Metal-organic framework-derived Co0.85Se nanoparticles in N-doped carbon as a high-rate and long-lifespan anode material for potassium ion batteries

Metal-organic frameworks (MOFs)-derived metal chalcogenides/carbon, has been developed as promising anode materials for lithium/sodium ion batteries. However, they are not explored for potassium-ion batteries yet. Here, ZIF-67 is employed as a self-sacrificed template to synthesize Co 0.85 Se nanoparticles in N-doped carbon as an anode material for potassium-ion batteries. In this composite, N-doped carbon enhances the electron conductivity, cushions the volume change and inhibits the aggregation of Co 0.85 Se upon cycling. Meanwhile, mesoporous structure shortens the diffusion distance of potassium ions , as well as increases the contact between electrolyte and electrode. These features endow this composite superior performances. It delivers a specific capacity of 114.7 mA h g −1 at 1000 mA g −1 after 250 cycles. At 2.0 A g −1 , the specific capacity still maintains at 110.7 mA h g −1 . The electrochemical performances of full cells based on Co 0.85 Se@NC as an anode material are also investigated. The result greatly spurs the exploration of metal chalcogenides as anode materials for potassium ion batteries .