A Poriferous Nanoflake-Assembled Flower-Like Ni 5 P 4 Anode for High-Performance Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have been regarded as one of the most competitive alternatives for lithium-ion batteries (LIBs) due to the abundance of sodium and comparable electrochemical characteristics of sodium to that of lithium. However, while highly desired, developing stable anode materials remains a critical challenge. In this work, the development of a stable anode for SIBs is reported, a poriferous nanoflake-assembled flower-like nickel tetraphosphide (PNAF-NP) with high surface area and typical mesoporous property. Due to the unique structure, the PANF-NP anode exhibits excellent reversible capacity of 648.34 mAh g -1 at 0.2 A g -1 with a Coulombic efficiency of 98.67%, and superior cycling stability at 0.2 A g -1 with high retention capacity of 456.34 mAh g -1 and average Coulombic efficiency of 99.19% after 300 cycles. Moreover, the high reversible capacity of 614.43, 589.49, 512.66, and 432.23 mAh g -1 is achieved at 0.5, 1, 2, and 5 A g -1 , respectively, indicating the superior rate capability of the PNAF-NP anode. This work represents a great advancement in the field of SIBs by reporting a high-performance anode material.