Selective Electrochemical Recovery of Co, Ni, Mn from NMC Leachates using NADES-Dataset,2026
Description
Abstract / Summary: This dataset supports the study on electrochemical recovery of Co, Ni, and Mn from NMC 622 cathode leachates using natural deep eutectic solvents (NADES). The data includes raw and processed results from cyclic voltammetry (CV), chronopotentiometry (CP), UV–Vis spectroscopy, ICP-OES metal quantification, electrochemical impedance spectroscopy (EIS), and associated modeling outputs. Research Hypothesis: Transition metals in NMC leachates complexed with NADES are electrochemically addressable and can be selectively reduced under current-programmed galvanostatic conditions. By controlling applied current and catholyte volume, the reduction efficiency and Faradaic utilization of Co, Ni, and Mn can be maximized independently, providing a path to energy-efficient, selective metal recovery. Description of Data and Collection: Electrochemical Data: CV scans (10–100 mV s⁻¹) and CP voltage responses (50–100 mA) for varying catholyte volumes (15–30 mL) were recorded using a DHElecChem7000 workstation in divided H-cells. Metal Speciation: UV–Vis spectroscopy and ICP-OES quantified M²⁺/M³⁺ concentrations before and after electrochemical reduction. Faradaic efficiency calculations and residual metal concentrations were derived. EIS Data: Nyquist and Bode plots across 1 mHz–100 kHz, with plateau-resolved Rs, Rct, and Warburg parameters, describe interfacial and diffusion limitations. Model Outputs: Three-layer modeling data capturing volumetric charge density, metal-specific reduction kinetics, and Faradaic efficiency constraints, along with quadratic response-surface optimization results. Notable Findings: Co(III) reduction is optimized at 20 mL catholyte and 60 mA with 93.88% conversion; residual Co(III) = 77.37 mg L⁻¹. Ni(III) and Mn(III) conversions peak at 20 mL, 100 mA with 75.68% and 91.35%, respectively. Faradaic efficiency is maximized at intermediate currents, balancing electron utilization and metal recovery. EIS analysis indicates reduced Rct at higher currents, confirming enhanced electron transfer and interface activation. Multi-layer modeling demonstrates the critical interplay between current, catholyte volume, and metal-specific kinetics, enabling process design optimization. Interpretation and Use: Data can be used to validate NADES-based selective metal recovery, develop electrochemical process maps, and optimize multi-metal reduction strategies. Researchers can interpret CV and CP data to identify redox windows, use UV–Vis/ICP-OES data to quantify metal conversion, and EIS data to understand interfacial kinetics. Modeling outputs enable prediction of operating conditions for maximum conversion and energy efficiency. Data Format: CSV files for raw and processed electrochemical, spectroscopic, and modeling data. Recommendations for Reuse: Researchers may reproduce experiments for similar NMC-NADES systems or use datasets for modeling and optimization of selective electrochemical recovery processe
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Steps to reproduce
1. Research Design The study investigates selective electrochemical recovery of transition metals (Co, Ni, Mn) from NMC 622 cathode leachates using natural deep eutectic solvents (NADES). The hypothesis is that NADES can solubilize transition metals and enable controlled electrochemical reduction under current-programmed conditions. 2. Materials and Reagents Cathode Material: Spent LiNi₀.₆Mn₀.₂Co₀.₂O₂ (NMC 622) black mass. Solvents: Natural deep eutectic solvents (NADES) prepared using combinations of lactic acid, citric acid, ascorbic acid, and betaine. Electrolytes: NADES-based catholytes prepared in precise molar ratios. Reagents for Analysis: UV–Vis calibration standards, ICP-OES reference standards. 3. Instrumentation Electrochemical Workstation: DHElecChem7000 for cyclic voltammetry (CV) and chronopotentiometry (CP). UV–Vis Spectrophotometer: For metal concentration measurements before and after electrochemical experiments. ICP-OES: Quantitative metal analysis. Electrochemical Impedance Spectroscopy (EIS): Measurements using the same workstation with frequency sweep from 1 mHz to 100 kHz. 4. Experimental Protocols NADES Preparation: Mix acids and betaine in precise molar ratios at 50–60 °C until homogeneous. Store at ambient conditions; degas prior to electrochemical use. Leachate Dissolution: Dissolve NMC 622 black mass in NADES under controlled temperature. Measure initial metal concentrations using ICP-OES. Electrochemical Reduction: Load leachate into divided H-cells with NADES as catholyte. Apply programmed current using CP for predetermined times. CV scans performed at 10–100 mV/s to identify redox potentials. Monitor voltage and current responses continuously. Metal Quantification: After reduction, collect aliquots for UV–Vis and ICP-OES analysis. Determine residual metal concentrations and calculate conversion efficiencies. Impedance Analysis: Perform EIS at open-circuit potential and under applied current to analyze interfacial resistance and diffusion limitations. 5. Data Processing and Software Raw Data Export: CV, CP, and EIS data exported in CSV format from the workstation. Data Analysis: Faradaic efficiency and metal conversion calculated using Excel and Python scripts. Modeling performed using multi-layer kinetic simulations to predict optimal current and volume conditions. Graphs plotted in OriginPro and Excel for visualization. Documentation: Metadata includes catholyte composition, applied current, temperature, catholyte volume, and measurement parameters. 6. Reproducibility Notes Ensure NADES composition, leachate concentration, and current-programmed protocol are strictly followed. Metal quantification methods (ICP-OES, UV–Vis) require calibration with standards to ensure accuracy. EIS requires careful electrode preparation to avoid artifacts. The dataset contains all raw and processed measurements, allowing reproduction of Faradaic efficiency, metal conversion trends, and modeling validation.
Institutions
- Shanxi UniversityShanxi, Taiyuan