Shape‐Induced Kinetics Enhancement in Layered P2‐Na0.67Ni0.33Mn0.67O2 Porous Microcuboids Enables High Energy/Power Sodium‐Ion Full Battery

Abstract

AbstractP2‐type Na0.67Ni0.33Mn0.67O2 cathode material generally suffers from poor cycling and rate performance due to fiercely phase variation and low Na+ diffusion kinetic. Although efforts have been made to promote the electrochemical properties through ionic doping, the specific capacity reduction in most cases since the doped cations are electrochemical inactive cannot be neglected. Recently, some pioneering work have demonstrated that the advanced morphological design could significantly improve Na+ intercalation kinetics. But rare researches devote to improving the electrochemical performance on P2‐type Na0.67Ni0.33Mn0.67O2 through morphological manipulation. Herein, unique one‐dimensional P2‐type Na0.67Ni0.33Mn0.67O2 porous microcuboids with abundantly exposed {010} facets have been well designed via a simple one‐pot strategy. Due to the reasonable material design, it demonstrates unprecedented electrochemical performances. Particularly, it can deliver high rate performance with 122.1 mAh g−1 at 5 C, extraordinary cycle life with a capacity retention of 94.6 % after 1500 cycles at 5 C. More importantly, prototype sodium ion full cell could achieve state‐of‐the‐art power density of 1383.1 W kg−1 with high energy density of 84.7 Wh kg−1. The underlying mechanism of enhanced electrochemical properties of this well‐designed material has been deciphered through dynamic analysis, in‐situ X‐ray diffraction and structural analysis after cycling.