Yuan Shenghua, Ren Chengwen, Liu Ziwei, Chen Yu, Wang Wenhui
College of Chemistry and Materials Science, Langfang Normal University, 100 Aimin West Road, Langfang 065000, China.
Key Laboratory of Display Materials and Photoelectric Devices (MOE), School of Materials Science and Engineering, Tianjin University of Technology, 391 Binshui Road, Tianjin 300384, China.
Nanomaterials (Basel). 2025 Jul 1;15(13):1017. doi: 10.3390/nano15131017.
Lithium-rich layered oxide (LLO) has received extensive attention from researchers due to its high initial discharge capacity (≥250 mAh g). However, defects such as its high initial irreversible capacity, voltage decay, and poor rate performance have severely limited its commercialization. These issues arise because the LiMnO component in LLO is activated during the initial cycle, leading to the participation of lattice oxygen anions (O) in redox reactions. This results in irreversible oxygen loss (O) and subsequent structural phase transitions. To address these challenges, this study focuses on Li.Ni.Co.Mn.O as the host material, utilizing abundant exposed (010) plane secondary particles and employing a vanadium (V) doping strategy to enhance electrochemical performance. The V forms strong V-O bonds with the lattice oxygen, effectively suppressing irreversible oxygen loss and improving structural stability. The results demonstrate that the LLO achieves the best electrochemical performance as the doping amount is 1 mol%, and the capacity retention improves from 74.5% (undoped) to 86% (V-doped) after 140 cycles at 0.5 C.
富锂层状氧化物(LLO)因其高初始放电容量(≥250 mAh g)而受到研究人员的广泛关注。然而,其高初始不可逆容量、电压衰减和倍率性能差等缺陷严重限制了其商业化。这些问题的出现是因为LLO中的LiMnO成分在初始循环中被激活,导致晶格氧阴离子(O)参与氧化还原反应。这导致不可逆的氧损失(O)和随后的结构相变。为应对这些挑战,本研究聚焦于Li.Ni.Co.Mn.O作为主体材料,利用大量暴露的(010)面二次颗粒,并采用钒(V)掺杂策略来提高电化学性能。V与晶格氧形成强V-O键,有效抑制不可逆氧损失并提高结构稳定性。结果表明,当掺杂量为1 mol%时,LLO实现了最佳的电化学性能,在0.5 C下循环140次后,容量保持率从74.5%(未掺杂)提高到86%(V掺杂)。