Selective cobalt-exchange membranes for electrodialysis dedicated for cobalt recovery from lithium, cobalt and nickel solutions

Prediction of metal recovery potential of end-of-life NEV batteries in China based on GRA-BiLSTM

As Chinese new energy vehicle (NEV) sales continue to grow, end-of-life batteries have great potential for recycling in the future. In this study, a combined model based on Gray Relation Analysis and Bi-directional Long Short-Term Memory (GRA-BiLSTM) is proposed for predicting NEV sales, and the NEV battery life is modeled using the Weibull distribution. Then, the amount of end-of-life batteries, secondary utilization and metal recycling are calculated. The impact of end-of-life battery recycling on the supply and demand of key metals is studied. The results show that in 2040, the secondary utilization of end-of-life batteries in the Standard Growth Rate-Lithium Iron Phosphate Battery Dominated-High Secondary Utilization rate scenario (SGR-LFPH) is 391.76 GWh. The recycling volumes of lithium, nickel and cobalt are 45,900 tons, 92,900 tons and 22,100 tons, respectively. In the Standard Growth Rate-lithium nickel cobalt manganese oxide Battery Dominated-Low Secondary Utilization rate scenario (SGR-NCML), the recycling of lithium, nickel and cobalt is even greater, at 62,600 tons, 372,200 tons and 71,700 tons, respectively. End-of-life batteries recycling can reduce the demand for metals. However, as NEV sales continue to grow, the gap between metal supply and demand remains significant. The findings urge the Chinese government develop appropriate battery management strategies to increase the recycling rate of end-of-life batteries; and to encourage enterprises to research new types of batteries to resolve the conflict between supply and demand for metals.

Selective electrodialysis process for the recovery of potassium from multicomponent solution systems

Selective electrodialysis is a promising approach to recovering K+ from complex coexisting ionic systems. In this study, the effects of current density, the concentration of K+ and Mg2+, as well as the operating temperature on the separation process of K+ and Mg2+ were explored to investigate the competitive migration of mono- and multivalent ions, offering a guide for the design of selective electrodialysis process, and therefore obtain the desired aqueous solutions containing K+ and Mg2+. The results show that ion concentration played a critical role in determining the selectivity of separation between K+ and Mg2+. High concentrations of K+ and Mg2+ led to a decrease in selectivity but the effect of concentration of K+ on selectivity was more pronounced. Although higher current density increased the flux of ions, their impact on separation selectivity was minimal. Furthermore, higher temperature increased the flux of ions but resulted in a decrease of K+ proportion in the solution. Overall, this study provides good guidance for studying the competitive migration of mono- and multivalent ions and the high-value recycling of potassium resources.

Application of Hybrid Electrobaromembrane Process for Selective Recovery of Lithium from Cobalt- and Nickel-Containing Leaching Solutions

New processes for recycling valuable materials from used lithium-ion batteries (LIBs) need to be developed. This is critical to both meeting growing global demand and mitigating the electronic waste crisis. In contrast to the use of reagent-based processes, this work shows the results of testing a hybrid electrobaromembrane (EBM) method for the selective separation of Li⁺ and Co²⁺ ions. Separation is carried out using a track-etched membrane with a pore diameter of 35 nm, which can create conditions for separation if an electric field and an oppositely directed pressure field are applied simultaneously. It is shown that the efficiency of ion separation for a lithium/cobalt pair can be very high due to the possibility of directing the fluxes of separated ions to opposite sides. The flux of lithium through the membrane is about 0.3 mol/(m² × h). The presence of coexisting nickel ions in the feed solution does not affect the flux of lithium. It is shown that the EBM separation conditions can be chosen so that only lithium is extracted from the feed solution, while cobalt and nickel remain in it.

Polymer Membranes as Innovative Means of Quality Restoring for Wastewater Bearing Heavy Metals

The problem that has aroused the interest of this review refers to the harmful effect of heavy metals on water sources due to industrial development. In this respect, the review is aimed at achieving a literature survey on the outstanding results and advancements in membranes and membrane technologies for the advanced treatment of heavy metal-loaded wastewaters. Particular attention is given to synthetic polymer membranes, for which the proper choice of precursor material can provide cost benefits while ensuring good decontamination activity. Furthermore, it was also found that better removal efficiencies of heavy metals are achieved by combining the membrane properties with the adsorption properties of inorganic powders. The membrane processes of interest from the perspective of industrial applications are also discussed. A noteworthy conclusion is the fact that the main differences between membranes, which refer mainly to the definition and density of the pore structure, are the prime factors that affect the separation process of heavy metals. Literature studies reveal that applying UF/MF approaches prior to RO leads to a better purification performance.