Enhanced Na-Ion Storage of the NASICON Cathode through Synergistic Bulk Lattice Modulation and Porous Architecture

A NASICON-type Na3V2(PO4)(3) cathode, known for its stable three-dimensional Na+ diffusion channels, has been recognized as a prevailing candidate for sodium-ion batteries. However, the practical implementation of this cathode has been hindered by severe capacity degradation and inferior rate capability, resulting from its intrinsic poor electronic conductivity. Here, this work reports Ni2+ doping Na3V2(PO4)(3) materials accompanied by hierarchical porous morphology to strengthen ion migration and improve electronic conductivity. Owing to the porous structure and lattice modulation, the as-synthesized material displays a large surface area, short transport distance, easy electrolyte infiltration, and rapid electron/ion transportation. These multiple effects contribute to the superior rate and cycling stabilities of the modified NVP compared to those of its bare counterpart. When explored as a cathode for SIB, the NVP-Ni0.05 exhibits impressive rate capability (88.1 mAh g(-1) at 20C) and excellent cycling stability (93.8% capacity retention after 1500 cycles at 10C). This study provides a feasible strategy for developing a high-rate and long cycle-life electrode material and could motivate researchers to develop other sodium-based cathode materials.

Automated summary

This work presents a modified NASICON-type Na3V2(PO4)(3) cathode material for sodium-ion batteries, with Ni2+ doping and hierarchical porous morphology design to enhance ion migration and improve electronic conductivity. The as-synthesized material exhibits large surface area, short transport distance, easy electrolyte infiltration, and rapid electron/ion transportation, resulting in superior rate capability and cycling stability compared to the bare counterpart. The NVP-Ni0.05 cathode shows impressive rate capability (88.1 mAh g(-1) at 20C) and excellent cycling stability (93.8% capacity retention after 1500 cycles at 10C). This study provides a feasible strategy for developing high-rate and long cycle-life electrode materials and may inspire research into other sodium-based cathode materials.