Hierarchical Sb-Ni nanoarrays as robust binder-free anodes for high-performance sodium-ion half and full cells

摘要

A novel hierarchical electrode material for Na-ion batteries composed of Sbnanoplates on Ni nanorod arrays is developed to tackle the issues of the rapidcapacity fading and poor rate capability of Sb-based materials. The three-dimensional （3D） Sb-Ni nanoarrays as anodes exhibit the synergistic effects ofthe two-dimensional nanoplates and the open and conductive array structureas well as strong structural integrity. Further, their capacitive behavior isconfirmed through a kinetics analysis, which shows that their excellent Na-storageperformance is attributable to their unique nanostructure. When used asbinder-free sodium-ion battery （SIB） anodes, the nanoarrays exhibit a highcapacity retention rate （more than 80% over 200 cycles） at a current density of0.5 A.g-1 and excellent rate capacity （up to 20 A·g^-1）, with their capacity being580 mAh-g-1. Moreover, a P2-Na2/3Nil/3Mn2/302//3D Sb-Ni nanoarrays full celldelivers a highly reversible capacity of 579.8 mAh.g-1 over 200 cycles and an energydensity as high as 100 Wh-kg^-1 This design strategy for ensuring fast and stableNa storage may work with other electrode materials as well.