Dynamic localized domains of metallic glasses enable high-capacity SbBi anode for potassium ion batteries

Abstract

Alloys with metallic glasses (MG) is a promising strategy to overcome the challenges, including severe volume expansion, sluggish kinetics, and limiting capacity, as anodes for potassium-ion batteries (PIBs). However, excessive MG will lead to low Coulombic efficiency and poor cycling stability. Here, we propose model of deformation-induced dilatation to construct the dynamic localized domains of MG to control the amorphization degree. By selecting the dual-intermetallic Cu2Sb@SbBi2 heterojunctional composite as anode for PIBs, the advantages of dynamic localized domains of MG are well proved. The interface between intercalation-type Cu2Sb and alloy-type SbBi2 will generate huge dilatation entanglement owing to the huge difference in volume variety deriving from two distinctive potassiation/depotassiation behaviours of heterojunction. As a result, the dynamic localized domains of MG are generated owing to the deformation-induced dilatation mechanism. Benefiting from this distinctive feature with dynamic localized domains of MG, the Cu2Sb@SbBi2 anode delivers a high reversible capacity of 672 mAh g-1 and an initial Coulombic efficiency of 84.6%. This work demonstrates a dynamic localized domains amorphization regulation engineering approach to achieve high-performance alloy anodes for PIBs.