Controlled scalable synthesis of yolk‐shell antimony with porous carbon anode for superior Na‐ion storage

Abstract

Abstract Antimony (Sb) anodes explored for high energy density sodium cells are prone to rapid capacity decay during (de)alloying owing to reversible phase transformation (Sb⇌Na3Sb) induced volume expansion necessitates rationale materials and electrode design. Herein, we design a yolk‐shell structure where surfactant‐stabilized and pH modulated Sb nanoparticles (SbNPs) are carefully coated with Stöber silica and resorcinol‐formaldehyde resin at room temperature. Upon pyrolysis under argon followed by careful etching of the intermediate layer from Sb@SiO2@C double core‐shell leads to the formation of Sb@void@C yolk‐shell possessing SbNPs confined within mesoporous conductive carbon shells with sufficient void space allowing Sb to realize its full potential and display superior sodium storage behavior. Moreover, binder‐free electrodes fabricated by electrophoretic deposition deliver superior performance in a sodium cell with improved rate capability. A full cell fabricated with Prussian blue type NaxFe[Fe(CN)6] cathode paired with Sb@void@PC anode delivers a practical energy density of ∼142 Whkg–1 operating at ∼1.95 V. The favorable results of yolk‐shell Sb@void@C anodes in sodium‐ion battery demonstrate the structural superiority for future energy storage applications

Keywords

• anode
• antimony
• porous carbon
• sodium‐ion batteries
• yolk‐shell