Biphenylene and Phagraphene as Lithium Ion Battery Anode Materials.

We present results of density functional theory calculations on the lithium (Li) ion storage capacity of biphenylene (BP) membrane and phagraphene (PhG) which are two-dimensional defected-graphene-like membranes. Both membranes show a larger capacity than graphene, Li2C6 and Li1.5C6 compared to LiC6. We find that Li is very mobile on these materials and does not interact as strongly with the membranes. In the case of BP we also investigated the possible volume expansion on Li insertion. We find a 11% expansion, which is very similar to the one found in graphite. Our findings show that both membranes are suitable materials for lithium ion battery anodes.