Reactive crystallization of Li2CO3 in LiOH/KOH solutions: solubility, nucleation and carbonization

Abstract

Lithium carbonate (Li₂CO₃) is essential for lithium-ion battery production, which is pivotal for the advancement of new energy technologies. While extensive research has been conducted on Li₂CO₃ crystallization in neutral solutions, there is a notable gap in understanding its behavior in alkaline environments, which could enhance the efficiency of its production. This study addresses this gap by investigating the reactive crystallization of Li₂CO₃ from LiOH/KOH mixed solutions. The solubility, nucleation, and carbonation processes of Li₂CO₃ in KOH solution were determined. Increasing temperature and decreasing KOH concentration would reduce the solubility of Li₂CO₃. Furthermore, higher temperatures were found to accelerate Li₂CO₃ precipitation and improve lithium recovery rates, achieving an 85.68% recovery with high crystallinity and purity of 98.4% at 363.15 K. The optimized temperature and KOH concentration can significantly enhance Li₂CO₃ crystallization in alkaline solutions. This advancement addresses a critical knowledge gap and provides a valuable reference for the recycling of lithium resources as well as the development of novel preparation processes.