Three-dimensional porous phosphorus-graphdiyne as a universal anode material for both K- and Ca-ion batteries with high performance

Abstract

Motivated by the recent synthesis of 2D boron-graphdiyne and P-doped graphdiyne, for the first time we report a 3D porous phosphorus-graphdiyne (termed 3D-PGDY) with an ultra-low mass density of 0.48 g cm−3, which is stable thermally and dynamically. Moreover, the unique bonding environment of sp-hybridizing provide multiple adsorption sites for K and Ca ions, and the uniformly distributed pores provide the channel for ion transport, exhibiting ultrahigh specific capacity of 1064.56 (2129.12 mAhg−1), low diffusion barriers of 0.1 (0.35 eV), the low open-circuit voltage of 0.27 (0.35 V), and small volume expansion of 2.43 (2.32%) for K (Ca) ion. These outstanding properties demonstrate that assembling graphdiyne into 3D porous structures is very promising for developing novel battery materials.