Layer-by-Layer Assembly of Graphene Oxide and Silver Nanowire Thin Films with Interdigitated Nanostructure in Dendrite Suppressions of Li-Metal Batteries

Abstract

Reducing the thickness of the Li-metal anode is key to enhancing the energy density of batteries. However, poor initial lithium deposition on Cu current collectors can exacerbate the growth of lithium dendrites and limit performance. This study explores innovative strategies by fabricating graphene oxide (GO) and silver nanowire (AgNW) thin films onto Cu-foil using the layer-by-layer (LbL) assembly method. The homogeneous LbL thin films are prepared with the assistance of bifunctional cross-linkers, such as cysteamine, to strengthen the intermolecular interactions between the nano-building blocks. The GO/AgNW LbL thin films possess a highly interdigitated nanostructure that combines the synergistic advantages of the individual building components. The GO layers facilitate the distribution of Li-ionic flux through the films, which promotes the formation of stable solid electrolyte interphase layers. In addition, the AgNW layers provide electrical pathways and serve as nucleation sites for Li & horbar;Ag alloy reactions. These combined effects lead to a flat and stable initial Li-deposition, as well as dense and compact Li growth, without significant dendrite formation. The full cell tests show excellent cycle longevity, 430 cycles with an N/P ratio of 3.36 at 1 C and 250 cycles with an N/P ratio of 1.81 at 3 C.