Direct implementation of K3Fe(CN)6 as cathode materials of sodium-ion batteries

Transition metal cyanides are considered as a promising cathode candidate of sodium-ion batteries. Herein, we reported a direct implementation of commercial K 3 Fe(CN) 6 (KFC) as active cathode material of SIBs by a simple recrystallization method. Our results suggest that by integrating conductive carbons (SuperP, abbreviated as SP) and multi-walled carbon nanotubes (CNTs) with KFC, an efficient conducting network could be well established for the utilization of KFC active components, thereby endows excellent cyclic and rate performances. Specifically, the KFC/SP/CNTs composite delivers its theoretical capacity of 81 mAh g −1 at 0.1C, and a reversible capacity of 75.6 mAh g −1 at 1C which maintains 62.6 mAh g −1 after 500 cycles. At ultrahigh rate of 12C, the capacity retention can reach 68% of initial. Our effort suggests that direct implementing industrial KFC as cathode materials for SIBs is highly feasible, which may provide a low-cost cathode candidate of sodium-ion batteries for large-scale energy storage.