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

CO2 capture enhancement of different zeolites through the utilization of valuable cathode metals from spent lithium-ion batteries

Due to their exceptional properties, lithium-ion batteries are widely utilized in electronic devices and electric vehicles. However, their extensive use has highlighted the need for environmentally sustainable recycling methods. This study proposes a novel approach by using metals from spent lithium-ion batteries to modify CO2 capture abilities of different zeolite types, thereby contributing to the global progress towards achieving net zero emissions. The leach liquor was obtained by leaching metals from the batteries using a mixture of H2SO4 and H2O2. The study investigated the effect of ion concentrations on CO2 adsorption, including both breakthrough and full capacity. While no significant improvement in CO2 capture was observed for most zeolites, zeolite A showed enhanced breakthrough capacity after ion exchange. The breakthrough curve for zeolite A, with data points below 10 % breakthrough, was effectively modelled using the Bohart-Adams model. The results demonstrated the potential of zeolites, especially zeolite LTA, in both recycling metals from lithium-ion batteries and enhancing CO2 adsorption capacity.

Improved recovery of lithium from spent lithium-ion batteries by reduction roasting and NaHCO3 leaching

Lithium supply risk is increasing and driving rapid progress in lithium recovery schemes from spent lithium-ion batteries (LIBs). In this study, a facile recycling process consisting mainly of reduction roasting and NaHCO3 leaching was adopted to improve lithium recovery. The Li of spent LiNixCoyMn1-x-yO2 powder were converted to Li2CO3 and LiAlO2 with the reduction effect of C and residual Al in the roasting process. NaHCO3 leaching was utilized to selectively dissolve lithium from Li2CO3 and water-insoluble LiAlO2. The activation energy of NaHCO3 leaching was 9.31 kJ∙mol-1 and the leaching of lithium was a diffusion control reaction. More than 95.19 % lithium was leached and recovered as a Li2CO3 product with a purity of 99.80 %. Thus, this approach provides a green path to selective recovery of lithium with good economics.

Towards a low-emission resource circulation of valuable metals from municipal solid waste incineration fly ash

The incineration fly ash (IFA) resulting from municipal solid waste combustion is laden with heavy metals, necessitating proper treatment not only for environmental management but also to reclaim the metal values. The surge in non-traditional metals like cobalt as emerging contaminant within IFA samples further attracts to address this issue. In response, the hydrometallurgical recycling of a cobalt-bearing IFA has been studied. Thereby, approximately 98 % zinc and 96 % cobalt were leached using a 1.0 mol/L H2SO4 solution at 90 °C and 1 h of leaching time. In-depth analysis of the leaching process unveiled metals' dissolution primarily via the ion-exclusion mechanism, as evidenced by lower diffusion coefficients (between 10-9 and 10-11 m2/s) and activation energies (9.6-14.9 kJ/mol). Above 99 % separation of zinc from the cobalt-bearing leach liquor was achieved by extraction with 1.0 mol/L D2EHPA at an equilibrium pH below 3.0, followed by stripping with a 2.0 mol/L H2SO4 solution. Cobalt, remained in the raffinate was efficiently precipitated by adding a 20 % excess dosage of oxalic acid to the stoichiometric ratio of C2O42-:Co2+, resulting in only 5 mg/L cobalt left in the solution when precipitation occurred at a pH of 2.8. Additionally, the conversion of CoC2O4 to high-purity Co3O4 was conducted through heat-treatment at 600 °C. The resulting Co3O4 was mixed with Li2CO3 at a Li/Co molar ratio of 1.1, yielding a LiCoO2 precursor that exhibited good electrochemical properties with a capacity of 128 mAh/g, thus affirming the high quality of the recycled cobalt. A comprehensive life-cycle assessment of the recycling process revealed that cobalt precipitation alone contributes approximately 50 % of the total global warming potential (GWP = 4.2624 kg CO2-eq). Notably, this value is remarkably lower than the GWP reported for primary cobalt production, highlighting the environmentally-friendly approach of this recycling endeavor.

