  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, for the purpose of the high reliability and safety in their
applications. Here, we investigated the mechanical properties of both bulk and
single layer phosphorus during the lithium intercalation process by using the
first-principles calculations. Our results show that the Young's modulus of
bulk and 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 layer phosphorus, which may reduce the reliability of Li-ion
batteries. Our findings suggest that this remarkable mechanical properties
deterioration during Li intercalation should be considered carefully in the
mechanical design of Li-ion batteries, in order to keep they working reliably
and safely in the charge-discharge process.
