Current-Density Regulating Lithium Metal Directional Deposition for Long Cycle-Life Li Metal Batteries.

Uncontrolled dendrite formation in the high energy density of lithium (Li) metal batteries (LMBs) may pose serious safety risks. While numerous studies have attempted to protect separators, these proposed methods fail to effectively inhibit upward dendrite growth that punctures through the separator. Here, we introduce a novel 'orientated-growth' strategy that transfers the main depositional interface to the anode/current collector interface from the anode/separator interface. We placed a layer of cellulose/graphene carbon composite aerogel (CCA) between the current collector and the anode (LCL-bottom). This layer works as a charge organizer; it induces a higher apparent current density and encourages Li to deposit at the anode/current collector interface. Both in situ and ex situ images of the electrode demonstrate that the anode part of the cell has been flipped; with the newly deposited particles facing the current collector and the smooth surface facing the separator. Electrochemical characterization of the electrode in half and full cells showed outstanding cyclic stability and rate capability, with the LCL-bottom/LPF full cell capable of maintaining 94% of its initial capacity after 1000 cycles. We believe that this innovative strategy will leapfrog the barriers of LMBs development.