In-situ Li+ insertion induced lithiophilic expansion graphite for dendrite-free lithium metal anode

For the most ordinary graphite negative electrode, the inserted Li+ occupies interlamellar spacing in the graphite lattice, and transform into Li-graphite phase (LiXC6). During the high charging rates, Li+ is adsorbed preferentially on lithiated LiXC6 which promotes Li crystallization and grows into uncontrollable dendrites. Thus, how to apply this defect to advantage and extend into stabilizing Li metal plating is ignored in practice. Herein, expansion graphite (EG) is ornamented as lithiophilic porous carbon basement which leverages insertion Li+ as inducing sites. In this way, Li metal grows preferentially on the lithiated graphite layer and ensuring the plating/stripping stably and suppressing the growth of lithium dendrites. Consequently, a stable polarization of 49.5 mV is obtained with EG anode in a symmetrical cell with 320 h even at a high current density of 10 mA cm(-2) and high areal capacity of 10 mAh cm(-2). Additionally, the resulting EG@Li assembled LFP full cell could deliver 85% capacity retention after 500 cycles.& nbsp;(c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The growth of lithium dendrites on graphite negative electrodes during high charging rates can be suppressed by using expansion graphite as inducing sites, allowing for stable plating and stripping of lithium metal.