Waste Lead-acid Batteries Research Articles

Effect of microwaves on the repair of lead-acid batteries

Abstract Lead-acid batteries are widely used in the automotive industry, and a large amount of waste lead-acid batteries cause enormous pressure on resources and the environment. Repairing aging lead-acid batteries is an effective way to solve this problem. Due to the fact that microwaves can affect most chemical reactions and promote their progress, this paper will study the repair effect of microwaves on lead-acid batteries by combining theory and experiment methods. By analyzing the reaction principle of lead-acid batteries, a multi-physics model is established to study the influence of microwaves on the lead-acid batteries, and an experimental system is built to test the changes in capacity and final charge voltage of lead-acid batteries under the radiation of microwaves. The results demonstrate that microwave treatment significantly enhances the capacity of aging lead-acid batteries, particularly when the initial capacity is slightly above 50% of the rated capacity. Moreover, heating the battery with hot air alone hardly affects its capacity. This study reveals that microwaves have reparative effects on lead-acid batteries, providing a new method for repairing aging batteries.

Recovering metallic lead from spent lead paste by slurry electrolysis

Spent lead paste, the most challenging component of discarded lead-acid batteries, contains approximately 70 % Pb. Improper handling of lead-acid battery waste poses severe risks to both the environment and human health. Here, we present a novel and short process for directly recycling metallic Pb from spent lead paste by chlorine slurry electrolysis and investigate the parameters that affect Pb recovery rate and cathodic current efficiency. Our experiments showed that under optimal conditions (250 g/L NaCl, 0.8 mol/L HCl, 10 g/L Pb2+, 30 A/m2, 40 g/L pulp concentration, 65 °C, and 12 h), the Pb recovery rate and cathodic current efficiency were, respectively, 90.54 and 85.25 %. During slurry electrolysis. Cl- combined with Pb in spent lead paste in the anode chamber, converting lead oxides and insoluble PbSO4 into soluble lead chloride complexes ([PbCl3]-, [PbCl4]2-). Driven by the electric field and concentration gradient, the lead chloride complex ions then migrated to the cathode region, where they were reduced to metallic Pb with a purity higher than 99 %. The application of this cost-effective and efficient novel method can contribute to the sustainable reuse of waste lead-acid batteries and other Pb-bearing scrap.

CO2 electrolysis to formic acid for carbon neutralization

To avoid carbonate precipitation for CO2 electrolysis, developing CO2 conversion in an acid electrolyte is viewed as an ultimately challenging technology. In Nature, Xia et al. recently explored a proton-exchange membrane system for reducing CO2 to formic acid with a Pb–PbSO4 composite catalyst derived from waste lead-acid batteries based on the lattice carbon activation mechanism. Up to 93% Faradaic efficiency was realized when formic acid was produced by this technology.

A Review on Recycling of Waste Lead-Acid Batteries

Lead-acid batteries (LABs) have become an integral part of modern society due to their advantages of low cost, simple production, excellent stability, and high safety performance, which have found widespread application in various fields, including the automotive industry, power storage systems, uninterruptible power supply, electric bicycles, and backup power supplies. Hence, the use of LABs has greatly benefited human society and contributed to advancements in science and technology. However, the extensive use of LABs unavoidably leads to the generation of a significant amount of LABs waste. On one hand, if these waste LABs are not handled properly, any leakage can cause devastating damage to the natural environment and human health. On the other hand, waste LABs represent an important secondary resource for lead, with approximately 64.57% of global lead resources derived from recycled lead, making them a major source of lead worldwide. Moreover, approximately 85% of global lead resources are currently utilized for manufacturing LABs, and the recycling of waste LABs brings favourable prospects for the sustainable development of the energy storage industry. Therefore, the recycling of waste LABs is necessary and inevitable. In this paper, we have comprehensively reviewed the methods of recycling waste LABs. Particularly, we focused on the valuable component of waste lead paste and critically evaluated the pyrometallurgical and hydrometallurgical techniques associated with it. By categorizing and summarizing the characteristics of different methods, we have conducted a detailed comparison of these technologies, aiming to provide a comprehensive assessment of the advantages, disadvantages, status, and trends in LABs recycling technology. Additionally, the paper explores the necessity and impacts of recycling waste LABs from the perspectives of resource, energy, economy, environment, and society. It discusses the challenges faced by waste LABs recycling and presents the development prospects from both technical and non-technical point of views.

