New Perspectives for Electrodialytic Remediation

Electrodialytic remediation has been widely used for the recovery of different contaminants from numerous matrices, such as, for example, polluted soils, wastewater sludge, fly ash, mine tailing or harbour sediments. The electrodialytic remediation is an enhancement of the electrokinetic remediation technique, and it consists of the use of ion-exchange membranes for the control of the acid and the alkaline fronts generated in the electrochemical processes. While the standard electrodialytic cell is usually built with three-compartment configuration, it has been shown that for the remediation of matrices that require acid environment, a two-compartment cell has given satisfactory removal efficiencies with reduced energy costs. Recycling secondary batteries, with growing demand, has an increasing economic and environmental interest. This work focusses on the proposal of the electrodialytic remediation technique as a possible application for the recycling of lithium-ion cells and other secondary batteries. The recovery of valuable components, such as lithium, manganese, cobalt of phosphorous, based on current recycling processes and the characterization of solid waste is addressed.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Electrodialytic Recovery of Cobalt from Spent Lithium-Ion Batteries

Contribución en congreso científicoRecycling lithium-ion batteries has an increasing interest for economic and environmental reasons. Disposal of lithium-ion batteries imposes high risk to the environment due to the toxicity of some of their essential components. In addition to this, some of these components, such as cobalt, natural graphite and phosphorus, are included in the list of critical raw materials for the European Union due to their strategic importance in the manufacturing industry. Therefore, in the recent years, numerous research studies have been focused on the development of efficient processes for battery recycling and the selective recuperation of these key components. LiCoO2 is the most common material use in current lithium-ion batteries cathodes. In the current work, an electrodialytic method is proposed for the recovery of cobalt from this kind of electrode. In a standard electrodialytic cell, the treated matrix is separated from the anode and the cathode compartments by means of ion-exchange membranes. A cation-exchange membrane (CEM) allows the passage of cations and hinders the passage of anions, while the behaviour of anion-exchange membrane (AEM) does the opposite. A three-compartment electrodialytic cell has been designed and assembled, as depicted in the figure. In the central compartment, a suspension of LiCoO2 is added. Different extracting agents, such as EDTA, HCl and HNO3, are tested to enhanced the dissolution and the selective extraction of the target metal. Dissolved cobalt-containing complexes migrate towards the cathode or the anode compartments depending on the ionic charge of the complexes. While cobalt extraction via extracting agents is an expensive treatment, as it requires the constant addition of chemicals, an efficient electrodialytic cell could allow the recirculation of the extracting agents and the economical optimization of the process.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Sequential extraction procedure: a versatile tool for environmental research

The sequential extraction procedure as a tool to assess the environmental risk of metals in solid matrices has been widely studied. In this work, other promising application of these methods is proposed: the evaluation of the recoverability of critical raw materials from a solid matrix. To this aim, the normalized sequential extraction procedure BCR was applied to a real contaminated soil from the south of Spain. In addition to this, the influence of the incomplete dissolution of carbonates contained in the soil on the fractionation results has been also studied. The high percentage of metal in the most mobile fractions suggested the potential use of the solid matrix as secondary source. The use of this approach together with environmental and economic feasibility studies would be an approach toward the circular economyThis work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. The University of Malaga is acknowledged for the financial support in the postdoctoral fellowship of Villen-Guzman. Cerrillo-Gonzalez acknowledges the FPU grant obtained from the Spanish Ministry of Education. Paz-Garcia acknowledges the financial support from the program “Proyectos I+D+i en el marco del Programa Operativo FEDER Andalucía 2014-2020”, No. UMA18-FEDERJA-279

Electrodialytic Treatment of Secondary Batteries Cathodes

The interest for reusing and recycling secondary batteries is increasing, driven by both economic and environmental reasons. Lithium-ion batteries are among the main energy storage devices more popular in portable electronic and there are being used more every year in the field of electric transportation. The growing demand for rechargeable batteries entails an increase in the attention paid to the recycling of spent batteries due to the toxicity of some of their essential components. Furthermore, some of these components, such as cobalt, natural graphite and phosphorus, are included in the list of critical raw materials for the European Union due to their strategic importance in the manufacturing industry. Therefore, the development of new technologies to selectively recover these key components should be addressed. In this work, an electrodialytic method is applied to real battery wastes previously submitted to a pre-treatment process (Figure 1). We focused on the extraction of Co and Li from spent cathodes, in combination with acid-extraction and different oxidation/reduction environments. The optimization of some of the most relevant operating parameters, such as cell design, selection of enhancing agent and current density has been carried out according to the lithium-ion batteries waste characteristic. Results indicate that the electrodialytic method could be a useful technique for the selective extraction of Li and Co from spent batteries. Furthermore, the deposition of Co at the cathode surface may be optimized to separate the cations at the catholyte, for a direct reincorporation in the manufacturing chain.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors acknowledge the financial support from the "Plan Propio de Investigación de la Universidad de Málaga" with project numbers, PPIT.UMA.D1, PPIT.UMA.B1.2017/20 and PPIT.UMA.B5.2018/17. This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045

