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

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.