Cobalt recovery from the stripping solution of spent lithium-ion battery by a three-dimensional microbial fuel cell

https://doi.org/10.1016/j.seppur.2019.01.002Get rights and content

Highlights

  • A three-dimensional microbial fuel cell was constructed to remove and recover Co.

  • The pH in catholyte was controlled by restraining the protonic electromigration.

  • Effects of carbonization temperatures on the systemic performance were analyzed.

  • BE system was optimized based on the orthogonal results to maximize results.

  • The reaction mechanisms in the 3D system were specifically discussed and tested.

Abstract

Cobalt (Co) recycling from the spent LIBs not only favors the ecological protection also meets the supply chain of Co in the international market. In this research, a three-dimensional microbial-fuel-cell (3D-MFC) two-chamber system with granular activated carbon (GAC) microelectrodes was constructed to remove and recover Co from the stripping cobalt sulfate solution. The 3D bio-electrochemical (BE) system exhibited the largest voltage output and power production at 12th day during the acclimation, achieving the maximum power densities (W/m3) of 6.24, 10.29, 14.52, 12.59, and 8.78, respectively. The GAC prepared at 500 °C achieved highest removal and recovery efficiencies of Co in the 3D-MFC system. The maximum removal efficiency of 98.47%, the recovery efficiency of 96.35%, the power density of 11.34 W/m3, and the columbic efficiency of 28.74% were obtained in the orthogonal experiments. The influence of the operating time on the removal and recovery of Co was more obvious than the electro-output of the system. The addition of ammonium carbonate to the 3D-MFC systems clearly increased the precipitation of Co. The stacking of GAC particles in MFC had strengthened the adsorption of Co ions by intensifying the acidic-alkaline pathways during the 3D BE process. The removal and recovery of Co ions from the stripping solution in the 3D-MFC experiments were mainly achieved by the electromigration, electrostatic adsorption of GAC, and chemical precipitations of cobalt hydroxide and cobalt carbonate. A continuous process was suggested for the 3D-MFC application integrating to the traditional recovery procedure of Co from the spent LIBs at the pilot scale.

Introduction

The industry of lithium ion batteries (LIBs) has been rapidly propelled forwards with a tremendously rising demand from the emerging market (e.g., smart-phones, tablet PCs, and new energy vehicles) in recent years [1], [2]. The spent LIB is commonly categorized to the hazardous solid wastes, majorly consisting of heavy metals (HMs), organic chemicals, and plastics. An inappropriate disposal of spent LIBs can result in serious environmental problems [3], [4], [5]. Currently, the active materials identified as cathode in LIBs include LiCoO2, LiFePO4, LiNiO2, and LiMn2O4, etc. The utility of the layered LiCoO2 has occupied the highest rate in the market [6], [7], [8], [9]. The recycling (or recovery) of Co element from spent LIBs not only benefits the habitat protection also offsets the inadequate supply of Co in the world. The technologies employed for the recycling process of spent LIBs are commonly categorized to pyrometallurgy and hydrometallurgy [10], [11], [12], [13], [14]. The hydrometallurgical methods are more preferably adopted due to the advantages of lower energy-expenditure, easier conduction, and smaller gas emission [15], [16]. However, the high-dependency on some specified chemical regents are seemingly inevitable for some traditional hydrometallurgical techniques, such as solvent extraction, pH-controlling precipitation and leaching, etc. It is quite meaningful to explore some appropriate methods to progressively handle or relieve the issues facing at present [10], [17], [18], [19].

One novel promising method for the setting goal is the employment of microbial fuel cells (MFCs). Microorganisms are applied in MFC to anaerobically decompose (i.e., oxidize) biodegradable organic materials to drive the bio-electrochemical (BE) system [20], [21], [22]. The electrons are bio-catalytically transferred from the organics to anode surface and further to cathode through microbial respiring metabolism and external circuit [23], [24], [25]. The potential differences between the electrodes render both cations and anions electro-migratable [26]. The accumulation of target contaminants in a specified area can be fluently achieved by the electromigration and electrochemical reduction in combination [27]. However, the electrochemical reduction of Co is thermodynamically unfavorable due to its lower potential in contrast to the anodic potential values. Therefore, the removal of Co is reassigned to the traditional chemical precipitation [28], [29], [30], [31]. The pH ascension combining with the enhanced adsorption in catholyte becomes essential in achieving the removal of Co from the stripping liquor in MFC systems.

