The recycling of lead-acid batteries (LABs) is currently an energy intensive, inefficient and polluting procedure. An alternative hydrometallurgical recycling process is investigated in this study. PbO, PbO2, and PbSO4 were individually reacted with a mixture of aqueous citric acid and sodium hydroxide solution, with hydrogen peroxide being used as a reducing agent for PbO2. Pure lead citrate of either Pb(C6H6O7)·H2O or Pb3(C6H5O7)2·3H2O was the product crystallized in each leaching experiment depending on the initial conditions. Combined spent electroactive paste materials from industry were leached and processed. 2.5 M H2O2, 3.2 M C6H8O7·H2O and 3.5 M NaOH were used for optimal leaching and were successful in synthesising Pb3(C6H5O7)2·3H2O after less than one hour. These amounts could be reduced by individual leaching of plate materials. The combustion-calcination of Pb3(C6H5O7)2·3H2O was successful in generating PbO containing both forms of the polymorph α and β crystal phases together with metallic Pb. A novel method to generate PbO from lead citrate was found through a self-sustaining combustion route where leached waste materials were preheated to 270 °C for ~15 minutes and were found to self-sustain a smouldering reaction to produce PbO with a predominately β phase containing metallic Pb. Electrochemical analysis of PbO from Pb3(C6H5O7)2·3H2O demonstrated the viability in the by-product to be used in an electroactive paste and therefore reused in new LABs. Pure α-PbO was generated from both forms of lead citrate, Pb(C6H6O7)·H2O and Pb3(C6H5O7)2·3H2O using NaOH. Pure β-PbO was also generated from Pb(C6H6O7)·H2O and Pb3(C6H5O7)2·3H2O using NaOH through dissolution/re-precipitation reactions. PbCO3 was successfully generated from Pb(C6H6O7)·H2O and Pb3(C6H5O7)2·3H2O using NaOH, NaHCO3 and an acid in a series of disassociation and re-precipitation reactions. PbCO3 could be used to thermally generate α and β-PbO as well as Pb3O4 by calcination at 350, 600 and 450 °C respectively. Glycerol was entrained in both PbCO3 and α-PbO as an in-situ reducing agent to generate PbO containing metallic Pb. Acid reactivity and absorption characteristics of PbO derived from Pb3(C6H5O7)2·3H2O heated in CO2 were equal to and greater than those used in industry for both automotive and industrial batteries.

This thesis investigates the performance of pulse charging, which is believed to be superior to constant current charging in some respects, such as charging efficiency and charging speed. The investigation is focused upon the extensively used secondary batteries, lead-acid batteries. The consecutive orthogonal arrays method is applied to search for the optimum operating variables of pulse charging, including pulse amplitude, duty ratio and frequency of the charging current. Unfortunately, the experimental results of consecutive orthogonal arrays reveal that charging efficiency is not obviously affected by pulse amplitude, duty ratio or frequency. Instead, charging rate is dominantly influenced by average charging current. These results indicate that pulse charging scheme is not superior to constant current charging. To compare these two charging schemes further, a series of experiments are carried out to discuss the effects of each operating variables. Unfortunately, no evidence from the experimental results can prove the superiority of pulse charging to constant current charging as formerly documented.

The work in this thesis is focused on the development and validation of an automotive battery monitoring system that estimates the health of a lead-acid battery during engine cranking and provides a low state of health (SOH) warning of potential battery failure. A reliable SOH estimation should assist users in preventing a sudden battery failure and planning for battery replacement in a timely manner. Most commercial battery health estimation systems use the impedance of a battery to estimate the SOH with battery voltage and current; however, using a current sensor increases the installation cost of a system due to parts and labor. The battery SOH estimation method with the battery terminal voltage during engine cranking was previously proposed. The proposed SOH estimation system intends to improve existing methods. The proposed method requires battery voltages and temperature for a reliable SOH estimation. Without the need for a costly current sensor, the proposed SOH monitoring system is cost-effective and useful for automotive applications. Measurement results presented in this thesis show that the proposed SOH monitoring system is more effective in evaluating the health of a lead-acid battery than existing methods. A low power microcontroller equipped prototype implements the proposed SOH algorithm on a high performance ARM Cortex-M4F based MCU, TM4C123GH6PM. The power dissipation of the final prototype is approximately 144 mW during an active state and 36 mW during a sleep state. With the reliability of the proposed method and low power dissipation of the prototype, the proposed system is suitable for an on-board battery monitoring as there is no on-board warning that estimates the health of a battery in modern cars. / Master of Science

