Adsorption and diffusion of K in N-doped layered carbon TA-BGY with pores for anode of K ion batteries

Abstract

The exploration of anode materials is important for the development of K-ion batteries (KIBs) as the promising alternative of Li-ion batteries. The large ionic radius of K ions greatly constrains the selection of anode materials. We propose the pores with appropriate size in structure can promote the storage of K ions. In this work, we studied the potential of layered carbon with pores as the anode of KIBs with TA-BGY as structural model by combining the first-principles calculations and molecular dynamical (MD) simulations. It is found that the doped N with lone electron pair can promote the adsorption of K ions at the edge of pore. The theoretical capacity of K can reach 796 mAh/g and the open circuit voltage is just 0.6 V. In addition, this structure has the low diffusion barrier of 0.48 eV and high structural stability under high K loading. We posit that N-doped layered carbon TA-BGY, featuring pores, holds the potential to serve as an exceptional anode material for KIBs.