A three-dimensional (3D) electrochemical process integrates the charged particle electrodes and the two-dimensional (2D) counterpart process, expanding the specific surfaces of the electrodes and shortening the mass-transferring distance [32], [33], [34]. Those polarized particles forming anode and cathode along a unified direction strengthen the conductivity and adsorption of contaminants and buffer the dramatic changes in the acid-alkali environments [35], [36]. As known, the 3D electrochemical system has been extensively studied in the treatments of various wastewaters based on its own advantages [36], [37], [38]. However, the construction of 3D BE system without external energy input (Power source) and its subsequent applications have scarcely been investigated. The definition of 3D BE model have not been mentioned in the environmental domain until now.

In this study, a 3D-MFC system was originally designed aiming at substituting the chemical precipitation regents for the effective recovery of divalent Co cations (i.e., Co(II)) from the stripping solutions of CoSO4. The homemade granular activated carbon (GAC) using as both adsorbent and microelectrode was tightly stacked closing to the cathode in order to enhance the electrostatic adsorption and positively induce the continuous precipitation of Co(II) ions. The pH environments in the catholyte were reasonably controlled through restraining the electromigration of the biologically generated protons in the anode chamber. The effects of carbonization temperatures on the removal and recovery of Co and the electric output performances of BE system were comprehensively investigated based on the electrical results. The optimized combination of the running parameters was determined based on the orthogonal results of indicators. The influence of (NH4)2CO3 concentration on the physical characteristics and experimental indicators was studied in final to consummate the preparation of Co3O4 powders. The reaction mechanisms in the 3D-MFC system for the removal and recovery of Co were specifically discussed and tested by measurements of morphologies and mineral phases of GAC particles before and after experiments. This research quantitively testifies the feasibility of a 3D-MFC platform for the resource recycling and comprehensively explores the operating conditions influencing the running performance of 3D electrochemical system. The experimental results in this study will support the application of 3D-MFC platform constructing for recovery of other precious cations from the spent LIBs.

Section snippets

The preparation of CoSO4 solution and the activated carbon

The cathode materials were obtained from the spent LIBs through manual dismantling and ultrasonic cleaning procedures. The ultrasonic conditions were set at 60 °C, 160 W, and 15 min. The leaching experiments were conducted by stirring cathode materials with 2 M of H2SO4 and 5 vol% of H2O2 (30%) at a ratio of solid to liquid (S-L) of 1:20 mg/L, 75 °C and 250 rpm over 30 min. The metal ions of Al, Fe, and Cu were recovered using NaOH (10%) and Na2S in the form of hydroxide-precipitations with pH

Acclimation of inoculum

The changes in the indicators for the performance of 3D-MFC system during the acclimation of inoculum are shown in Fig. 2a–d. The electrogenic acclimation tests were conducted to guarantee the biofilm formation, the reproduction of the electroactive microorganisms, and the bio-oxidation of acetate before the Co(II)-removal process [43], [44]. The sulfuric acid solution with the initial pH of 4 and AC particles prepared at 300 °C was adopted as the catholyte and the cathodic stacking material,

Conclusions

The maximum power output was obtained at 12th d during the acclimation. However, an unreasonable prolongation in terms of setup would cause potential inhibition to microorganisms and significantly increase the internal resistances and over-potentials. Besides, the carbonization temperatures for the preparation of GAC particles also affected the running performance of the 3D-MFC platform. The increases in the anodic temperatures improved the electrogenic activities of microorganisms but

Acknowledgements

The research is not funded by any organization.

