Highly reversible sodium storage in a GeP5/C composite anode with large capacity and low voltage

GeP₅/C nanocomposite synthesized by a facile ball-milling method can deliver a highly reversible sodium storage capacity of 1250 mA h g⁻¹, a first coulombic efficiency of 93%, and a low average redox potential of 0.4 V vs. Na⁺/Na with smooth charge/charge plateaus, suggesting its promising application as a new anode for emerging SIBs.