  The prospects of phosphorene as an anode material for high performance Li-ion
battery was systematically investigated from the first principle calculations
and experimental measurements. The diffusion energy barriers of a Li atom
moving along various orientations on phosphorene layer were calculated from the
Li adsorption energy landscape. It was found that the diffusion mobility of a
Li atom along the zigzag direction in the valley of phosphorene could be about
7 to 11 orders of magnitude faster than that along the other directions,
indicating its ultrafast and anisotropic diffusivity. The lithium insertion in
phosphorene was studied considering various LinP16 configurations (n=1~16). It
was found that phosphorene could accommodate up to one Li per P atom (i.e.,
Li16P16), and the predicted theoretical value of the Li capacity for a single
layered phosphorene can reach about 865 mAh/g. Our experimental measurement on
the Li capacity for a network of a few layered phosphorene can reach a
reversible stable value of ~ 453 mAh/g even after 50 cycles. In particular, it
was found that, even at the high Li concentration (e.g., x = 1 in LixP), there
was no Li clustering and the structure of phosphorene is reversible during the
lithium intercalation. Our results clearly show that phosphorene has promise as
a novel anode material for high performance Li-ion batteries.
