R-graphyne monolayers as anodic material for future K-ion batteries: A DFT study

In the search for sustainable energy options, finding new, affordable, and reliable anode materials for potassium-ion batteries (KIBs) has become a crucial focus of research. Present research paper presents a potential K anode material in the form of a two-dimensional R-graphyne (R-gyn) monolayer, investigated using first-principles calculations. Stability of R-gyn has been verified through molecular dynamics (MD) simulations, examining both its structure and thermodynamics. Furthermore, an analysis of its electronic structure reveals that the R-gyn monolayer exhibits semi metallic features. Particularly noteworthy is the exceptionally high theoretical specific capacity (TSC) for potassium ions shown by R-gyn, which can reach up to 476.32 mAhg⁻¹. The significant capacity is paired with relatively minor diffusion barriers (95 meV) and advantageous open-circuit voltages (OCVs) ranging between 1.61–0.29 V. These attributes of the suggested R-gyn material suggest its capability to enable high-capacity energy storage and enhance swift ionic diffusion within potassium-ion batteries.