Understanding the Effects of Bi Modification on the Properties of Ni‐Rich Cathodes

Abstract With the skyrocketing market demands for energy storage, lithium ions batteries (LIB) with higher energy density are urgently needed. Cathodes play a critical role in determining the energy density of LIB, and the most popular one is Ni‐rich cathode due to its high capacity. However, due to the fast structural degradation, Ni‐rich cathode materials should be further modified to achieve higher stability. Herein, we introduce bismuth ions in LiNi 0.83 Co 0.11 Mn 0.06 O 2 cathodes by adding Bi 2 O 3 during sintering to optimize the specific capacity and cycle stability. By adding 0.1 % mol Bi, the Li + diffusion and structural stability are effectively optimized, leading to improved electrochemical performances. The modified sample delivers much higher specific capacity (222.9 mAhg −1 , 0.05 C) than unmodified sample (204 mAhg −1 , 0.05 C). Meanwhile, the specific capacity of optimized sample after 100 cycles at 0.33 C is 27.75 mAhg −1 higher than that of unmodified sample. Therefore, this work demonstrates that Bi modification can be regarded as a possible solution to optimizing the electrochemical performance of Ni‐rich cathodes.