Electrochemical performance of ultra-high‑nickel layered oxide cathode synthesized using different lithium sources

Ultra-high‑nickel layered oxide cathodes are extensively explored in lithium-ion battery research owing to their high specific capacity. However, the rapid decline in discharge specific capacity considerably limits their long-term performance. The choice of lithium precursors is crucial in enhancing both the structural and cycle stability of these batteries, yet this aspect has not been adequately addressed in existing studies. In this study, Li₂O, LiOH, and Li₂CO₃ were used as lithium precursors to synthesize LiNi_0.92Co_0.04Mn_0.04O₂ (NCM92) cathodes. We compare the structure and electrochemical properties of NCM92 cathode materials prepared with these three lithium precursors, examining a lithium residual layer on the surface of three NCM92 and thus inferring the varying amounts of Li incorporation into the bulk lattice. Our findings highlight the effect of lithium precursors on the rapid degradation of NCM92's discharge capacity. Notably, the NCM92–Li₂O cathode demonstrates a higher discharge specific capacity and superior capacity retention after 100 cycles compared to cathodes synthesized with LiOH and Li₂CO₃. This study provides valuable insights and guidance for further research on ultra-high‑nickel layered oxide cathode materials.