Electrochemically Preplated Lithium on Silver Nanoparticle-Decorated Three-Dimensional Vertically Aligned Graphene Foam for Rechargeable Lithium Batteries

Abstract

Graphene-based materials, which exhibit large surface areas and superior electrical properties, are promising materials as anodes in lithium-ion batteries (LIBs). However, the formation of a solid electrolyte interphase (SEI) on the large surfaces of these electrodes causes the loss of active lithium, leading to a severe reduction in coulombic efficiency and cycle retention. In this study, we combined an electrochemical lithium deposition (ELD) strategy, wherein active lithium was inserted into an electrode to minimize lithium loss during cycling, with the use of a vertically aligned three-dimensional (3D) graphene foam. This foam, which was created via freeze-casting, facilitated uniform lithium distribution during ELD, enhancing active lithium utilization. Consequently, the lithium preplated vertically aligned graphene foam anode could improve charge transfer and stabilize the SEI. It exhibited a superior cycle retention of 86% at a current density of 0.5 C for 200 cycles in LIBs, which is superior to that of preplated film-type anodes and lithium foils. Moreover, it enabled the easy infiltration of polymer electrolyte through aligned graphene sheets while maintaining its original cell performance with a liquid electrolyte. Furthermore, it exhibited a higher discharge capacity than that of lithium foil anodes with the same negative/positive ratio in high-areal-capacity lithium–sulfur batteries. Therefore, this paper indicates the potential of preplated vertically aligned graphene foam as a high safety, high-areal-capacity anode for various next-generation rechargeable lithium batteries.