<p>The growing global demand for cathode materials, driven by the rapid expansion of electric vehicle production and renewable energy storage systems, has significantly increased the need for critical metals such as nickel and cobalt. The production of mixed hydroxide precipitate (MHP) is essential. Managing manganese and magnesium precipitation is crucial, as high concentrations of these impurities considerably raise the expenses during solvent extraction. Hydroxide precipitation was selected due to its simpler process, lower operational costs compared to sulfide precipitation, no H₂S gas required, and better alignment with industrial requirements. A thermodynamic analysis demonstrated that optimization could be achieved by controlling pH levels with the optimal operating range determined through the construction of concentration-pH diagrams for the -Ni²⁺, -Co²⁺, -Mn²⁺, -Mg²⁺, and -H₂O at 298&#xa0;K system. The results revealed that the operation window for the precipitation process at 25&#xa0;°C is around 6.0–8.4. Optimizing pH, residence time, and temperature precipitation parameters is essential for maximizing the efficiency of MHP precipitation; the effect of nitrogen addition on manganese suppression was evaluated. A longer residence time indicates that nickel and cobalt can redissolve into the solution, while manganese undergoes increased because of oxidative precipitation. A significant challenge in using sodium hydroxide as a precipitating agent for MHP is the issue of local over-alkalinity, which promotes the unwanted co-precipitation of manganese. Precipitating with nitrogen can minimize the oxidation problem, resulting in more stable cobalt content and lower manganese content. The MHP precipitation with sodium hydroxide follows a first-order reaction, exhibiting an activation energy of 5.42&#xa0;kJ/mol.&#xa0;</p>