An environment-friendly strategy for recovery of α-PbO from spent lead paste: Based on the thermochemical reduction of PbO2 with ammonium sulfate

During the process of recycling lead from waste lead-acid batteries, how to minimize the wastage of chemical reagents and prevent secondary pollution is a significant research subject. In this study, a method for preparing α-PbO based on low-temperature thermochemical reduction of PbO2 was proposed. Using (NH4)2SO4 as the roasting agent, the purity of PbSO4 in spent lead paste was improved by reducing PbO2 at low temperatures. The thermochemical mechanism revealed that the thermochemical process consists of three different stages of (NH4)2SO4 decomposition and PbO2 reduction. The purity of PbSO4 in spent lead paste could be increased to 98.43 % by controlling the thermal reaction conditions (M (SO42−: TPb) molar ratio of 1:1, roasting temperature, and time of 340 °C and 1.5 h, respectively). Then, the desulfurization of PbSO4 with (NH4)2CO3 obtained PbCO3, and α-PbO with a purity of 96.87 %-98.57 % could be obtained by pyrolysis of PbCO3. Finally, 95.63 % of NH4+, 97.34 % of SO42−, and 77.71 % of CO32− could also be recovered for the regeneration of (NH4)2SO4 and (NH4)2CO3. This study provides a feasible technology for green recycling of spent lead paste.

Durable CO2 conversion in the proton-exchange membrane system.

Electrolysis that reduces carbon dioxide (CO2) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future1-6. However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO2 precipitates as carbonate, and this limits carbon utilization and the stability of the system7-12. Strategies such as physical washing, pulsed operation and theuse of dipolar membranes can partially alleviate these problems but do not fully resolve them11,13-15. CO2 electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution16-18. Herein we develop a proton-exchange membrane system that reduces CO2 to formic acid at a catalyst that is derived from waste lead-acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO2 reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO2 at a current density of 600 mA cm-2 and cell voltage of 2.2 V and is shown to operate continuously for more than 5,200 h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.

Highly dispersed Ir/Fe nanoparticles anchored at nitrogen-doped activated pyrolytic carbon black as a high-performance OER catalyst for lead recovery.

The use of a methanesulfonic acid (MSA) electrolytic system is recommended as a green method for hydrometallurgical recovery of metallic Pb from waste lead-acid batteries (LABs), contributing to the sustainable protection of the ecosystem. Nevertheless, the system's high energy consumption is a current issue due to the substantial overpotential of the oxygen evolution reaction (OER) and competitive anodic oxidation of Pb2+. Herein, we propose an IrFe/nitrogen-doped pyrolytic carbon black (IrFe/NCBp) composite as a novel OER catalyst for the MSA electrolytic system, which demonstrates advanced OER catalytic efficiency and selectivity for H2O oxidation. This can be ascribed to the catalyst's thoughtful design, which enhances the number and uniformity of Ir and Fe species via increasing the specific surface area and employing NCBp as a sustainable substrate. The optimized IrFe/NCBp composite exhibits superior OER performance, with a low 252 mV@10 mA cm-2 overpotential and a 62 mV dec-1 Tafel slope, and excellent durability in a 1 M MSA electrolyte for 30 h operation compared to commercial Ir/C. In contrast to carbon paper (CP) and commercial Ir/C anodes, the anodic reaction of IrFe/NCBp is primarily OER-driven (97%) in 1 M MSA and 0.2 M Pb2+ electrolyte for Pb recovery. This effectively circumvents the high potential oxidation of Pb2+ into PbO2, reducing the electrolytic voltage to 488 kWh for the recovery of 1 ton Pb metal. This work provides a green, low-carbon footprint solution for the MSA electrolytic system, thereby promoting the commercialization of the hydrometallurgical Pb recovery.

