Spent Li-ion Batteries Research Articles

Optimization Fungal Leaching of Cobalt and Lithium from Spent Li-Ion Batteries Using Waste Spices Candlenut

Lithium-ion battery (LIB) applications in consumer electronics nowdays are rapidly growing resulting the increase of batteries solid waste containing toxic and corrosive substances for the environment. On the other hand, the main active cathode components in LIB are Lithium and Cobalt, which are hazardous and limited in nature but are valuable metals. This study aims to use bio-hydrometallurgical techniques to recover heavy metals from LIB using microorganisms to avoid toxic waste from used solvents which are usually generated in conventional chemical leaching. Filamentous fungi have an important role in secreting citric acid and several organic acids to facilitate the dissolution of metal ions from the metal solids. Self-grown fungi, Aspergillus niger isolated from waste spices (Candlenut) was used as a leaching agent. Route based on fungal activity was evaluated to optimized the detoxification and metal recovery from spent LIB in various conditions (one-step, two-step and spent medium bioleaching) in 21 days of incubation. The quantitative result of XRF and EDX analysis of battery powder before and after bioleaching confirm that fungal activities are quite effective. The maximum recovery of both metals (Cobalt and Lithium) in leached liquor reached up to 72% analyzed using ICP-OES with the one-step leaching method. With respect due to the high metal recovery, fungal leaching has proven to be an easy and cost-effective green metallurgical method for recycling heavy metals in used LIBs.

Electrification and decarbonization of spent Li-ion batteries purification by using an electrochemical membrane reactor

The expanding electric vehicle market brings with it exponential growth in the use of lithium (Li)-ion batteries (LIB) for which a wave of spent LIB is expected to come within the next 5 to 10 years. Due to the economic and strategic value imbedded within the metals contained in LIB, different recycling technologies, including hydrometallurgy, pyrometallurgy and direct recycling, are under development. Being different from previous hydrometallurgical methods, which may have high chemical consumption and negative environmental impact, an electrochemical membrane reactor is designed and validated for the first time, to electrify and decarbonize the impurity removal process. This reactor electroplates copper (Cu) and electrochemically precipitates aluminum (Al) and iron (Fe) from simulated spent LIB leachates, by consuming only air, water, and electricity, and the impurities are reduced to <1 ppm. The purified leachate maintains 99.5 % of the nickel (Ni), 95.4 % of the cobalt (Co) and 99.14 % of manganese (Mn) from the original leachate solution, and then can be directly applied for cathode precursor synthesis. Additionally, the purification process doesn’t introduce extra impurity, and the reactor restoration process generates valuable by-product hydro sulfate (H2SO4). This electrochemical process can reduce the cost, because of the much less chemical consumption and the valuable by-product generation, and mitigates the waste emissions, because of no extra impurity introduced and no greenhouse gas (GHG) produced. The chemical precipitation method uses significant amount of NaOH, which induced GHG emission during the manufacturing process.

Oriented conversion of spent LiCoO2-lithium battery cathode materials to high-value products via thermochemical reduction with common ammonium oxalate

Recycling critical metals from spent Li-ion batteries (LIBs) is essential for the overall sustainability of future batteries. This study presents a refined thermochemical reduction-assisted water leaching approach to efficiently recover lithium and cobalt from spent LiCoO2 LIBs using ammonium oxalate as the only reducing agent. Through thermochemical reduction, LiCoO2 was converted to Li2CO3 (water-soluble) and metallic Co (water-insoluble). After leaching with water, 99.63% lithium and 99.82% cobalt were obtained as Li2CO3 and metallic Co, with 99.74% and 98.95% purity, respectively. The thermochemical mechanism revealed that the thermochemical process consists of two different stages of ammonium oxalate decomposition and controlled reduction. High purity of metallic Co products can be acquired by regulating the amount of ammonium oxalate. These findings can inspire environmentally friendly and value-added recycling of metals from spent LIBs.

Carbothermic reduction of LiCoO2 cathode material: Thermodynamic analysis, microstructure and mechanisms

Carbothermic reduction using secondary carbon materials such as graphite anode provides an option for recycling critical elements in the spent Li-ion batteries. In this study, carbothermic reduction of battery cathode material LiCoO2 using graphite as reductant was systematically investigated. The study included thermodynamic evaluation using the FactSage™ thermochemical modelling, isothermal high-temperature experimentation at 700–1100 °C under argon atmosphere, and detailed microstructure evolution analysis to establish the mechanisms of the reduction. The products from the reduction experiments were found to be Li2CO3, Li2O, and Co, and these corresponded well with the thermodynamic assessments. The overall reduction mechanism was evaluated to start with LiCoO2 decomposition followed by the reduction of cobalt oxide to form metallic cobalt. The results also suggest that reduction occurs indirectly through reduction by CO(g). The information generated in the study are useful for improvement and parameter optimization for high temperature recycling of Li-ion batteries.

Green recycling of spent Li-ion batteries by deep eutectic solvents (DESs): Leaching mechanism and effect of ternary DES

Spent Li-ion batteries (LIBs) contain large amounts of hazardous metals (Co, Ni, Li, and Mn) that cause environmental pollution and health risks. In this study, one ternary (choline chloride (ChCl):Urea: ethylene glycol (EG)) and two binary (ChCl: Urea and ChCl: EG) nontoxic deep eutectic solvents (DESs) were developed as environmentally friendly, cost-effective, and safe approaches for recycling of spent LIBs. FT-IR Analysis of DESs solvents showed that the ternary DES spectrum overlaps the spectra of ChCl:Urea and ChCl: EG. Therefore, the EG structure is stable in ChCl:Urea: EG. The leaching results indicated that temperature directly affects the extraction of valuable metals in the presence of all DESs. Among the three DES types, the ternary DES exhibits optimal extraction performance (Li:97%, Co:41%, Ni:40%, and Mn:34%). In addition, kinetic modeling was used to study the reaction mechanisms. The results showed that the mixed control model by shrinking core model (diffusion control and chemical reaction control) was the best model fitted to all data (coefficient of determination (R2) > 0.90). According to the Arrhenius equation, the activation energies for all valuable metals in the presence of all DESs are between 13 and 42 KJ/mol, reflecting a mixed control reaction.

Synergistic enhancement of metal extraction from spent Li-ion batteries by mixed culture bioleaching process mediated by ascorbic acid: Performance and mechanism

Pure and mixed cultures of microorganisms are used to leach spent Li-ion batteries (LIBs) to extract high-value metals. However, a low metal leaching efficiency is a general problem, hindering the commercialization of spent LIBs bioleaching. Therefore, a mixed culture bioleaching (MCB) process, mediated by ascorbic acid (AA), is proposed to promote the leaching of spent LIBs. Results show that the AA-MCB process leaches 94% Co and 95% Li at a pulp density of 20 g L−1, realizing 54% Co and 31% Li enhancement. Mass spectrometry analysis showed that a reduced bioleaching system is constructed by the mixed culture, AA, and AA products. In this system, bacteria promote LiCoO2 exposure on spent LIB surface by producing bioacid. Therefore, the refractory Co(III) easily reduces to soluble Co(II) by AA and its products, leading to the destruction of the crystalline structure of LiCoO2. Furthermore, bioacid facilitates easy leaching of Co and Li from structurally damaged LiCoO2. Ultimately, the AA-MCB process transforms spent LIBs from hazardous to general solid waste, exhibiting no biotoxicity to Escherichia coli growth. Therefore, bioleaching process intensification by adding a green organic reducing agent is a promising alternative for effective metal extraction from spent LIBs, enriching the current recycling technologies of spent LIBs.