Declaration of interests

The authors have no competing interests to declare.

References (60)

  • H. Ciftci et al.

    Biohydrometallurgy in Turkish gold mining: first shake flask and bioreactor studies

    Miner. Eng.

    (2013)
  • D. Dutta et al.

    Close loop separation process for the recovery of Co Cu, Mn, Fe and Li from spent lithium-ion batteries

    Sep. Purif. Technol.

    (2018)
  • A.G. Guezennec et al.

    Co-processing of sulfidic mining wastes and metal-rich post-consumer wastes by biohydrometallurgy

    Miner. Eng.

    (2015)
  • Y. Asensio et al.

    Influence of the ion-exchange membrane on the performance of double-compartment microbial fuel cells

    J. Electroanal. Chem.

    (2018)
  • W.F. Cai et al.

    Investigation of a two-dimensional model on microbial fuel cell with different biofilm porosities and external resistances

    Chem. Eng. J.

    (2018)
  • T. Huang et al.

    Electrokinetic removal of chromium from chromite ore-processing residue using graphite particle-supported nanoscale zero-valent iron as the three-dimensional electrode

    Chem. Eng. J.

    (2018)
  • A.V.M. Silveira et al.

    Recovery of valuable materials from spent lithium ion batteries using electrostatic separation

    Int. J. Miner. Process.

    (2017)
  • Z. Takacova et al.

    Cobalt and lithium recovery from active mass of spent Li-ion batteries: theoretical and experimental approach

    Hydrometallurgy

    (2016)
  • A. Chmayssem et al.

    Scaled-up electrochemical reactor with a fixed bed three-dimensional cathode for electro-Fenton process: application to the treatment of bisphenol A

    Electrochim. Acta

    (2017)
  • L. Daneshvar et al.

    Electrochemical determination of carbamazepin in the presence of paracetamol using a carbon ionic liquid paste electrode modified with a three-dimensional graphene/MWCNT hybrid composite film

    J. Mol. Liq.

    (2016)
  • T. Huang et al.

    Operating optimization for the heavy metal removal from the municipal solid waste incineration fly ashes in the three-dimensional Chock tar electrokinetics

    Chemosphere

    (2018)
  • L.J. Jiang et al.

    Recovery of flakey cobalt from aqueous Co(II) with simultaneous hydrogen production in microbial electrolysis cells

    Int. J. Hydrogen Energy

    (2014)
  • L. Huang et al.

    Cobalt recovery with simultaneous methane and acetate production in biocathode microbial electrolysis cells

    Chem. Eng. J.

    (2014)
  • L.P. Huang et al.

    Complete cobalt recovery from lithium cobalt oxide in self-driven microbial fuel cell – microbial electrolysis cell systems

    J. Power Sources

    (2014)
  • S. Rout et al.

    Enhanced energy recovery by manganese oxide/reduced graphene oxide nanocomposite as an air-cathode electrode in the single-chambered microbial fuel cell

    J. Electroanal. Chem.

    (2018)
  • J.A. Modestra et al.

    Electro-fermentation of real-field acidogenic spent wash effluents for additional biohydrogen production with simultaneous treatment in a microbial electrolysis cell

    Sep. Purif. Technol.

    (2015)
  • E. Garcia-Bordeje et al.

    Parametric study of the hydrothermal carbonization of cellulose and effect of acidic conditions

    Carbon

    (2017)
  • X.P. Chen et al.

    Separation and recovery of metal values from leaching liquor of mixed-type of spent lithium-ion batteries

    Sep. Purif. Technol.

    (2015)
  • S. Monasterio et al.

    Electrochemical removal of microalgae with an integrated electrolysis-microbial fuel cell closed-loop system

    Sep. Purif. Technol.

    (2017)
  • G.D. Bhowmick et al.

    Bismuth doped TiO2 as an excellent photocathode catalyst to enhance the performance of microbial fuel cell

    Int. J. Hydrogen Energy

    (2018)
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