Lithium intercalation drives mechanical properties deterioration in bulk and single-layered black phosphorus: A first-principles study

It is of critical importance to understand the mechanical properties change of electrode materials during lithium intercalation in the mechanical design of Li-ion batteries (LIBs), for the purpose of the high reliability and safety in their applications. Here, we investigated the mechanical properties of both bulk and single-layered black phosphorus (BP) during the lithium intercalation process by using the first-principles calculations. Our results show that the Young's modulus of bulk and single-layered phosphorus strongly depends on the lithium intercalation. The mechanical bearing capacities, such as critical strain and stress, are significantly reduced by several times after lithium intercalation in both bulk and single-layered BP, which may reduce the reliability of LIBs. Our findings suggest that this notable mechanical properties deterioration during lithium intercalation should be considered carefully in the mechanical design of LIBs, in order to keep the work reliable and safe in the charge-discharge process.