Environmental Impact of EV Batteries and Their Recycling

Electrifying transportation is one of the biggest keys to solving the looming climate crisis. The demand for electric vehicles (EV) is booming in the last five years and will increase in the coming years. In this modern age, where EV is the finest means of transportation due to null exhaust gases, there is a dire need to think about ways of recycling and reusing those batteries associated with EVs. In this context, it is estimated that post-vehicle battery packs application will be crossed from 1.4 million to 6.8 million by the year 2035. Numerous researches have been done on the re-purposing and safe disposal of EV batteries. However, presently, Lithium-ion batteries (LiBs) are the optimal choice for electric transportation due to greater energy density, compact size, and extended life cycles. Nonetheless, the trade-off between re-purposing and disposal of LiBs is substantial for the protection of the environment and human health. Regrettably, Lithium-ion battery recycling percentage is only 3% currently whereas its revival is negligible.

Selective cobalt and nickel electrodeposition for lithium-ion battery recycling through integrated electrolyte and interface control

Molecularly-selective metal separations are key to sustainable recycling of Li-ion battery electrodes. However, metals with close reduction potentials present a fundamental challenge for selective electrodeposition, especially for critical elements such as cobalt and nickel. Here, we demonstrate the synergistic combination of electrolyte control and interfacial design to achieve molecular selectivity for cobalt and nickel during potential-dependent electrodeposition. Concentrated chloride allows for the speciation control via distinct formation of anionic cobalt chloride complex (CoCl42-), while maintaining nickel in the cationic form ([Ni(H2O)5Cl]+). Furthermore, functionalizing electrodes with a positively charged polyelectrolyte (i.e., poly(diallyldimethylammonium) chloride) changes the mobility of CoCl42- by electrostatic stabilization, which tunes cobalt selectivity depending on the polyelectrolyte loading. This strategy is applied for the multicomponent metal recovery from commercially-sourced lithium nickel manganese cobalt oxide electrodes. We report a final purity of 96.4 ± 3.1% and 94.1 ± 2.3% for cobalt and nickel, respectively. Based on a technoeconomic analysis, we identify the limiting costs arising from the background electrolyte, and provide a promising outlook of selective electrodeposition as an efficient separation approach for battery recycling.