Electrochemical Speciation Control of LCO-Derived NADES Leachate: Cyclic Voltammetry, Chronopotentiometry, Cobalt Speciation and Screening LCA Data

This dataset supports a study on chemical-reductant-free electrochemical speciation control for cobalt recovery from lithium cobalt oxide (LCO)-derived natural deep eutectic solvent (NADES) leachate. The study tested whether galvanostatic electroreduction can convert dissolved Co(III)-rich species into more recoverable Co(II)-rich species without adding an external chemical reductant, and whether the added electrochemical burden is justified when assessed per unit of precipitable cobalt.
The dataset includes time-resolved cyclic voltammetry (CV), chronopotentiometry/galvanostatic treatment data, UV-vis/ICP-OES cobalt speciation tables, and a screening life-cycle/economic assessment workbook. The CV files provide time, potential, current and working-electrode potential data for evaluating electrochemical accessibility. The CP files record potential/current responses over 2,400 s treatment runs, enabling calculation of voltage behaviour, plateau stability, charge input and energy demand. The speciation tables report Co(III) and Co(II) concentrations before and after treatment across current and catholyte-volume conditions, including replicate measurements and reduction efficiencies.
The data show that LCO-derived NADES leachate is electrochemically active and that galvanostatic treatment shifts cobalt speciation from Co(III) toward Co(II). Fluorine-minimization pretreatment reduced total fluorine from 1.60 to 0.15 wt% and soluble fluoride from 151.3 to 5.76 mg L-1 before leaching. NADES leaching dissolved 94.7% of the feed mass and produced leachate containing about 15.32 g L-1 Co. Electrochemical treatment achieved approximately 39.56-95.04% Co(III)-to-Co(II) conversion, while total dissolved cobalt recovery remained high at 99.60 +/- 1.53%, indicating oxidation-state redistribution rather than cobalt loss. Conversion increased with current but decreased with catholyte volume, supporting normalized current dose, I/V, as a useful scale-up descriptor.
The LCA workbook is foreground screening assessment. Although electroreduction-assisted recovery has a higher per-batch climate burden than direct precipitation, it produces more precipitable cobalt. Normalized to cobalt output, electroreduction lowered climate impact intensity from about 48.0 to 27.1 kg CO2-eq kg-1 Co at 80% NADES recovery and from about 28.9 to 18.1 kg CO2-eq kg-1 Co at 90% recovery. The dataset can be used to replot electrochemical traces, calculate charge and energy metrics, reproduce cobalt speciation mass balances, compare current/volume effects, and test foreground LCA assumptions for NADES-assisted cobalt recovery.