PROCESS FOR THE PREPARATION OF BATTERY PRECURSORS

The invention concerns a process for the recovery of metals such as Ni and Co from a Li-containing starting material. In particular, this process concerns the recovery of metals M from a Li-containing starting material, wherein M comprises Ni and Co, comprising the steps of: Step 1: Providing said starting material, comprising Li-ion batteries or their derived products; Step 2: Removing Li in an amount of more than the maximum of (1) 30% of the Li present in said starting material, and (2) a percentage of the Li present in said starting material determined to obtain a Li:M ratio of less than 0.70 in a subsequent acidic leaching step; Step 3: Subsequent leaching using relative amounts of Li-depleted product and a mineral acid, thereby obtaining a Ni- and Co-bearing solution; and, Step 4: Crystallization of Ni, Co, and optionally Mn. Due to the lower reagent consumption and higher Ni and/or Co concentration during hydrometallurgical processing, the invention is an efficient and economic process for the production of crystals suitable for battery material production.