Review of lithium-ion batteries' supply-chain in Europe: Material flow analysis and environmental assessment

European legislation stated that electric vehicles' sale must increase to 35% of circulating vehicles by 2030, and concern is associated to the batteries' supply chain. This review aims at analysing the impacts (about material flows and CO2 eq emissions) of Lithium-Ion Batteries' (LIBs) recycling at full-scale in Europe in 2030 on the European LIBs' supply-chain. Literature review provided the recycling technologies' (e.g., pyro- and hydrometallurgy) efficiencies, and an inventory of existing LIBs' production and recycling plants in Europe. European production plants exhibit production capacity adequate for the expected 2030 needs. The key critical issues associated to recycling regard pre-treatments and the high costs and environmental impacts of metallurgical processes. Then, according to different LIBs' composition and market shares in 2020, and assuming a 10-year battery lifetime, the Material Flow Analysis (MFA) of the metals embodied in End of Life (EoL) LIBs forecasted in Europe in 2030 was modelled, and the related CO2 eq emissions calculated. In 2030 the European LIBs' recycling structure is expected to receive 664 t of Al, 530 t of Co, 1308 t of Cu, 219 t of Fe, 175 t of Li, 287 t of Mn and 486 t of Ni. Of these, 99% Al, 86% Co, 96% Cu, 88% Mn and 98% Ni will be potentially recovered by pyrometallurgy, and 71% Al, 92% Co, 92% Fe, 96% Li, 88 % Mn and 90% Ni by hydrometallurgy. However, even if the recycling efficiencies of the technologies applied at full-scale are high, the treatment capacity of European recycling plants could supply as recycled metals only 2%-wt of the materials required for European LIBs' production in 2030 (specifically 278 t of Al, 468 t of Co, 531 t of Cu, 114 t of Fe, 95 t of Li, 250 t of Mn and 428 t of Ni). Nevertheless, including recycled metals in the production of new LIBs could cut up 28% of CO2 eq emissions, compared to the use of virgin raw materials, and support the European batteries' value chain.

Recent progress on hard carbon and other anode materials for sodium-ion batteries

The incorporation of intermittent renewable energy sources into a consistently controlled power transmission system hinges on advancements in energy storage technologies. Sodium ion batteries (SIBs) are emerging as a primary and viable alternative material due to their electrochemical activity, presenting a potential replacement for the next generation of lithium-ion battery (LIB) energy storage materials. However, this transition may necessitate significant alterations in the anode material, given the incompatibility of the current anode with sodium ions and the electrolyte. This review provides a comprehensive summary of various anode materials employed in SIBs, categorized according to their storage mechanisms. Additionally, it explores the growing focus on utilizing hard carbon as an anode material, driven by factors such as its relatively high specific capacity compared to graphite, cost-effective production, and eco-friendly properties as it can be derived from biomass. The review further addresses recent progress in hard carbon, detailing production methods, modifications, challenges, limitations in integrating hard carbon into the anode of SIBs, and suggests potential directions for future research.

High-performance expanded graphite regenerated from spent lithium-ion batteries by integrated oxidation and purification method

Currently, the recycling of spent lithium-ion batteries (LIBs) has mainly been focused on the extraction of precious metals, such as lithium, cobalt and nickel from cathodes, while the waste graphite anode has been overlooked due to its low-cost production and abundant resources reserve. However, there are enormous potential value and pollution risk in the view of graphite recycling. Thus, we propose an original method to prepare expanded graphite (EG) as new anode material generated from waste graphite in LIBs which integrates the oxidation and purification in one-step. By regulating the oxidizability of potassium hypermanganate in the sulfur-phosphorus mixed acid system, the expansion of graphite and removal of impurities are realized simultaneously and thoroughly. As anticipated, the shortening of preparation process and purification procedure can also reduce the generation of polluting substances and production cost. It displays excellent electrochemical performance (reversible capacity of 435.8 mAh·g-1 at 0.1C and long-term cycling property of 370 mAh·g-1 at 1C after 1000 cycles), which is even higher than that of pristine commercial graphite. This delicate strategy of high-performance expanded graphite recycling achieves the integration of purification and value-added processes, providing the instructive guide to regenerate industrial-grade anode materials for the increasing LIBs demand in the future.