A Model for Electrodialytic Treatment of Lithium-Ion Batteries

New recycling processes for secondary batteries are needed to achieve sustainable use of natural resources. Indeed, many components in lithium ion batteries, such as cobalt and graphite, are in the European Union’s “Critical Raw Materials” list. Electrodialytic treatment of disposed lithium-ion batteries is a pioneer proposal for the selective recovery of some of these relevant elements. In this work, a model for the electrochemical technology of disposed batteries implemented using COMSOL Multiphysics is presented. The main aim of this model is the optimization of the extraction of valuable components from spent batteries and the prediction of experimental results, which entails a better understanding of the different process involved. The model is based on the Nernst-Planck- Poisson system of equations coupled with the local chemical equilibrium conditions. The model uses multi-scale discretization of the different components; including the assumed well-stirred compartments, the ion-exchange membranes and the diffuse double-layer at the surface of the membranes. Different cell configuration has been tested, and results were compared to experimental data for model validation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors acknowledge the financial support from the "Plan Propio de Investigación de la Universidad de Málaga" with project numbers PPIT.UMA.D1, PPIT.UMA.B1.2017/20 and PPIT.UMA.B5.2018/17. This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045

Improving Cr (VI) Extraction through Electrodialysis

A laboratory study has been carried out to determine the feasibility of in situ remediation of chromium (VI) contaminated soil using electrodialysis. In a classic setup, this technique implies the application of a low intensity direct current to the soil, which is separated from the electrode compartments by ion-exchange membranes. If the pollutants are ionic compounds, they can be forced to migrate to the oppositely charged electrode by electro-migration. Membranes selectively impede the flow of ions in the electrode compartments back to the soil. If a metal species is naturally present as an anion, mobilization from the soil at alkaline pH can be realized and, at the same time, the mobilization of other metal cations that occur at low pH can be minimized. Experiments have been carried out with clayey soils (kaolinite clay and soil clay mixtures) that have been characterized and then contaminated by mixing with a potassium dichromate solution for several days. Initial Cr (VI) content ranges from 500 to 4000 mg/kg. Treatment tests were carried out in an acrylic laboratory cells consisting of a central soil compartment and two electrode compartments located at both ends of the column. Dimensionally stable titanium electrodes coated with mixed metal oxides were placed in the electrode compartments. 0.01M Na2SO4 electrolytes were recirculated through them from two 1-liter deposits using a peristaltic pump. Two commercial ion exchange membranes separated the anolyte and catholyte compartments from the soil in the standard configuration. A programmable DC: power supply was connected to the electrodes and a computer for data acquisition.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors acknowledge the financial support from the "Plan Propio de Investigación de la Universidad de Málaga" with project numbers PPIT.UMA.D1; PPIT.UMA.B1.2017/20 and PPIT.UMA.B5.2018/17. This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045

Modeling of Electrodialytic Treatment of Lithium-Ion Batteries

Lithium-ion batteries are currently present in most portable electronic devices and their use is rapidly growing in the field of electric vehicles and renewable energy storage. Many components in lithium-ion batteries are toxic and/or environmentally hazardous. Furthermore, some of them are expensive and listed as critical materials in terms of supply-chain risk. Therefore, the need to improve the recycling techniques for lithium-ion batteries is becoming a priority. Herein, we describe and present a model for the electrodialytic treatment of disposed lithium-ion batteries. Electrodialysis is a separation process based on the use of electric fields and ion-selective membranes. The electrodialytic cell can be designed in different configurations, to enhance the selective extraction of the target products. In a standard electrodialytic cell, the treated matrix is separated from the anode and the cathode compartments by means of anion- and cation-exchange membranes respectively. However, depending on the ionic charge and the specific chemistry of the matrix, different cell designs can be used. In the present work, different possible configurations are explored for the optimization of the extraction of key valuable components from spent lithium-ion batteries, taking into account the chemical properties of the system depending on the chosen extracting agent and cell configuration. The model presented here is based on a set of differential and algebraic equations consisting of a Nernst-Planck based continuity equations for each of the chemical species involved in the process, coupled with the electroneutrality and the local chemical equilibrium conditions. The numerical solution is performed using COMSOL Multiphysics, and the simulation results are compared with experimental data for model validation.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec