A new method for direct synthesis of Li2CO3 powders by membrane electrolysis

Abstract

A new method for the direct synthesis of Li2CO3 powders by membrane electrolysis from LiCl solution is demonstrated in this paper, where a novel electrolysis system combining ventilation, agitation and loop filtration functions was reported. The aim of this work is to explore the effect of the starting concentration of LiCl on the phase and micromorphology of Li2CO3 crystals and thereafter to explore the mechanism of crystallization and grain growth law. Scanning electron microscopy (SEM) images indicate that the particles become irregular polycrystalline from well-defined flower-like and the micro-crystals change from lamellar to needle-like and subsequently to smaller globular granules, and the surface of the crystals becomes smooth with LiCl concentration increasing from 50 to 400 g·L−3. The crystalline phases of the different samples were characterized using powder X-ray diffraction (XRD) and the results prove that pure Li2CO3 crystals can be obtained in a single step by the electrolysis method. The particle size distributions show that both volume mean crystal sizes and the full width at half maximum (FWHM) decrease when the starting LiCl concentration increases from 50 to 300 g·L−3 and also decreases from 400 to 300 g·L−3.