Prospects of recycling from end-of-life of Li-ion batteries on alleviating materials demand-supply gap in new electric vehicles in Asia

The acceptance of battery electric vehicles (BEVs) is continuously increasing to mitigate CO2 emissions, resulting in an increase in the future material demand for LIBs. Therefore, the proper handling of End-of-life (EOL) BEV batteries requires careful attention to mitigate the supply chain issues for future LIBs materials, especially in Asia. A system dynamics model assessment was performed to evaluate the EOL of LIBs by considering the dynamic lifespan, recovery rate, and economic value under three growth rate scenarios in Asia from 2022 to 2030, depending on the battery chemistry over time. We find that comparing three different scenarios to materials demand, the result showed that materials demand for LIBs is greater in higher scenarios as compared with lower and reference scenarios. Moreover, in the low scenario, the nickel demand and recovery from end-of-life LIBs BEVs will achieve 244.0 and 43.28 kt in 2030. Based on the dynamic economic evaluation, an overall, higher potential economic value of all materials would achieve around 1471 million USD in 2030 in the low scenario. This study manifested that recycling LIBs materials has enormous economic potential and would be a step towards economic sustainability, especially in Asia in the near future.

Degradation of tetrabromobisphenol A (TBBA) with calcium hydroxide: a thermo-kinetic analysis

Thermal treatment of bromine-contaminated polymers (i.e., as in e-waste) with metal oxides is currently deployed as a mainstream strategy in recycling and resources recovery from these objects. The underlying aim is to capture the bromine content and to produce pure bromine-free hydrocarbons. Bromine originates from the added brominated flame retardants (BFRs) to the polymeric fractions in printed circuits boards, where tetrabromobisphenol A (TBBA) is the most utilized BFR. Among notable deployed metal oxides is calcium hydroxide, i.e., Ca(OH)₂ that often displays high debromination capacity. Comprehending thermo-kinetic parameters that account for the BFRs:Ca(OH)₂ interaction is instrumental to optimize the operation at an industrial scale. Herein, we report comprehensive kinetics and thermodynamics studies into the pyrolytic and oxidative decomposition of a TBBA:Ca(OH)₂ mixture at four different heating rates, 5, 10, 15, and 20 °C min^-1, carried out using a thermogravimetric analyser. Fourier Transform Infrared Spectroscopy (FTIR) and a carbon, hydrogen, nitrogen, and sulphur (CHNS) elemental analyser established the vibrations of the molecules and carbon content of the sample. From the thermogravimetric analyser (TGA) data, the kinetic and thermodynamic parameters were evaluated using iso-conversional methods (KAS, FWO, and Starink), which were further validated by the Coats-Redfern method. The computed activation energies for the pyrolytic decomposition of pure TBBA and its mixture with Ca(OH)₂ reside in the narrow ranges of 111.7-112.1 kJ mol^-1 and 62.8-63.4 kJ mol^-1, respectively (considering the various models). Obtained negative ΔS values suggest the formation of stable products. The synergic effects of the blend exhibited positive values in the low-temperature ranges (200-300 °C) due to the emission of HBr from TBBA and the solid-liquid bromination process occurring between TBBA and Ca(OH)₂. From a practical point of view, data provided herein are useful in efforts that aim to fine-tune operational conditions encountered in real recycling scenarios, i.e., in co-pyrolysis of e-waste with Ca(OH)₂ in rotary kilns.