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

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 degrees C), 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.