A hybrid energy storage mechanism of carbonous anodes harvesting superior rate capability and long cycle life for sodium/potassium storage

Abstract

Engineering of carbonous materials with excellent electrochemical performances for both sodium and potassium ion batteries is still challenging. In this work, N-doped interconnected carbon spheres with ultrathin nanosheets and expanded interplanar spacing (UNCns) were fabricated by a simple and scalable template-assisted spray pyrolysis method. The hybrid ion storage mechanism endows the UNCns with excellent rate performance and ultra-long cycling lifespan. Moreover, it has been found that the difference between sodium and potassium storage mechanisms in the UNCns strongly influences their performance, which is inspiring to further improve the electrochemical performance of electrode materials by coordinating adsorption (capacitive-controlled) energy storage and redox (diffusion-controlled) energy storage through controlling structural construction.