Hydrometallurgical leaching and recovery of cobalt from lithium ion battery

The main aim of this work was to test the ability of an amino acid (i.e. glycine) to leach cobalt from Li ion batteries (LiBs). The process parameters namely temperature, pulp density and concentration of glycine were optimized for maximizing the leaching efficiency of cobalt from the cathodic material. Response surface methodology (RSM) was applied for determining the experimental conditions instead of using the traditional one factor at a time (OFAT) approach in order to ascertain the interaction effects between the different factors. Thus, the optimal leaching value based on RSM and maximum cobalt leaching potential from LiBs was obtained. The optimum values for the parameters were as follows; temperature = 74 °C, pulp density = 19.9 g/L and glycine concentration = 0.936 M. Under this optimum condition, the cobalt leaching efficiency was 61.8%, while a maximum leaching of 89.7% was achieved at the following conditions: temperature = 100 °C, pulp density = 13.8 g/L and glycine concentration = 1.24 M. Oxalic acid was used for recovering cobalt from the leaching solution by varying the pH and molar ratio of oxalic acid and cobalt ions. Cobalt recovery efficiencies were ∼ 88.0% at pH 7.0 and at oxalic acid to cobalt ion molar ratio of 2.5:1.0. • Glycine in the presence of H 2 O 2 leached Co from spent Li ion batteries. • A maximum of 89% of Co was leached by glycine from LiBs. • Co was selectively recovered using oxalic acid as precipitating agent. • More than 88% of soluble Co can be recovered as Co-oxalate precipitate.

Easy and Scalable Synthesis of NiMnCo-Oxalate Electrode Material for Supercapacitors from Spent Li-Ion Batteries: Power Source for Electrochromic Devices

Easy and Scalable Synthesis of NiMnCo-Oxalate Electrode Material for Supercapacitors from Spent Li-Ion Batteries: Power Source for Electrochromic Devices

Oxidation of glucose to glycolic acid using oxygen and pyrolyzed spent Li-ion battery electrode material as catalyst

A search for non-noble catalysts for biomass processing led to the discovery that pyrolyzed electrode coating of spent Li-ion batteries can be used as an excellent catalyst for oxidation of D-glucose to glycolic acid. New no/low-cost catalyst was prepared by pyrolyzing black electrode coatings of 18,650 Li-ion cells from a spent DELL 1525 laptop battery at 600 ºC. Catalyst was characterized using SEM, EDX and X-ray and was shown to contain lithium nickel manganese cobalt oxide (LiaNibMncCodOe) on carbon with Ni: Mn: Co 4.12: 2.10: 1.50. The catalytic activity of this material was evaluated for oxidation of D-glucose in aq. NaOH and water; glycolic, tartaric, malic, succinic and 2-hydroxybutaric acid were identified as key degradation products. The highest glycolic acid yield of 94% was obtained for oxidation of D-glucose under 3.4 Atm. oxygen, 120 °C, 2.0 h in 0.5 M aq. NaOH using 10 g catalyst/mol glucose.

Recovery of critical metals from spent Li-ion batteries: Sequential leaching, precipitation, and cobalt–nickel separation using Cyphos IL104

This study presents a novel recycling scheme for spent Li-ion batteries that involves the leaching of lithium in hot water followed by the dissolution of all transition metals in HCl solution and their separation using the ionic liquid Cyphos IL104. The parametric studies revealed that >84 % Li was dissolved while the cathode material was leached at 90 °C for 2 h. Approximately 98 % Li from the non-acidic solution was directly precipitated as Li2CO3 at a Li+:CO32− ratio of 1:1.5. The transition metals from the Li-depleted cathode mass were efficiently (>98 %) dissolved in 3.0 mol·L−1 HCl at 90 °C for a 3 h leaching process. Manganese from the chloride leach liquor was selectively precipitated by adding KMnO4 at a 1.25-fold higher quantity than the stoichiometric ratio, pH value 2.0, and temperature 80 °C. The remaining co-existing metals (Ni and Co) were separated from the chloride solution by contacting it with a phosphonium-based ionic liquid at an equilibrium pH value of 5.4 and an organic-to-aqueous phase ratio of 2/3. The loaded ionic liquid was quantitatively stripped in 2.0 mol·L−1 H2SO4 solution, which yielded high-purity CoSO4·xH2O crystals after evaporation of the stripped liquor. Subsequently, ∼99 % nickel was recovered as nickel carbonate [NiCO3·2Ni(OH)2] from the Co-depleted raffinate by the precipitation performed at Ni2+:CO32− ratio of 1:2.5, pH value of 10.8, and temperature of 50 °C. Finally, a process flow with mass and energy balances yielding a high recovery rate of all metals in the exhausted cathode powder of spent LiBs was proposed.

Direct Recycling of End-of-Life Li-Ion Cathode Materials through Redox Chemistry Mediators

Recycled lithium-ion (Li-Ion) battery materials are pivotal for the sustainability of the renewable energy industry. Widespread consumer and municipal adoption of electric vehicles (EVs) directly correlates to the increased demand for Li-Ion batteries. Increasing Li-Ion battery production to meet the demand presents two challenges: end-of-life (EoL) Li-Ion management through recycling and mineral depletion. Li-Ion batteries are manufactured with hazardous and volatile materials, hence, cannot be sent to landfills. Therefore, recycling is vital in preserving the environment and securing resources. The current research uses wet chemical separation of spent Li-Ion battery electrode materials. The method used in direct recycling of the delithiated Li-Ion cathode materials through redox chemistry mediators employs reduction and oxidation chemistry. Quinone compounds shuttles charges between lithium metal or lithium salt and delithiated cathode materials. This redox reaction occurs at low temperature to restore lithium content in the spent Li-ion battery electrode materials. The process recovers the lithium content in the cathode materials without negatively affecting the structure. The half-cell electrochemical performance is comparable to pristine material. Hence, redox chemistry relithiation for direct recycling is promising. Figure 1

Biohydrometallurgy for Cobalt Recovery from Spent Li-ion Batteries using Acidophilic Bacteria Isolated from Acid Mine Drainage

Biohydrometallurgy for Cobalt Recovery from Spent Li-ion Batteries using Acidophilic Bacteria Isolated from Acid Mine Drainage

Synthesis of Graphene Quantum Dots by a Simple Hydrothermal Route Using Graphite Recycled from Spent Li-Ion Batteries

Graphene quantum dots (GQDs) are nanosized systems that combine beneficial properties typical of graphenic materials (such as chemical stability, biocompatibility and ease of preparation from low-cost precursors) with remarkable photoluminescent features. GQDs are well-known for their low cytotoxicity and for being promising candidates in applications, such as bioimaging, optoelectronics, electrochemical energy storage, sensing and catalysis, among others. This work describes a simple and low-cost synthesis of GQDs, starting from an alcoholic aqueous suspension of graphene oxide (GO) and using a hydrothermal route. GO was prepared using graphite recycled from spent Li-ion batteries, via a modified Hummers method. The GO suspension was submitted to hydrothermal treatments at different temperatures using a homemade hydrothermal reactor that allows the control of the heating program and the assessment of the internal pressure generated in the reaction. The synthesized GQDs exhibited bright blue/green luminescence under UV light; showing the success of the chosen route and opening the way for future applications of these materials in the field of optoelectronic devices.

