Fast energy storage performance of CoFe2O4/CNTs hybrid aerogels for potassium ion battery

We report CoFe 2 O 4 and carbon nanotubes hybrid aerogels as a novel anode material for potassium ion batteries (KIBs). The synthetic route take the advantage of marine biobased materials as the precursor and facilely produce large-scale production of hybrid CoFe 2 O 4 and carbon nanotubes aerogels as the advanced anode. The hybrid aerogels deliver a remarkable capacity of 180 mAh g −1 with high stability over 200 cycles at a current density of 0.1 A g −1 . The high rate charge/discharge reveals a relatively high capacity of 83 mAh g −1 even at the current density of 1.0 A g −1 . In-situ XRD investigations reveal the phase evolution during charge/discharge, demonstrating the high stability of hybrid aerogels for the potassium intercalation/extraction. The high specific surface area and large numbers of mesopores with more active sites can benefit the effective transmission of electrons and K ions , leading to an improved specific capacity and cycle stability.