Improving the stability of P2-type NaMn2/3Ni1/3O2 via phasic intergrowth induced by Li-ion substitution. (July 2022)

• Record Type: Journal Article
• Authors: Huang, Fengbin; Ge, Yilin; Cheng, Hua; Wang, Feng; Yao, Qingrong; Chen, Zhenhua; Lu, Zhouguang; Deng, Jianqiu
• Is Part Of: Materials today energy. Volume 27(2022)
• Publication Date: 2022-07
• Subjects: Sodium-ion batteries -- Manganese-rich cathode -- P2-type layered oxides -- Long life -- Air stability; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2022.101041
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Layered transition metal oxides are attractive cathode materials for sodium-ion batteries but are largely hindered by the low capacity and poor cycling stability. Herein, Na is substituted by Li to enhance the capacity and stability of Na1- x Li x Mn2/3 Ni1/3 O2 . It is found that Li substitution can provide robust structure benefiting from contracted adjacent transition metal layers owing to strong bonding property of O–Li–O and incremental inactive Mn 4+ . So it follows that noxious Mn 3+ Jahn-Teller distortion and slabs slipping are mitigated. Also, the presence of "Li pillar" disturbs the Na + /vacancies and transition metal ordering during Na extraction, preventing phase transformation during deep desodiation process. Consequently, the Na1- x Li x Mn2/3 Ni1/3 O2 demonstrates high capacity, remarkable rate capability, and long-term cycling life. Among them, Na0.8 Li0.2 Mn2/3 Ni1/3 O2 cathode delivers a discharge capacity of 115.3 mA h/g, with a capacity retention of 86.0% after 100 cycles. This simple strategy to stabilize the layered structure oxides is inspiring to design high-performance cathode materials for sodium-ion batteries. Graphical abstract: Image 1 Highlights: The presence of Li disturbs the Na + /vacancy and TM ordering, thus relieving the phase transformation upon Na + extraction. Li-substituted samples with shrinking interlayer still show fast ion motion, which caused by reduced diffusion barrier. Compared to Li-free sample, Li-substituted ones possess better water resistance and air stability after aging treatment.