An emission-free controlled potassium pyrosulfate roasting-assisted leaching process for selective lithium recycling from spent Li-ion batteries

Recycling critical metals from spent Li-ion batteries (LIBs) is important for the overall sustainability of future batteries. This study reports an improved sulfation roasting technology to efficiently recycle Li and Co from spent LiCoO2 LIBs using potassium pyrosulfate as sulfurizing reagent. By sulfation roasting, LiCoO2 was converted into water-soluble lithium potassium sulfate and water-insoluble cobalt oxide. Under optimal conditions, 98.51% Li was leached in water, with a selectivity of 99.86%. More importantly, sulfur can be recirculated thoroughly, and the sulfur atomic efficiency can be significantly enhanced by controlling the amount of potassium pyrosulfate. Li ions from the water leaching process were recovered by chemical precipitation. Furthermore, application of this technology to other spent LIBs, such as LiMn2O4 and LiNi0.5Co0.2Mn0.3O2, verified its effectiveness for selective recovery Li. These findings can provide some inspiration for high efficiency and environmentally friendly recovery metal from spent LIBs.

Research progress on recovering the components of spent Li-ion batteries

Research progress on recovering the components of spent Li-ion batteries

Synergistic effect of Na and Al co-doping on the electrochemical properties of Li[Ni0.8Mn0.1Co0.1]O2 cathode materials for Li-ion batteries

In the typical hydrometallurgy-based recycling process of spent Li-ion batteries (LIBs), excessive amounts of Na ions are inevitably incorporated in leachate through a discharging process with salt solutions and a purification step for impurity removal. In this study, a facile Al3+ doping strategy is realized ranging from impurity level to usual doping levels for improving the LIB performance of Na-incorporated Li[Ni0.8Co0.1Mn0.1]O2 (N-NCM). We synthesize Na-incorporated hydroxide precursor via a coprecipitation reaction using a metal solution containing excess amounts of Na (12.6 mol%), simulating the resynthesis of NCM from purified leachate. The Na and Al co-doped NCM811 (NA-NCM) cathode materials are successfully synthesized by subsequent solid-state reactions with various concentrations of Al. The physicochemical and electrochemical properties of NA-NCM are systematically investigated, with N-NCM as a control sample. Notably, the trace amount of Al (0.05 mol%)-doped cathode material reveals the highest cyclability of 93.9% after 80 cycles at 1 C and more than six times higher discharge capacity (115 mAh g−1) at 20 C than N-NCM. Overall, the small amount of Al doping (0.05 mol%) makes the host structures stable and more favorable for Li+ diffusion, whereas the excessive Al (4 mol%) doping lead to the sluggish kinetics on rate capability due to thick A2O3 film layers formed on the particle surface. This work suggests the rational design for upgrading the resynthesized Ni-rich NCM cathode materials for the sustainable recycling of spent LIBs.

Recycling the waste LiMn2O4 of spent Li-ion batteries by pH gradient in neutral water electrolyser

The rapid development of electric vehicles powered by Li-ion batteries poses a challenge for the supply of raw materials, and will also generate significant battery waste. Recycling the spent Li-ion batteries not only mitigates the pressure on resource supply but also reduces environmental pollution. Herein, we present a comprehensive study on using pH gradient generated in neutral water electrolyser for recycling waste LiMn2O4 cathodes without addition of external acid, base or chemical reductant. Li+ and Mn2+ are leached from LiMn2O4 at low pH in the anode chamber, and manganese oxide is precipitated at high pH in the cathode chamber. H2 and O2 are also valuable byproducts of the process. Li+ can be recovered in the form of Li2CO3. Finally, the LiMn2O4 is re-synthesized, closing the loop. The exact roles of multiple variables on the leaching of LiMn2O4 as well as the associated phase evolution are carefully examined. In addition, γ-MnO2 is deposited on the anode during the process, and it is characterized to be a stable and relatively effective catalyst for oxygen evolution reaction in acid. The process demonstrated represents a promising approach for recovering waste LiMn2O4 of waste Li-ion batteries in an environmentally friendly way.