A clean process for liquid-phase synthesis of α-PbO based on the selective leaching of lead sulfate from spent lead paste

In the recycling process of waste lead-acid battery paste, the traditional hydrometallurgical process of recovering α-PbO as a product presents the issues of the high concentration of alkali and the waste alkaline solution cannot be recycled. This study seeks a clean process for the liquid-phase synthesis of α-PbO based on the selective leaching of lead sulfate from spent lead paste. The pre-treated spent lead paste was initially leached with a sodium acetate solution to obtain a lead acetate solution. The leaching rate of PbSO4 in the leaching process was 99.87%. Metal impurities such as Fe and Ba could be removed. Then the lead acetate solution was mixed with NaOH particles to synthesize α-PbO. The purity of α-PbO obtained could be reached above 99.99% when the molar ratio of M(nOH-/Pb2+) was 3:1, the reaction temperature was 85 ℃, and the reaction time was 40 min. Meanwhile, a reaction pathway was also proposed in which β-PbO could be converted to α-PbO rapidly at low alkali concentrations. Furthermore, the recirculation process of the waste alkaline solution did not result in the accumulation of metal impurities and did not affect the purity of the α-PbO. The non-recyclable waste alkaline solution could be used to prepare sodium acetate solutions and sodium sulfate by-products. This study provides a feasible method for green recycling of spent lead paste.

Energy-saving recovery of lead from waste lead paste via in-situ hydrometallurgical reduction and electrochemical mechanism

The reasonable prudent disposal of secondary lead resources including waste lead-acid batteries has become a growing concern to prevent the adverse impacts. Herein, a facile zero-emission hydrometallurgical reduction approach is proposed for the recovery of spent lead paste (SLP) possessing energy-saving and high current efficiency merits. The effect of activated carbon (AC) additives on lead recovery efficiency, desulfurization efficiency, cathode current efficiency, and energy consumption was investigated during the hydrometallurgical reduction of SLP. The introduction of AC promotes the current efficiency and shortens the electrolysis time, which contribute to the diminution of the whole energy consumption. Especially, the specific energy consumption of hydrometallurgical reduction drops to 483.5 kWh t–1 with 2.0% AC from the initial 596.6 kWh t–1. Notably, the nucleation mechanism of lead on the SLP cathodes all follows three-dimensional instantaneous growth with the diffusion control. Moreover, the SLP plates after hydrometallurgical reduction could be directly employed as the negative electrodes of lead-carbon batteries, avoiding the formation stage. The electrochemical hydrometallurgical reduction with carbon additives presents a promising strategy for enabling zero emissions, low energy consumption operation of SLP recovery and reutilization.

A photodetector fabricated from 2H-PbI2 micro-crystals recycled from waste lead acid batteries.

Recycling Pb from lead acid batteries is rather important in environmental protection, but current strategies need a high temperature or produce secondary pollution. Herein, we present a green reactant recycling method to synthesize PbI2 micro-crystals by extracting the Pb from waste lead acid batteries. Systematical characterizations indicate that the as-prepared PbI2 micro-crystals show high purity, high crystal quality with a 2H-hexagonal crystal structure, and excellent optical properties with a bandgap of 2.3 eV. Based on the recycled 2H-PbI2 micro-crystals, a symmetrically structured ITO/PbI2/ITO photodetector is fabricated. Under 10 V bias voltage, the device reveals a distinct photo-response to UV-visible light and superior performance, with a dark current of 1.06 nA, an on-off ratio of 103, a responsivity of 15.5 mA/W, and a detectivity of 4.7 × 1010 Hz1/2 W-1. In addition, the photodetector also exhibits relatively rapid response speeds of 69 ms (rise time) and 64 ms (decay time). Our study provides an innovative and green strategy for producing a UV-visible photodetector based on recycled lead acid batteries, which is significant in environmental protection and the recycling economy.

