Abstract
? 2022 Elsevier B.V.Layered P-type structures are integral to most competitive cathodes for sodium-ion batteries (SIBs). However, the performance of P2-type cobalt-based layered materials is unsatisfactory owing to a low initial discharge capacity caused by Na deficiency. Here, Mn-doped NaxCoO2 with a P3 structure is synthesized by using a modified solvent-thermal method with calcination. A structural analysis shows that partial Mn doping can effectively control P3 phase formation and increase D-layer spacing, thereby improving the diffusion of Na+. In addition, enhanced electrochemical performance is observed in optimized P3-type Na0.26Co0.48Mn0.52O2(NCMO-1), which exhibits a reversible specific capacity of 64 mAh g?1 at 3 A g?1 and a good capacity retention of 58% after 500 cycles. Furthermore, the Na-ion full cell constructed with an NCMO-1 cathode and a hard carbon anode yields a competitive energy density of 175.9 Wh kg?1 at 0.4 A g?1 with excellent cycle stability. Thus, this work provides a new viewpoint on the development of P3 structural materials with higher electrochemical performance for SIBs.
NSTL
Elsevier