This thesis describes the development of a system to continuously monitor the battery in a car and warn the user of an upcoming battery failure. An automotive battery endures enormous strain when it starts the engine, and when it supplies loads without the engine running. Note that the current during a cranking event often exceeds 500 Amperes. Despite the strains, a car battery still typically lasts 4-6 years before requiring replacement. There is often no warning of when a battery should be replaced and there is never a good time for a battery failure. All currently available lead-acid battery monitoring systems use voltage and current sensing to monitor battery impedance and estimate battery health. However, such a system is costly due to the current sensor and typically requires an expert to operate the system. This thesis describes a prototype system to monitor battery state of health and provide advance warning of an upcoming battery failure using only voltage sensing. The prototype measures the voltage during a cranking event and determines if the battery is healthy or not. The voltage of an unhealthy battery will drop lower than a healthy one, and it will not recover as quickly. The major contributions of the proposed research to the field are an algorithm to predict automotive battery state-of-health that is temperature-dependent and a prototype implementation of the algorithm on an ARM processor development board. / Master of Science

Although competitive today, traditional PbA (<1500 cycles) and advanced lead-acid batteries (ALAB) (>4000 cycles) will not be able to compete with lithium and flow batteries by 2020. To compete with novel zinc, lithium and flow batteries, the PbA chemistry needs to achieve significant performance improvements, primarily through sustainable increases to specific energy (Wh/kg), while not negatively impacting cycle life. Inverse charging has been examined for its potential in improving PbA cycle life as a battery maintenance procedure, and as a potential technique for improving electrode specific capacity (mAh/kg) during battery manufacturing and formation. A thorough levelized cost of energy (LCOE) shows that for traditional PbA batteries with cycle lives <2000, inverse charging as a maintenance strategy (to increase cycle life) improves battery economics. Inverse charging to increase cycle life for ALAB systems (>4000 cycle life) was proven to worsen battery economics, as additional costs of capital and maintenance fail to outweigh savings achieved through reductions in replacement cost. On the other hand, inverse charging employed as a manufacturing practice to increase specific energy dramatically reduces the cost of the PbA and ALAB systems, ensuring future cost competitiveness. Inverse charging as a maintenance strategy should be restricted to devices with <2000 cycles and to projects with long project lives (20 years) that require frequent replacement. Inverse charging as a manufacturing strategy (to increase specific energy) is highly preferable in all instances. When successful, inverse charging increases the specific capacity and active material utilization of studied battery electrodes significantly. Successful inverse charging of battery electrodes and pure lead rods show improvements in discharge capacities over a range of discharge rates with negligible impact to coulombic and energy efficiency values. The extent of success, however, depends on several important variables. Thorough examination of inverse charging on Pb rods and porous battery electrodes illustrates the importance of the degree of prior electrode sulfation and obstruction of transport of H₂SO₄. Other important factors include the composition of electrode grid alloys, the peak oxidation voltage applied to the negative electrode during inverse charging, initial particle sizes, and electrolyte additives. Significant challenges to inverse charging exist. For heavily sulfated batteries and lead metals, impeded electrolyte transport results in excessive internal pore pH increases, creating semipermeable membranes through an electrode hydration mechanism, resulting in dramatic inverse charging failure. Additionally, impedance, voltage, x-ray and BET data hint that post-inverse charging, agglomeration of finely divided Pb and PbSO₄ particles occurs, coupled with negative electrode conductive pathway destruction. As such, the influence of expander materials and nucleation additives should be investigated to better prevent sulfation failure, and to better control the nucleation and growth of lead and lead sulfate structures during inverse charging. Cycle life studies on flooded lead antimony batteries subjected to periodic inverse charging illustrate that inverse charging is highly successful on all batteries independent of states-of-health. Batteries with poor states-of-health (discharge capacities <15% of initial values) experienced almost perfect discharge capacity restoration post-inverse charging. Traditional methods of extending cycle life (i.e. prolonged overcharging techniques) were demonstrated to be inadequate at appreciably regenerating battery capacities, providing only marginal increases. The benefits of inverse charging, however, are met with significant challenges to battery redesign. Temporary antimony poisoning effects lead to declines in round-trip-efficiency for batteries with antimony-based positive plates. Tin dissolution results in diminished grid to active material conductivity and reduced capacity for batteries with tin-based positives. For the negative electrode, Brunauer–Emmett–Teller (BET) surface area and x-ray measurements indicate that although large PbSO₄ crystals are oxidized during inverse charging, creating extensive micropore networks during conversion from Pb to PbO₂, surface area and capacity gains are lost during reconversion back to sponge lead due to uncontrolled nucleation and particle fusion. Additionally, active material shedding of the positive and negative electrodes is observed to spike during and after inverse charging. Negative electrode active material suffers excessive degradation and loss of cohesion, particularly for electrodes with small initial particle feature sizes, resulting in a loss of structure upon completion of the technique. Positive electrode composition changes to weakly interconnected b-PbO₂, dramatically increasing electrode capacity while simultaneously accelerating electrode failure through shedding. Loss of particle cohesion in both electrodes promotes excessive shedding and sludging, creating intra-cellular short-circuits. In addition, inverse charging aggravates grid growth, promoting inter-cellular short-circuiting by creating pathways for cell-to-cell electrolyte contact upon seal destruction in current monoblock designs.