Recycling lead from waste lead-acid batteries by the combination of low temperature alkaline and bath smelting

Recycling lead from waste lead-acid batteries has substantial significance in environmental protection and economic growth. Bearing the merits of easy operation and large capacity, pyrometallurgy methods are mostly used for the regeneration of waste lead-acid battery (LABs). However, these processes are generally operated at the temperature higher than 1300 °C. To shorten the energy consumption, a novel pyrometallurgy process which consisted of low temperature alkaline and bath smelting was proposed in this work. The reduction of lead and smelting of slag system are the key factors determine the energy consumption. Thermodynamic calculation suggested that the addition of Na2CO3 can make the reduction of PbSO4 spontaneously at the temperature higher than 288 °C (PbSO4 → PbCO3 → PbO → Pb), while direct reduction of PbSO4 necessitated the temperature higher than 1499 °C (PbSO4 → PbO → Pb). To achieve the efficient reduction of PbSO4, the molar ratios of C/PbSO4 and Na2CO3/PbSO4 should be higher than 0.5 and 1.0, respectively. Meanwhile, a new smelting system (i.e., FeO-SiO2-CaO-Na2O) was established in the presence of Na2CO3. Phases with low melting temperatures, such as NaFe2O3, Na2FeSiO4, Na2Ca2Si2O7, Na14Fe6O16 and Na0.5FeO2, were formed. The melting temperature of Fe-Si-Ca-Na system was lowered to 1050 °C at the mass dosage of Na2CO3 at 30%. Recovery of lead under various reduction conditions were systematically evaluated. Under optimum operational conditions, i.e., the dosages of C and Na2CO3 at 10% and m(actual)/m(theory) ratio of 1.3 (all in mass), smelting temperature of 1050 °C, and smelting time of 75 min, respectively, the lead recovery efficiency reached >98.0%. Moreover, this method has been successfully applied for the industrial recovery of lead at the scale of 200, 000 tons annually since 2019. Taken together, this method is robust for recovery of lead from the waste LABs and is helpful for building the resource-conserving society.

Green hydrometallurgical extraction of metallic lead from spent lead paste in the methanesulfonic acid system

As the mainstream process for recycling waste lead-acid battery paste to produce metallic lead ingots, pyrometallurgical smelting generally suffers from disadvantages such as high energy consumption, lead vapor and sulfur dioxide emissions. Hydrometallurgical extraction has received widespread attention because of its energy-saving and environmentally-friendly features. An innovative and efficient process for the hydrometallurgical recovery of lead paste was presented in this paper. In order to significantly improve the leaching efficiency of lead, PbSO4 in the lead paste was firstly converted into acid-soluble Pb3(CO3)2(OH)2 or NaPb2(CO3)2OH in Na2CO3 solution. At the same time, the insoluble PbO2 was reduced to PbO by the addition of Na2SO3. The pretreated product was then leached in MSA solution to obtain the lead-containing leachate, which was finally electrodeposited to produce lead deposits and to regenerate MSA. Under the optimized conditions, a dense and flat lead plate (purity greater than 99.99 %) could be obtained and the total lead recovery ratio in the whole process can reach 95.28 %. The cathode current efficiency and specific energy consumption in the lead electrodeposition procedure were 99.31 % and 598.91 kWh/t Pb, respectively. The electrolyte waste could be returned to the leaching process as the leaching agent. In contrast to the traditional fluorosilicate/fluoroborate and chloride systems, the environmentally-friendly MSA system with high lead solubility and low volatility, has promising applications in the field of lead hydrometallurgy.

Study on the Factors Affecting Consumers’ Participation in Regulated Recycling of Waste Lead-Acid Batteries: Practice Research from China

In China, the world’s largest producer and consumer of lead-acid batteries (LABs), more than 3.6 million tons of waste lead-acid batteries (WLABs) are generated every year, yet only 30% of them can be recycled in a well-regulated manner, while the remaining 70% are recycled through informal channels, resulting in serious waste of resources and environmental pollution. More than half of the country’s LAB consumers are e-car and e-bike owners. Based on the theoretical model of unified theory of acceptance and use of technology (UTAUT), this study examines and investigates the factors that affect consumers’ participation in the regulated recycling of WLABs and finds that consumers’ performance expectancy, social influence, and facilitating conditions can significantly increase their willingness to participate in regulated recycling, while effort expectancy can reduce such willingness. In addition, this paper also includes an analysis of moderating variables such as age and education. Finally, the paper points out the current lack of consumer-oriented recycling management measures in China and proposes policy recommendations in three aspects: system, channel, and incentive ones, to provide references for promoting the regulated recycling and sustainable use of WLABs.

