The synthesis of shape-controlled crystals has been a highly attractive research topic in modern materials chemistry. In this work, the growth of Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 (NCM) crystals in molten sulfate or carbonate salts (flux) at 1000 °C was systematically studied under various conditions. In situ X-ray diffraction during the growth and thermogravimetry-differential thermal analysis revealed that the growth of NCM crystals in the flux was controlled by liquid-phase sintering according to the Ostwald ripening principle. We studied the effect of Na + in the flux on the crystal shapes and found that Na + was critical in forming octahedral crystals with well-developed facets. Single crystals with well-developed facets were obtained homogeneously from Na 2 SO 4, while truncated polyhedral crystals of smaller size were obtained from Li 2 SO 4 . The shape-controlled NCM crystals showed discharge capacities approaching 160 mAh g –1 in the operating voltage range of 2.8–4.4 V vs Li/Li + under a low current density of 0.1 C, independent of flux composition. This suggests that the Li + and transition-metal ions in the individual NCM crystals were highly ordered into hexagonal arrangements belonging to the R 3̅ m space group, without cation mixing.
No takes yet. Share an insight, caveat, or question.
Kimijima et al. (2016) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: