| 초록 |
This study presents a strategy for improving the cycling stability of O3-type layered Na[Ni0.5Mn0.5]O2 (NM) cathode materials via Sn introduction. Different amounts of Sn (0.5, 1, and 3 mol%) were coated on the hydroxide precursor by a wet method to uniformly introduce Sn into the particles. The cycling stability of the NM cathode with 1 mol% Sn (Sn1-NM) was improved, maintaining 84.9% of its initial capacity after 100 cycles and ~15% higher than that of the bare NM cathode. The improvement in cycling stability is attributed to the introduced Sn, which mitigates structural distortions caused by monoclinic phase transitions and suppresses abrupt contraction in the highly charged state. In addition, the precipitated Sn nanoparticles on the cathode surface protect the internal primary particles from parasitic attacks by the infiltrated electrolyte. The proposed strategy provides an effective method to improve the cycling stability of O3-type layered cathodes for SIBs by modifying their morphology and inhibiting deleterious electrolyte attacks. |
