A novel green deep eutectic solvent for one-step selective separation of valuable metals from spent lithium batteries: Bifunctional effect and mechanism.

This study used a novel green bifunctional deep eutectic solvent (DES) containing ethylene glycol (EG) and tartaric acid (TA) for the efficient and selective recovery of cathode active materials (LiCoO2 and Li3.2Ni2.4Co1.0Mn1.4O8.3) used in lithium-ion batteries through one-step in-situ separation of Li and Co/Ni/Mn. The effects of leaching parameters on the recovery of Li and Co (ηLi and ηCo) from LiCoO2 are discussed, and the optimal reaction conditions are verified, for the first time, using a response surface method. The results demonstrate that under optimal conditions (120 °C, 12 h, EG to TA mole ratio (MEG:TA) of 5:1, and solid to liquid ratio (RS/L) of 20 g/L), the ηLi from LiCoO2 reached 98.34%, and Co was formed as a purple precipitate of cobalt tartrate (CoC4H4O6), which was transformed into a black powder of Co3O4 after calcination. Notably, the ηLi for DES 5 EG:1 TA was maintained at 80% after five cycles, indicating good cyclic stability. When the as-prepared DES was used to leach the spent active material Li3.2Ni2.4Co1.0Mn1.4O8.3, the in-situ selective separation of Li (ηLi = 98.86%) from other valuable elements such as Ni, Mn, and Co, was achieved, indicating the good selective leaching capacity and practical application potential of the DES.

Photocatalytic and Cathode Active Abilities of Ni-Substituted α-FeOOH Nanoparticles.

The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (NixFe1-xOOH NPs) with a range of 'x' values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); 57Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer-Emmett-Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of NixFe1-xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)2 in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10-3 min-1. The 57Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s-1 and a hyperfine magnetic distribution (Bhf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10-10 to 5.30 × 10-12 (Ω cm)-1 with 'x' increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g-1, attributed to its largest specific surface area of 174.0 m2 g-1. In conclusion, NixFe1-xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries.

Inverse Vulcanization of a Natural Monoene with Sulfur as Sustainable Electrochemically Active Materials for Lithium-Sulfur Batteries.

A novel soluble copolymer poly(S-MVT) was synthesized using a relatively quick one-pot solvent-free method, inverse vulcanization. Both of the two raw materials are sustainable, i.e., elemental sulfur is a by-product of the petroleum industry and 4-Methyl-5-vinylthiazole (MVT) is a natural monoene compound. The microstructure of poly(S-MVT) was characterized by FT-IR, 1H NMR, XPS spectroscopy, XRD, DSC SEM, and TEM. Test results indicated that the copolymers possess protonated thiazole nitrogen atoms, meso/macroporous structure, and solubility in tetrahydrofuran and chloroform. Moreover, the improved electronic properties of poly(S-MVT) relative to elemental sulfur have also been investigated by density functional theory (DFT) calculations. The copolymers are utilized successfully as the cathode active material in Li-S batteries. Upon employment, the copolymer with 15% MVT content provided good cycling stability at a capacity of ∼514 mA h g-1 (based on the mass of copolymer) and high Coulombic efficiencies (∼100%) over 100 cycles, as well as great rate performance.

Leaching of NMC industrial black mass in the presence of LFP.

This study focuses on the effect of an emerging source of waste, lithium iron phosphate (LFP) cathode materials, on the hydrometallurgical recycling of the currently dominant industrial battery waste that is rich in transition metals (Ni, Co, Mn, and Li). The effects of the dosage of LFP, initial acidity, and timing of LFP reductant addition were investigated in sulfuric acid (H2SO4) leaching (t = 3 h, T = 60 °C, ω = 300 rpm). The results showed that addition of LFP increased both transition metal extraction and acid consumption. Further, the redox potential was lowered due to the increased presence of Fe2+. An initial acidity of 2.0 mol/L H2SO4 with acid consumption of 1.3 kg H2SO4/kg black mass provided optimal conditions for achieving a high leaching yield (Co = 100%, Ni = 87.6%, Mn = 91.1%, Li = 100%) and creating process solutions (Co 8.8 g/L, Ni 13.8 g/L, Li 6.7 g/L, Mn 7.6 g/L, P 12.1 g/L) favorable for subsequent hydrometallurgical processing. Additionally, the overall efficiency of H2O2 decreased due to its decomposition by high concentrations of Fe2+ and Mn2+ when H2O2 was added after t = 2 h, leading to only a minor increase in final battery metals extraction levels.