An innovative synergistic recycling route of spent lead paste and lead grid based on sodium nitrate reuse

Hydrometallurgical route has been widely studied for its clean and controllability in recovering waste lead-acid battery. However, the current challenges are to reduce chemicals consumption and enhance the economic benefit. Therefore, we presented a sustainable approach for preparing lead oxide from the spent lead grid and lead paste based on sodium nitrate reusing. Results showed that the process indirectly and mildly completed the atomic economic reaction between lead and lead dioxide by sodium nitrate, dramatically reducing the reagents consumption. The reaction rate of the process was depended on the interfacial chemical reaction between lead grid and sodium nitrate. Through controlling the thermodynamic conditions, 99.53% of zero-valent lead (lead grid) was transformed into the layered orthogonal β-lead oxide with merely 0.0494% impurities, and 99.79% of tetravalent lead (lead dioxide in the lead paste) was converted into divalent lead (lead sulfate) in sulfuric acid solution. Afterwards, the lead sulfate was desulfurated followed by thermal decomposition, generating the rod-shaped tetragonal α-lead oxide with only 0.0233% impurities. Moreover, the products β-lead oxide and α-lead oxide used in batteries as anode materials showed excellent electrochemical performance with 482 and 518 charge/discharge cycles, respectively. Additionally, the pilot experiments proved the technological and economic feasibility of the process with a profit of $667.81/ton lead oxide. These results provide an economical and eco-friendly method for synergistically recycling waste lead grid and lead paste.

Research on the evaluation method of the business model for the recycling of hazardous waste in power grid

Hazardous wastes in power grids include waste transformer oil and waste lead-acid batteries, etc. Due to the problems of extremely large number of points, wide distribution, and small number of units, coupled with differences in hazardous waste recycling technologies, policies, and markets in various regions, so Possible business models need to be listed and evaluated. This paper establishes an evaluation index system for the business model of hazardous waste recycling, and uses the TOPSIS method to evaluate five feasible business models. The evaluation results will help relevant departments of power grid companies at all levels to formulate recycling strategies according to the characteristics of hazardous waste recycling, so as to facilitate the recycling and reuse of hazardous wastes.

Preparation of composite cathode material by using the extracted lead (Pb) of waste lead acid battery for LT-SOFC

The extraction of Pb from the waste lead acid batteries offers the conservation of energy resources and reduction of pollution load in the environment. The recycling of waste lead acid batteries than discarding by conventional methods is the best way. In the present studies, for LT-SOFC, three composite cathode materials (Pb0.1Fe0.4Co0.5O4-δ, Pb0.2Fe0.3Co0.5O4-δ and Pb0.3Fe0.2Co0.5O4-δ) were produced by extracting Pb from the waste lead acid batteries, cobalt nitrate [Co(NO3)3.6H2O] and iron nitrate [Fe(NO3)3.9H2O] using standard solid state reaction method. Thermal stability, morphological and structural characteristics were studied by TGA, SEM and XRD analyses. FTIR spectra were used to investigate the types of metal oxide bonding in the prepared ceramic composite cathode materials. Fuel cell testing and DC four probes were used to investigate electrochemical properties. The measurement of average crystalline size of the composites was found to be in the range of 12–37 nm.Scanning electron microscopy (SEM) images showed that composite materials are porous and suitable to diffuse the gases. The maximum conductivities of 1.6 Scm−1, 2.05 Scm−1 and 2.6 Scm−1 have been obtained for Pb0.1Fe0.4Co0.5O4-δ, Pb0.2Fe0.3Co0.5O4-δ and Pb0.3Fe0.2Co0.5O4-δ, respectively. At 600 °C, the high OCV (0.95V) and the maximum power density (439 mW/cm2) have been achieved using hydrogen as the fuel. Lower value of activation energy (0.36ev) of Pb0.3Fe0.2Co0.5O4-δ confirms that it is the efficient material to convert electrochemically hydrogen fuel into valuable electricity.

