Graphene coated lithium foil anode enables long cycle life Li metal pouch cells

Abstract

Among various technologies that go beyond lithium-ion batteries, lithium metal batteries (LMBs) have been intensively studied as the next generation of high-energy battery technology. However, achieving scalable production of dendrite-free lithium metal anodes (LMAs) for practical application is still a formidable challenge. Herein, we propose a simple and feasible method to modify lithium foil with graphene coatings, which is expected to be used in practical applications on a large scale. Graphene has a high specific surface area and excellent electrical conductivity, which can disperse current density, induce uniform Li deposition, and reduce the generation of dendrites and dead lithium. Meanwhile, the porous graphene coating layer is beneficial to the continuous compensation of irreversible active Li loss by the Li foil underneath the graphene coating. As a result, pouch cells using graphene coated Li anode display superior cyclic stability comparing to the cell with bare Li anode. The cell with a high areal capacity of 4 mAh cm−2 reaches a high capacity retention of 76% after 470 charge/discharge cycles at a current density of 0.1C.