Coating Robust Layers on Ni-Rich Cathode Active Materials while Suppressing Cation Mixing for All-Solid-State Lithium-Ion Batteries.

This study focused on addressing the challenges associated with the incompatibility between sulfide solid electrolytes and Ni-rich cathode active materials (CAMs) in all-solid-state lithium-ion batteries. To resolve these issues, protective layers have been explored for Ni-rich materials. Lithium lanthanum titanate (LLTO), a perovskite-type material, is recognized for its excellent chemical stability and ionic conductivity, which render it a potential protective layer in CAMs. However, traditional methods of achieving the perovskite structure involve temperatures exceeding 700 °C, resulting in challenges such as LLTO agglomeration, secondary phase formation between LLTO and CAM, and cation mixing within the CAM. In this study, a rapid technique known as flash-light sintering (FLS) was employed to fabricate a uniform and pure perovskite protective layer without inducing cation mixing within the CAM. The LLTO-coated LiNi0.8Co0.1Mn0.1O2 (NCM811) with FLS treatment demonstrated minimal cation mixing and formed a fully covered dense layer. This resulted in a high initial capacity and effectively addressed the incompatibility issues between the sulfide electrolytes and CAM. The rapid FLS method not only streamlines the fabrication of LLTO-coated NCM811 but also provides opportunities for its broader application to materials that were previously deemed impractical because of high sintering temperatures.

FeF3/(Acetylene Black and Multi-Walled Carbon Nanotube) Composite for Cathode Active Material of Thermal Battery through Formation of Conductive Network Channels.

Considerable research is being conducted on the use of FeF3 as a cathode replacement for FeS2 in thermal batteries. However, FeF3 alone is inefficient as a cathode active material because of its low electrical conductivity due to its wide bandgap (5.96 eV). Herein, acetylene black and multi-walled carbon nanotubes (MWCNTs) were combined with FeF3, and the ratio was optimized. When acetylene black and MWCNTs were added separately to FeF3, the electrical conductivity increased, but the mechanical strength decreased. When acetylene black and MWCNTs were both added to FeF3, the FeF3/M1AB4 sample (with 1 wt.% MWCNTs and 4% AB) afforded a discharge capacity of approximately 74% of the theoretical capacity (712 mAh/g) of FeF3. Considering the electrical conductivity and mechanical strength, this composition was confirmed to be the most suitable.

A process using a thermal reduction for producing the battery grade lithium hydroxide from wasted black powder generated by cathode active materials manufacturing.

Recent lithium consumption is doubled in a decade due to the Li-ion battery (LIB) demand for electric vehicles, the energy storage system, etc. The LIBs market capacity is expected to be in strong demand due to the political drive by many nations. Wasted black powders (WBP) are generated from the manufacturing of the cathode active material and spent LIBs. The recycling market capacity is also expected to expand rapidly. This study is to propose a thermal reduction technique for recovering Li selectively. The WBP, containing 7.4 % Li, 62.1 % Ni, 4.5 % Co, and 0.3 % Al, was reduced in a vertical tube furnace using a 10 % H2 gas as a reducing agent at 750 ºC for 1 h, and 94.3 % of Li was recovered from a water leaching, while other metal values, including Ni and Co remained in the residue. A leach solution was treated in a series of crystallisations, filtering, and washing. An intermediate product was produced and re-dissolved in hot water at 80 ºC for 0.5 h to minimise Li2CO3 content into a solution. A final solution was crystallised repeatedly to produce the final product. A 99.5 % of LiOH·H2O was characterised and passed the impurity specification by the manufacturer as a marketable product. The proposed process is relatively simple to utilise to scale up for bulk production, and it can also be contributed to the battery recycling industry as the spent LIBs are expected to overabundance within the near future. A brief cost evaluation confirms the process feasibility, particularly, for the company that produces cathode active material (CAM) and generates WBP in their own supply chain.

Electrochemical Performance of Layer-Structured Ni0.8Co0.1Mn0.1O2 Cathode Active Materials Synthesized by Carbonate Co-Precipitation.