Recovery of Cobalt from Lithium-Ion Batteries Using Fluidised Cathode Molten Salt Electrolysis

Within the next 30 years, the number of vehicles powered by electricity is predicted to rise to 1 billion representing an exponential increase from 7.9 million used in 2019 [1]. These electrified vehicles will rely on lithium-ion rechargeable batteries with projections augmented by the impending ban on new petrol and diesel car sales. Despite these batteries offering a green, carbon-free alternative they remain overshadowed by the sustainable use of raw materials. Thus, the future need to recycle enormous quantities of Li-ion batteries arises because of the projected increase in the electrified fleet of vehicles required to decarbonise the transport sector. Cobalt is an essential element in several Li-ion battery cathode chemistries (e.g. NMC, NCA and LCO). In this study, we present an electrochemical reduction process of LiCoO2 to Co using a molten salt fluidised cathode technique at 450 oC [2]. Using thermodynamic calculations, a predominance diagram was constructed in Figure 1 to aid in understanding the reduction pathway. Cyclic voltammograms indicate two 2-electron transfer steps, the first where Co3O4 is reduced to CoO at −0.55 V vs Ag/Ag+ followed by the second reduction step of CoO to Co at −2.4 V vs. Ag/Ag+. The reduction potential of Co was used to determine the input parameters in the current versus time profiles. The Faradaic current efficiencies for both the commercially obtained LiCoO2 and spent Li-ion battery yield values greater than 70%. Thus, the fluidised cathode technique could prove to be an energy-efficient and high-throughput route for the recovery of cobalt, in this work, as well as different materials found in other batteries. Gielen, R. Gorini, N. Wagner, R. Leme and G. Prakash. International Renewable Energy Agency (IRENA), Global Renewables Outlook: Energy Transformation 2050, Abu Dhabi, Edition: 2020.M. Mirza, R. Abdulaziz, W.C. Maskell, C. Tan, P.R. Shearing, D.J.L. Brett, Recovery of cobalt from lithium-ion batteries using fluidised cathode molten salt electrolysis, Electrochim. Acta. 391 (2021) 138846. Figure 1

Binary Solvent System for Extraction of Cathode Material From Spent Li-ion Batteries

An effective method of water and carbon tetrachloride (CCl4) system has been studied to recover metals ions from spent Li-ion battery cathode materials. Leaching of HCl and HCl + H2O2 has been applied individually to dissolve the collected cathode materials. Metal ions dissolved in HCl and HCl + H2O2 has been treated separately with a solution of hexadecyl amine in CCl4. The formation of metal ions-hexadecyl amine complex has been confirmed from UV-visible spectroscopy. Recovery of metals from the produced complex has been carried out via filtration and calcination. The calcined materials has been characterized using Fourier transform infrared spectroscopy (FT-IR),field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) andpowder x-ray diffraction (XRD). Dhaka Univ. J. Sci. 69(3): 225-229, 2022 (June)

New method for selective recovery of manganese from NCM-based cathode material of spent Li-ion batteries

ABSTRACT This study provides a new leaching method for selective recovery of manganese from the spent NCM-based cathode active material of lithium-ion secondary batteries (LIBs). The recovery method involves the use of aqueous Mn(II) phase spontaneously generated in sulfate media as a reducing agent, in which Ni(III) and Co(III) are reduced to soluble species while Mn(II) precipitates as Mn(IV) oxides simultaneously. To optimize the process, the effects of time, temperature, and acid concentration on the leaching behavior were investigated. As a result, two-step successive leaching at an optimal condition was proposed, by which the dissolution efficiency of Co and Ni reached up to 99% and ~100%, respectively while Mn leaching was restricted to 15.5%. The leaching residue mainly consisted of manganese oxide (MnO2), containing Mn ~40%. The amount of Mn in the residue increased to ~70% by calcinating at 650 °C, which converted its phase into Mn2O3 and Mn3O4. Therefore, our two-step leaching technique will lead to the recovery of nearly all the contents of Li, Co, and Ni in addition to ~70% purity Mn as supplemental benefit from spent LIB materials without using any oxidants or reductants.