KCo_xMn_1-x[Fe(CN)₆]/Carbon nanotube composite as high capacity anode for Li-ion batteries

To explore inexpensive electrode materials with high energy density is urgent for developing next generation Li-ion batteries (LIBs). In this paper, a multi-metal Prussian blue analogue composited with carbon nanotube (KCo_xMn_1-x[Fe(CN)₆]/CNT), synthesized via a simple solution precipitation method, is employed as the anode for LIBs, which exhibits superior electrochemical performance. When cycled at 0.1 A g⁻¹, it delivers the reversible capacity up to 727.5 mA h g⁻¹ during initial de-lithiation. In addition, this material presents excellent rate capability, yielding 452.3 and 408.7 mA h g⁻¹ at 1 and 2 A g⁻¹, respectively. The improved performance may be associated with the effective connection between CNT and CoMnHCF particles to enhance the charge-transfer kinetics and lower the electrical resistance. Regarding the charge/discharge mechanism, the full reduction of Co²⁺, Mn²⁺ and Fe²⁺ in the initial lithiation process and the redox of Fe₂O₃/Fe⁰, CoO/Co⁰, MnO/Mn⁰ in the subsequent cycles is proposed.