Two-dimensional CrP2 with high specific capacity and fast charge rate for lithium-ion battery

Abstract

The electrode material is regarded as one of the key factors that determine the performance of lithium-ion batteries (LIBs). However, it is still a challenge to search for an anode material with large capacity, low diffusion barrier, and good stability. In the present work, two new CrP2 monolayers (Pmmn-CrP2 and Pmma-CrP2) are predicted by means of first principles swarm structure search. Our study shows that both the two CrP2 monolayers have high dynamical and thermal stability, as well as excellent electron conductivity. Additionally, Pmmn-CrP2 exhibits a remarkably high storage capacity of 705 mA⋅h⋅g−1 for Li, meanwhile the diffusion energy barrier of Li on the surface of this monolayer is 0.21 eV, ensuring it as a high-performance anode material for LIBs. We hope that our study will inspire researchers to search for new-type two-dimensional (2D) transition metal phosphides for the electrode materials of LIBs.