomerates. The latter process has the effect of “welding” of the PAM skeleton. Moreover, the higher concentration of the Pb(OH) 4 sol affects the macro- and microstructure of the PAM, which in turn has an influence on the electrochemical reaction. Impedance measurements have evidenced different values of the electron transfer resistance in electrodes charged at high and low currents.