Theoretical Investigation of Cyanographene and Cyanographite for Potential Sodium‐Ion Battery

Sodium‐ion batteries (SIBs) draw much attention as alternative charge carrier to lithium because of their abundance and cost‐effectiveness. However, SIBs are limited by their low capacity to achieve comparable loadings in graphite. Herein, cyanographene and cyanographite are proposed as materials exhibiting superior storage capacity, facilitating sodium ionization. First‐principle calculations are performed to evaluate the sodium adsorption and diffusion of cyanographene and cyanographite. In the calculation, it is shown that sodium atoms diffuse with relatively low activation energy over cyanographene and cyanographite. It is found out that cyanographene and cyanographite have greater sodium‐storage capacity than graphite. The high sodium mobility and large sodium‐storage capacity demonstrate that cyanographene and cyanographite are a promising anode material for SIBs.