Single-phase P2-type layered oxide with Cu-substitution for sodium ion batteries

摘要

cqvip:The development of high-performance layered oxide cathodes for sodium ion batteries (SIBs) continues to facing be hindered by severe challenges to date.Herein,a single-phase P2-Na0.67Mn0.6Ni0.2Co0.1Cu0.1O2(NMNCC) comprising multiple-layer-oriented stacked nanoflakes is designed and synthesized via a simple sol-gel method.The large lattice parameters ensure a large three-dimensional frame,which enables the diffusion of sodium ions.Owing to its optimal morphology structure modulation transition metal substitution strategy,the MNCC electrode delivers a reversible capacity of 131.3 mAh g^-1 at 0.1 C with retention of 86.7%after 200 cycles.In addition,it provides an initial capacity of 86.7 mAh g^-1,and a retention of 80.0%after 500 cycles even at a current density of up to 1 A g^-1.The stable single-phase structure and slight volume shrinkage observed after Na+extraction further delay structural degradation.High Na+mobility and low Na+diffusion resistance are also guarantee the excellent rate performance of the NMNCC electrode.Thus,we determine that the NMNCC cathode is significant in the advancement of promising novel layered oxide cathodes.