An insight into the influence of crystallite size on the performances of microsized spherical Li(Ni_0.5Co_0.2Mn_0.3)O₂ cathode material composed of aggregated nanosized particles

Relationships between the performance and the crystallite size of the microsized spherical Li(Ni_0.5Co_0.2Mn_0.3)O₂ cathode material composed of aggregated nanosized primary particles have been comprehensively studied. The cathode material was synthesized by a high-temperature solid-state method. The results obtained by XRD, Rietveld refinement, SEM, HR-TEM, DSC, and galvanostatic test show that the crystallite size (XS) of Li(Ni_0.5Co_0.2Mn_0.3)O₂ is greatly affected by the temperature in the range of 750 to 820 °C. Most of all, the crystallite size plays a unique role in the performance of the material. That is, the electrochemical characteristics of Li(Ni_0.5Co_0.2Mn_0.3)O₂, such as discharge capacity, rate performance, and thermal stability, are closely related to the crystallite size. Furthermore, the retention of discharge capacity is determined by that of crystallite size in Li(Ni_0.5Co_0.2Mn_0.3)O₂ after 100 cycles.