3D carbon framework-supported FeSe for high-performance potassium ion batteries†
FeSe@C with a 3D porous interconnected carbon framework is used as the anode for potassium ion batteries (PIBs). FeSe@C has a relatively large specific surface area and a superior microporous and mesoporous structure, thus facilitating the storage and transportation of potassium ions. When tested in PIBs as an anode, FeSe@C shows good specific capacity of 298.5 mA h g−1 after 200 cycles at 500 mA g−1, thus indicating good cycle stability. In addition, a possible potassium storage mechanism is explored. Moreover, the diffusion coefficient of potassium ions (DK) of FeSe@C is 1.67 × 10−10 cm2 s−1 is calculated. Therefore, the FeSe@C composite is expected to become the next-generation anode material for PIBs.