Acid leaching of LiCoO2 enhanced by reducing agent. Model formulation and validation

Recovery of metal ion resources from waste lithium batteries by in situ electro-leaching coupled with electrochemically switched ion exchange

A new green pathway of in situ electro-leaching coupled with electrochemically switched ion exchange (EL-ESIX) technology was developed for the separation and recovery of valuable metal ions from waste lithium batteries. By using the in situ electro-leaching, the leaching rates of Li+ and Co2+ from the prepared LiCoO2 film electrodes reached 100 % and 93.30 %, respectively, under the combined effect of the acidic microenvironment formed by the anodic electrolytic water and electrostatic repulsion. Subsequently, the Li+ in the electrolyte was further extracted by an electrochemically switched ion exchange (ESIX) process using LiMn2O4 as the film electrode, and Li+ was further enriched in the eluate by a cyclic adsorption and desorption process. The results indicate that the in situ electro-leaching has significant advantages over powder leaching, and for the recycling of waste lithium batteries, the final lithium recovery rate reached 94.51 % by using this in situ EL-ESIX technology.

Green and efficient recycling method for spent Ni-Co-Mn lithium batteries utilizing multifunctional deep eutectic solvents

Given the growing volume of discarded lithium-ion batteries (LIBs), the extraction and recovery of valuable metals through environmentally-friendly solvent processes have become crucial, but they remain challenging tasks. Deep eutectic solvent (DES), an innovative and green solvents, have demonstrated significant promise in the extraction of valued metal elements from spent LIBs. This work employed a multifunctional DES based on natural molecules dimethyl-beta-propiothetin (DMPT) and ethylene glycol (EG) for the efficient leaching of transition metal ions. Under the reduction effect of EG and the action of carboxyl groups and chloride ions in DMPT, the leaching rate of Li, Ni, Co, and Mn can reach 99.59%, 99.28%, 99.04%, and 99.45%, respectively. Furthermore, DFT calculations were employed to explore the microstructure of DES and its interactions with metal ions. The main active site in the DES molecule is near the chloride ion, and DES binds most strongly to Mn, followed by Co, and weakest to Ni. This work avoids the use of volatile acids and demonstrates great potential in extracting valuable metals, providing a sustainable and environment-friendly alternative for the efficient recycling of waste LIBs.

Extraction of precious metals from used lithium-ion batteries by a natural deep eutectic solvent with synergistic effects

As the demand for lithium-ion batteries rises, the growing quantity of waste produced from lithium-ion battery electrode materials becomes an issue of concern. We propose a novel approach for effectively extracting precious metals from cathode materials that address the problem of secondary pollution and high energy consumption that arise from the conventional wet recovery process. The method employs a natural deep eutectic solvent (NDES) composed of betaine hydrochloride (BeCl) and citric acid (CA). The leaching rates of manganese (Mn), nickel (Ni), lithium (Li), and cobalt (Co) in cathode materials may reach 99.2 %, 99.1 %, 99.8 %, and 98.8 %, respectively, due to the synergy of strong coordination ability (Cl^-) and reduction (CA) in NDES. This work avoids the use of hazardous chemicals while achieving total leaching in a short period (30 min) at a low temperature (80 °C), achieving an efficient and energy-saving aim. It reveals that NDES has a high potential for recovering precious metals from cathode materials and offers a viable, environmentally friendly method of recycling used lithium-ion batteries (LIBs).

Comparative Study of the Dissolution of LCO in HCl Medium with and without H2O2

The dissolution of LiCoO2 (LCO) from spent lithium-ion batteries (LIBs) has been widely studied with organic and inorganic acids. Among these acids, HCl is the one that showed the best results when used at concentrations higher than 4 M. However, its higher cost compared with other acids is disadvantageous. Taking this into account, this work aims to perform a comparative study of the effect of different operational variables such as temperature, reaction time, leaching agent concentration (HCl) and reducing agent concentration (H2O2) on the dissolution efficiency of LCO for the systems HCl and HCl-H2O2 to determine the optimal parameters to achieve a maximum dissolution in minimum time at low temperatures and reagent concentrations. Increasing temperature, time and concentration of the reagents had a positive effect on the dissolution of LCO. When working with HCl 1.8 M, the highest dissolution for LCO, 91.0% was obtained at 348 K for 60 min. Furthermore, a slightly higher oxide dissolution (93.0%) was obtained in a reducing medium at the same temperature in half the time and with a concentration of HCl more than ten times lower. This will allow us to propose an alternative process to the existing ones with economic and ecological advantages.