Influence of sintering temperatures on microstructure and electrochemical performances of LiNi0.93Co0.04Al0.03O2 cathode for high energy lithium ion batteries

Abstract

In this study, we present a method for synthesizing Ni-rich LiNi0.93Co0.04Al0.03O2 (NCA) with a high-energy cathode material by the solid-phase method. The sintering temperature plays a very important role in the electrochemical performance of the LiNi0.93Co0.04Al0.03O2 since it affects the crystallinity and structural stability. Therefore, various sintering temperatures (660 °C/690 °C/720 °C/750 °C/780 °C/810 °C) are studied to get optimum electrochemical performances. The electrochemical performance of LiNi0.93Co0.04Al0.03O2 sintered at 720 °C shows the highest discharge capacity of 217.48 mAh g−1 with excellent Coulombic efficiency of 87.84% at 0.1 C. Moreover, the LiNi0.93Co0.04Al0.03O2 sintered at 720 °C exhibits excellent rate-capability (181.1 mAh g−1 at 2.0 C) as well as superior cycle stability (95.4% after 80 cycles at 0.5 C). This is because optimized sintering temperature leads to good structural stability with low cation disorder and residual lithium content.