Single-crystal processing of layered oxide cathode has received great attention recently. It has been recognized that Ni-rich layered oxide with grain size in mm range tends to provide better cycling performance due to better structural integrity against volume changing during charge/discharge cycles.

However, during heating/calcination process of oxide/carbonates/nitrates powder compacts, it may involve decomposition, chemical reactions, diffusion, oxidation, sintering, grain-growth.

For grain growth to take place at final stage of sintering, the powder compacts need to be heated to higher temperatures for certain period of time. On the other hand, the formation of Ni-rich layered oxides need air/oxygen for Ni oxidation and better crystallization. Thus, it is crucial to investigate the processing of single-crystal Ni-rich layered oxide based on the sintering behavior, thermal gravimetric analysis, and phase transformation. Furthermore, the lithiation/oxidation of Ni-containing oxides during single-crystal processing may involve charge compensation resulted from defect reactions. In this study, the affected electrical, optical, structural, and electrochemical properties of layered oxides will be discussed based on defect chemistry consideration. The structural, microstructural and electrical properties of decomposed precursors and doped layered oxides will be examined using XRD, SEM and DC/AC impedance measurements. CV and charge/discharge tests from assembled coin cells will be used to evaluate electrochemical properties of single-crystal Ni-rich layered oxides.