A DFT study on the potential application of pristine, B and N doped carbon nanocones in potassium-ion batteries.

Although lithium-ion batteries are broadly applied for various purposes, they suffer from safety problems, high cost, and short life. Due to widespread availability, low cost, and nontoxicity of potassium, potassium ion batteries (PIBs) can be applied instead of lithium-ion batteries. Here, dispersion-corrected B3LYP calculations were used to explore potential application of pristine carbon nanocone (CNC) as well as its B- and N-doped models in PIBs. The K cation and K atom were adsorbed onto the center of the apex ring of CNC, and the energies of adsorption were - 19.3 and - 9.0 kcal/mol. The CNC creates a cell voltage of 0.44 V as an anode material which is very small. We showed that substituting some C atoms of CNC by the electron-rich N atoms makes the nanocone more appropriate for application in the PIBs, while B-doping meaningfully decreases the cell voltage. The cell voltage created by the considered nanocones in the PIBs has the following order: N-CNC (~ 1.24 V) > CNC (~ 0.45 V) > > B-CNC (~ 0.24 V). This work illustrated that the N-CNC may be a promising electrode material for PIBs.