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references.

Lead acid batteries are widely used in domestic, industrial and automotive applications. Even after lot of advancements in battery technologies, lead acid cells are still in use because of their high capacity and low cost. To use any battery effectively, first we should be able to identify the available capacity or State of Charge (SoC). There are many techniques available to measure SoC of a lead acid battery. One such unique method is to measure the capacity using eddy current sensors. This method is unique because it is non-obtrusive and online. Eddy current sensors (ECS) are wire wound inductors which work on the principle of electromagnetic induction. Eddy currents are the currents generated on a conductive material when it is kept in a varying magnetic. Eddy current sensors generate varying magnetic eldest and will be able to identify the properties of conductive materials like thickness, conductivity, material composition etc. Also they can be used as proximity sensors. Lead acid batteries use lead metal as cathode. Upon usage(discharge) the lead metal converts to lead sulfate and revert back to lead after charging. These changes in lead electrode can be monitored using eddy current sensors. The impedance of an eddy current sensor will change when it is kept close to the lead electrode when the battery is charging or discharging. These impedance parameters can be monitored to determine the battery SoC. When lead is deposited on cathode, there will be more eddy current loss in the target and the total resistance of coil increases. On the other hand, when lead is deposited on the electrode because of increase in the magnitude of eddy currents which oppose the source magnetic, the total inductance of coil decreases. We can observe exactly opposite behaviour of coil resistance and inductance when the lead electrode is converted to less conductive lead sulfate. There is a lot of research on using ECS to measure SoC of lead acid batteries and there are still many challenges to be addressed. First we have explained about different circuit designs we have used to monitor the battery capacity using eddy current sensors. After that, we have explained about our complete experimental setup and the procedure to measure the sensor parameters using the setup. Then, we have discussed about different issues involved in the eddy current sensing based state of charge measurement. Eddy current sensors are affected by temperature variations. We have studied the coil resistance behaviour with temperature at different frequencies using simulations and experiments. We have obtained the conditions for linear variation of coil resistance with temperature. The measured temperature compensation scheme is applied and the results are discussed. We have also modified the measurement system design in order to minimize the lift o errors. We have used a metallic clamp structure to minimize the lift o errors. We have used finite element analysis based simulations to study different design parameters and their effect on the sensitivity of eddy current sensor. We have created 2D eddy current models and the sensitivity of coil resistance is computed by changing the coil dimensions and the core permeability. We have also performed error analysis and computed the error due to the tilt angle shift between coil and electrode. We have also computed the error due to the internal heating of battery. We have also studied the effect of acid strati cation on state of charge for both sealed and hooded batteries. We have proposed a multi coil method to minimize the errors in SoC measurement due to acid strati cation for Flooded type batteries. We have used finite element analysis based simulations to compute the error due to acid strati cation by increasing the number of coils. Finally we have derived the equation for electrode Q factor using the transformer model of eddy current sensor. The derived Q factor equation is then used to study the aging of lead acid batteries both by using experiments and simulations. Finally we have explained a detail procedure to measure the state of charge(SoC) and state of health(SoH) of a hooded lead acid battery using eddy current sensing method.

