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 (D-K) of FeSe@C is 1.67 x 10(-10)cm(2)s(-1)is calculated. Therefore, the FeSe@C composite is expected to become the next-generation anode material for PIBs.