Fe-As Intermetallic Alloys: A Way Out for Sodium-Ion Batteries

Abstract

Intermetallic alloy anodes with high theoretical sodiation capacities are highly sought for next-generation sodium-ion batteries (SIBs). Here, we demonstrate the fabrication of a high-performance intermetallic Fe-As alloy anode for high capacity sodium-ion batteries (SIBs) via a high-throughput and industrially viable melt-spinning process. This earth-abundant low-cost alloy anode exhibits highly enhanced cycling stability, retaining 96% of its 965 mAh·g-1 sodiation capacity after 400 cycles at 50 mA g-1 specific current for SIBs. The exceptional electrochemical performance of the prepared alloy anode is attributed to the crystalline features of the melt-spun fibers, which also enable a remarkable rate performance with ∼668 mAh g-1 sodiation capacity at 5 A g-1. We further demonstrated the application of the prepared alloy anode in a sodium-ion full-cell configuration, where it delivered a sodiation capacity of over 770 mAh g-1 (based on anode) at 50 mA g-1, achieving more than 97% Coulombic efficiency even after 200 cycles. Our results suggest that melt-spun alloy anodes hold great potential for realizing fully functional SIBs. © 2023 American Chemical Society.