Analysis of a more sustainable method for recycling waste lead batteries: Surface renewal promotes desulfurization agent regeneration.

The traditional sodium desulfurization process for waste lead-acid batteries is beneficial to the environment; however, it is limited by poor economic viability as the cost of desulfurizer is much higher than the value of desulfurization by-products. This study proposes a new closed-loop pre-desulfurization process for lead paste, which consumes only lime as the indirect desulfurizer, produces sodium sulfate as a by-product, and regenerates sodium hydroxide as the direct desulfurizer. The concentration of prepared sodium hydroxide reached 2.57mol/L when the reaction was conducted at room temperature for 2.0h, with a sodium oxalate: calcium oxide molar ratio of 1:1.3, a CaO: water mass ratio of 1:6, and magnetic stirring at 600rpm. Cost estimation and economic analyses were also conducted. The cost of lead paste generated by this new pre-desulfurization process was 37.62 dollars/ton lower than traditional high-temperature smelting, and 44.42 dollars/ton lower than direct sodium pre-desulfurization. Thus, this process provides a practical and feasible clean recycling method for waste lead-acid batteries with significant environmental and economic benefits.

Analysis on pollution prevention and control of waste lead battery recycling process

From the perspective of recycling, waste lead-acid batteries have very objective utilization value. However, from the perspective of environmental protection, waste lead-acid batteries contain many pollutants, which will cause serious pollution and damage to the environment if not handled properly. Containing lead, not only has a very high collection value, also is likely to lead pollution and poisoning accidents caused by improper operation, cause a threat to people’s life and health, therefore, this text set about from the pollution source analysis, through the way of recycling and pollution prevention and control technology were analyzed, and aims to take certain measures to protect the environment, protect health.

Impact of waste slag reuse on the sustainability of the secondary lead industry evaluated from an emergy perspective

Waste slag (WS) derived from the pyrometallurgical process of waste lead-acid battery (LAB) is becoming a potential contributor to environmental pollution. Therefore, WS treatment or disposal should be considered an integral part of waste LAB treatment systems to comprehensively analyze the sustainability of secondary lead industry. Given that emergy analysis (EmA) can evaluate all forms of energy, materials, and human services on a common basis by converting them into equivalents of one form of energy, our study proposes an emergy-based approach and several improved indicators. Unlike traditional emergy indicators, the output emergy and waste emergy in our approach were added into an improved emergy indicators. The improved indicators also converted emission impacts into equivalent emergy associated with economic activities, including the emergy of ecological services, emergy loss of affected natural resources, emergy losses associated with human health damage and land occupation. Next, four scenarios as study cases were evaluated using the proposed approach and indicators. Our study found that 1) the improved emergy indicators are more rigorous than their traditional counterparts; 2) although the reuse of WS raises the disposal costs (scenario C and scenario D), it can improve the environmental performance of waste LAB treatment systems, thereby greatly improving system sustainability; finally, the proposed approach can help policy-makers make decisions and guide enterprises to improve the overall performance of waste LABs treatment systems.

Vacuum decomposition thermodynamics and experiments of recycled lead carbonate from waste lead acid battery

Lead acid batteries have been widely used in different fields, so abundant waste lead acid battery was generated. Waste lead acid battery is regarded as a toxic material due to the metallic lead and the lead paste compounds. Once lead and its compounds enter the human body and the environment, which will cause serious threats. At present, the waste lead acid batteries are mainly recovered in the form of metal lead, which has many problems. Thus, this paper put forward a novel technology to recycle waste lead acid battery. Vacuum thermal decomposition was employed to treat recycled lead carbonate from waste lead acid battery. Thermodynamics analysis and experiments were finished from the reaction free energy of lead carbonate decom-position and vacuum furnace. The results showed that the recycled lead carbonate began to be decomposed when the temperature reached 250?C. Above 340?C, most of intermediate PbCO3?2PbO were converted to red ?-PbO and then transformed to yellow ?-PbO when the temperature was raised further to 460?C. Furthermore, the study provided the fundamental data for the preparation of ?-PbO and ?-PbO in vacuum, which also demonstrated a new way for the reuse of spent lead acid battery resource and an outlook of sustainable production.