The layered Ni-rich NiCoMn (NCM)-based cathode active material Li[NixCo(1-x)/2Mn(1-x)/2]O2 (x ≥ 0.6) has the advantages of high energy density and price competitiveness over an LiCoO2-based material. Additionally, NCM is beneficial in terms of its increasing reversible discharge capacity with the increase in Ni content; however, stable electrochemical performance has not been readily achieved because of the cation mixing that occurs during its synthesis. In this study, various layer-structured Li1.0[Ni0.8Co0.1Mn0.1]O2 materials were synthesized, and their electrochemical performances were investigated. A NiCoMnCO3 precursor, prepared using carbonate co-precipitation with Li2CO3 as the lithium source and having a sintering temperature of 850 °C, sintering time of 25 h, and metal to Li molar ratio of 1.00-1.05 were found to be the optimal parameters/conditions for the preparation of Li1.0[Ni0.8Co0.1Mn0.1]O2. The material exhibited a discharge capacity of 160 mAhg-1 and capacity recovery rate of 95.56% (from a 5.0-0.1 C-rate).

Ab initiodescription of disorder effects in layered cathode active materials by the coherent potential approximation.

Disorder effects in alloys are usually modeled by averaging various supercell calculations considering different positions of the alloy atoms. This approach, however, is only possible as long as the portion of the individual components of the alloy is sufficiently large. Herein, we present anab initiostudy considering the lithium insertion material Li1-x[Ni0.33Co0.33Mn0.33]O2as model system to demonstrate the power of the coherent potential approximation within the Korringa-Kohn-Rostoker Green's function method. This approach enables the description of disorder effects within alloy systems of any composition. It is applied in this study to describe the (de-)intercalation of arbitrary amounts of lithium from the cathode active material. Moreover, we highlight that using either fully optimized structures or experimental lattice parameters and atomic positions both lead to comparable results. Our findings suggest that this approach is also suitable for modeling the electronic structure of state-of-the-art materials such as high-nickel alloys.

Application of µ-Nitrido- and µ-Carbido-Bridged Iron Phthalocyanine Dimers as Cathode-Active Materials for Rechargeable Batteries.

µ-Nitrido- and µ-carbido-bridged iron phthalocyanine dimers, when used as cathode-active materials for rechargeable lithium batteries, showed four stable redox waves in cyclic voltammetry studies in solution and a stable discharge capacity of approximately 60 mAh g-1 after 200 cycles. These results indicate that µ-heteroatom-bridged iron phthalocyanine dimers are good platforms for designing novel phthalocyanine-based electrode-active materials.

A Rapid and Facile Approach for the Recycling of High-Performance LiNi1-x-y Cox Mny O2 Active Materials.

The demand for lithium-ion batteries has risen dramatically over the years. Unfortunately, many of the essential component materials, such as cobalt and lithium, are both costly and of limited abundance. For this reason, the recycling of lithium-ion battery electrodes is crucial to ensuring the availability of such resources and protecting the environment. Herein, a simple and scalable recycling process was developed for the prototypical cathode active material Li1.02 (Ni0.8 Co0.1 Mn0.1 )0.98 O2 (NCM-811). By a combination of thermal decomposition and dissolution steps, spent NCM could be converted into Li2 CO3 and a transition metal oxalate blend, which served as precursors for new NCM. Importantly, it was also possible to individually separate each transition metal during the recycling process, thereby extending the utility of this method to a wide variety of NCM compositions. Each intermediate in the process was investigated by scanning electron microscopy and X-ray diffraction. Additionally, the elemental composition of the recycled NCM-811 was confirmed using inductively coupled plasma optical emission spectroscopy and energy-dispersive X-ray spectroscopy. The electrochemical performance of the recycled NCM-811 exhibited up to 80 % of the initial capacity of pristine NCM-811. The method presented herein serves as an efficient and environmentally benign alternative to existing recycling methods for lithium-ion battery electrode materials.

Composition analysis of the cathode active material of spent Li-ion batteries leached in citric acid solution: A study to monitor and assist recycling processes.

