Density functional theory calculations are used to determine the Li, Na, and K storage capacity of a novel 2D graphitic carbon-nitride membrane, C9N4. Three types of pores are present in C9N4 which are regarded as the favorite sites to adsorb metal atoms. According to the results, this graphene-like porous membrane may be an innovative anode material with a substantial storage capacity of 642 mAh.g-1. Furthermore, this theoretical investigation reveals that Li can easily diffuse between bulk C9N4 layers with an energy barrier of 0.16 eV.