No description available.

This thesis studies the operating characteristics of lead acid batteries with the intermittent discharging current. Rest time is added periodically on purpose during the battery discharging to observe its impact on the releasable capacity. From the experimental results that take the frequency and the duty-ratio as two variables, batteries with the intermittent discharging at high frequencies or low duty ratios can release more capacity. The results also indicate that the depth of discharge (DOD) affects the intermittent discharging. More capacity is released while approaching the end of the discharging, whereas no clear difference is found in the beginning. Last but not least, the average current is proved experimentally to play a significant role in current discharging. With the same average current, the maximum capacity obtained from the intermittent current discharging is close to that from the constant current discharging.

Ecologist Tom Dale and Vernon Gill Carter Published a book ¡mTopsoil and Civilization¡n in 1955, There is a paragraph in the prolog¡G ¡uCivilized human always can temporarily control the environment mostly. Their main problem caused of the misconceiving that the temporary control can be forever. They misconceive that they are the ¡§dominator of the world¡¨, but don¡¦t realize the rule of the nature at all. Human no matter civilized or not, nevertheless, is the son not the master of nature. If they want to sustain and maintain the ecological environment, their behavior must follow the rule of nature. If they try to evade these rules, the consequence usually ruins the surrounding environment what nurture them. When the environment gets worst rapidly, their civilization declines too.¡v It seems to be a fate, like Morrie said in ¡mTuesday with Morrie¡n¡G¡uEvery one knows he will die, but nobody takes it as real.¡vHuman does not only treat his own life like this way, but also the environment what they survive and live in! From 1992, ¡¦Rome Club¡¦ published the book ¡mThe limit of growth¡n, the consciousness of environmental protection started to head up. Some issues like Ecology of commerce, Sustainable development, Land ethics, Deep ecology and Environmental economic came out one after one. Purely economic and efficient considering of design and production can¡¦t satisfy these kinds of demand. For this sake, International Standard Organization issued out the ISO-14000 series and accepted worldwide gradually. ISO-14040¡GLife Cycle Assessment¡Aevaluating the impact to the environment from material input, manufacturing, transportation, using, recycle, disposal, by other words--- ¡¥from the cradle to grave¡¦. LCA try to use quantitative concept to interpret the environmental impact or damage from human made product. It may provide environmental protection user a systematic thinking to distinguish which product is environmental amity product, which is not; also could be a stand for environment strategy. Applied on the production, it can be a good tool for ¡¥Green Design¡¦ thinking, to reduce the impact to the environment from every stage in production. This thesis is going to study the 6V4Ah Lead acid battery that used widely in the market. Quoting LCA¡¦s indications and SimaPro 4.0 software developed by Pre Consultants B.V. as the database and tools to evaluate the impact and damage to our environment. About the basic data bank, we adopt the local databank built by ITRI (Industrial Technology Research Institute) for years and the data included in SimaPro software. Those are Pre4, PreNL, BUWAL250 and IDEMAT96. Following the analysis procedures as Classification, Normalization, Evaluation by both impact orientation method --- Eco-indicator 95 method and damage orientation method --- Eco-indicator 99 method to evaluate this product¡¦s LCA study. Further more, look forward to provide a potential evaluation way to evaluate and compare to other various batteries.