Spent Li-ion batteries (LIBs) despite being produced with valuable metals from non-renewable natural resources are considered hazardous solid wastes because they contain metals and organic solvents pollutants for the environment. Due to this, it becomes necessary to know the chemical composition of these spent batteries to assist in the proper disposal and/or recycling process. This study aimed to provide quantitative data regarding the chemical composition of the cathode active material (CAM) of eight different spent LIBs used in cell phones and propose relationship with their energy capacity, year of manufacture and brand. CAM powder was leached using an environmentally friendly process with citric acid (2.0 mol L-1) and H2O2 (0.25 mol L-1), and the metals concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP OES). Co (43-67 wt%), Li (5.3-6.8 wt%), Mn (0.8-8.2 wt%), Ni (0.1-11.7 wt%) and Al (0.06-3.2 wt%) were present in higher concentrations, whereas Cr (0.0005-0.002 wt%), Cu (0.01-0.05 wt%), Mg (0.005-0.02 wt%), Ti (0.001-0.07 wt%), Ga (0.0009-0.03 wt%) and Zn (0.009-0.05 wt%) were present in lower concentrations. The result obtained showed a considerable variation between CAM elemental composition, which may be related to type of electrolyte, energy capacity and year of manufacture. Since this difference in chemical composition is not shown on product labels, this work using a green leaching process and a suitable analytical method may assist in the recycling processes and avoid the inappropriate disposal of the material.

The Role of Intragranular Nanopores in Capacity Fade of Nickel-Rich Layered Li(Ni1-x-yCoxMny)O2 Cathode Materials.

Ni-rich layered LiNi1-x-yCoxMnyO2 (NCM, x + y ≤ 0.2) is an intensively studied class of cathode active materials for lithium-ion batteries, offering the advantage of high specific capacities. However, their reactivity is also one of the major issues limiting the lifetime of the batteries. NCM degradation, in literature, is mostly explained both by disintegration of secondary particles (large anisotropic volume changes during lithiation/delithiation) and by formation of rock-salt like phases at the grain surfaces at high potential with related oxygen loss. Here, we report the presence of intragranular nanopores in Li1+x(Ni0.85Co0.1Mn0.05)1-xO2 (NCM851005) and track their morphological evolution from pristine to cycled material (200 and 500 cycles) using aberration-corrected scanning transmission electron microscopy (STEM), electron energy loss spectroscopy, energy dispersive X-ray spectroscopy, and time-of-flight secondary ion mass spectrometry. Pores are already found in the primary particles of pristine material. Any potential effect of TEM sample preparation on the formation of nanopores is ruled out by performing thickness series measurements on the lamellae produced by focused ion beam milling. The presence of nanopores in pristine NCM851005 is in sharp contrast to previously observed pore formation during electrochemical cycling or heating. The intragranular pores have a diameter in the range between 10 and 50 nm with a distinct morphology that changes during cycling operation. A rock-salt like region is observed at the pore boundaries even in pristine material, and these regions grow with prolonged cycling. It is suggested that the presence of nanopores strongly affects the degradation of high-Ni NCM, as the pore surfaces apparently increase (i) oxygen loss, (ii) formation of rock-salt regions, and (iii) strain-induced effects within the primary grains. High-resolution STEM demonstrates that nanopores are a source of intragranular cracking during cycling.

Recovery of valuable metals from cathodic active material of spent lithium ion batteries: Leaching and kinetic aspects.

This work is focussed on the processing of cathodic active material of spent lithium ion batteries (LIBs) to ensure resource recovery and minimize environmental degradation. The sulfuric acid leaching of metals was carried out for the recovery of all the valuable metals including nickel and manganese along with the frequently targeted metals like lithium and cobalt. The process parameters such as acid concentration, pulp density, time and temperature for the leaching of metals from the cathode powder containing 35.8% Co, 6.5% Li, 11.6% Mn and 10.06% Ni, were optimized. Results show the optimized leach recovery of 93.4% Li, 66.2% Co, 96.3% Ni and 50.2% Mn when the material was leached in 1M H2SO4 at 368 K and 50 g/L pulp density for 240 min. The need of a reductant for improved recovery of cobalt and manganese has been explained by the thermodynamic analysis (Eh-pH diagram) for these metals. Leaching of the valuable metals was found to follow the logarithmic rate law controlled by surface layer diffusion of the lixiviant reacting with the particles. The mode of leaching of the metals from the spent LIBs was further examined by chemical analysis of the samples at various stage of processing which was further corroborated by characterizing the untreated sample and the leach residues by XRD phase identification and the SEM-EDS studies.