• Coprecipitation of ternary hydroxide
• Lithium-ion batteries
• Leaching of NMC 111

Batteries are becoming key to the energy transition towards a more sustainable future because of their role in the electrification of transport, industry, and homes. Their use will eliminate vehicular emissions of CO2 and NO2 in a world struggling with climate change. Electric vehicle (EV) technology seems to be progressing faster than expected and industry forecasts are regularly revised upwards. However, the growth in demand for batteries has raised raw material prices and given rise to concerns about potential shortages of cobalt, nickel, manganese, and lithium. Indeed, the technology behind electric vehicles is the lithium-ion battery (LIB), particularly NMC (LiNi1/3Mn1/3Co1/3O2). The continuous demand for EVs must be supported by adequate recycling facilities in order not to lose the ecological benefits of switching to electric mobility.
In this thesis work we will focus on the waste hydrometallurgical process, in particular on the leaching and coprecipitation steps.
For the first step, the objective will be to analyze the effect of four factors (sulphuric acid concentration, hydrogen peroxide concentration, solid-to-liquid ratio (S/L) and time) on the leaching of NMC 111. The study will be carried out using the Design of Experiment software, which will make it possible to establish the optimum conditions for this phase. This study will lead to the understanding that yields of about 100% can be achieved when operating under appropriate conditions. The most appropriate conditions for leaching NMC 111 are a slight excess of sulphuric acid and hydrogen peroxide (3.06 M and 2.5 vol.% respectively) with an S/L ratio of 99.8 g/L and time of 62 minutes.
This will be followed by the coprecipitation phase, which will lead to the formation of ternary hydroxide of nickel, manganese, and cobalt. The aim will be to study the factors influencing this process, starting with a solution replicating our leachate. Through analysis of the precipitate, we will try to understand the influence of these factors on the structural morphology and chemical composition. The study has yielded encouraging results in that by comparing the tests carried out we have understood which factors are most influential on this process (concentration of metal sulphate, concentration of chelating agent and time).