Facile and large-scalable synthesis of low cost hard carbon anode for sodium-ion batteries

Although hard carbons are considered to be applied as promising anode materials for sodium-ion batteries (SIBs) with improved specific capacity and good long-term cycle life. However, a significant low initial Coulombic efficiency (ICE) and high cost that consequently impede its use in future commercialization of SIBs. Herein, a cost effective strategy is used to prepare the large-scalable hard carbon (HC) anode material for SIBs, which shows excellent initial reversible capacity of 308 mA h g−1 under the current rate of 50 mA g−1 and considerable higher ICE of 78%. After more than 300 cycles, the material exhibits a specific capacity of 160 mA h g−1 and presenting superior capacity retention more than 94% under current density of 500 mA g−1. The obtained results establish a new technique to construct low cost hard carbon based anode materials for next-generation high performance SIBs.