Highly Dispersed ZnSe Nanoparticles Embedded in N-Doped Porous Carbon Matrix as an Anode for Potassium Ion Batteries

Advanced nanostructured functional materials obtained from the precursors of metal-organic frameworks show several unique advantages, including plentiful porous structures and large specific surface areas. Based on this, designed and constructed are highly dispersed ZnSe nanoparticles anchored in a N-doped porous carbon rhombic dodecahedron (ZnSe@NDPC) by a sequential high-temperature pyrolysis and selenization method. The specific synthesis process involves a two-step heat treatment of the template-engaged reaction between zinc-based zeolitic imidazolate framework (ZIF-8) and selenium power. By optimizing the calcination temperature, the as-synthesized ZnSe@NDPC-700 as an advanced anode of potassium ion batteries demonstrates the best electrochemical performance, including a high capacity (262.8 mA h g(-1) over 200 cycles at 100 mA g(-1)) and a good rate capability (109.4 mA h g(-1) at 2000 mA g(-1) and 52.8 mA h g(-1) at 5000 mA g(-1)). Moreover, the capacitance and diffusion mechanisms are also investigated by the qualitative and quantitate analysis, finally accounting for the superior K storage.