Construction nasicon-type NaTi2(PO4)3 nanoshell on the surface of P2-type Na0.67Co0.2Mn0.8O2 cathode for superior room/low-temperature sodium storage

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2020-12, Vol.402, p.126181, Article 126181
• Main Authors: Li, Yong, Shi, Qinhao, Yin, Xiupin, Wang, Jing, Wang, Juan, Zhao, Yufeng, Zhang, Jiujun
• Format: Article
• Language: English
• Subjects: Coating; Low temperature; Manganese base cathode; Nasicon–type NaTi2(PO4)3; Sodium ion battery
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.126181

(a) The interface model of NCM@NTP7 material, (b) GITT curves of NCM@NTP7 material, (c) The cycle performance of NCM @NTP7 at −20℃. [Display omitted] •Nasicon-type NaTi2(PO4)3 nanoshell is coated on the surface of P2-type Na0.67Co0.2Mn0.8O2.•Long cycle durability and high rate capacity are achieved for NCM@NTP7 at both room temperature and low temperature.•The bulk structure can be stabilized via the absolute solid-solution reaction at low temperature. P2-type manganese-based layered oxides are considered as promising cathode materials for sodium-ion batteries (SIBs). However, most of them suffer from sluggish kinetics and unfavorable structural stability, severely impeding their practical applications. Herein, Nasicon-type NaTi2(PO4)3 (NTP) nanoshell is coated on the surface of P2-type Na0.67Co0.2Mn0.8O2 (NCM) to boost its performance as a novel cathode for SIBs. The as-prepared NCM@NTP7 exhibits smooth electrochemical charge/discharge profiles, with a specific capacity of 70.7 mAh/g at 20C, and 86.7% capacity retained at 0.5C after 150 cycles at room temperature. Impressively, the bulk structure can be stabilized via the absolute solid-solution reaction at low temperature (-20℃), which shows 120.9 mAh/g discharge capacity at 0.2C with 92.3% retention and fast Na+ transport kinetic, wherein the D value is 16 times as large as that of pristine NCM. Our study provides a simple and efficient strategy to design and optimize promising layer-structural cathodes for SIBs.