Ice-Templated\nFree-Standing Reduced Graphene Oxide\nfor Dendrite-Free Lithium Metal Batteries

Abstract

The\nLi metal is increasingly receiving attention as the ultimate\nanode material for Li metal batteries on account of its superior capacity\nand low redox potential. Recent studies have suggested that designing\nnanostructured hosts is an effective approach for resolving chronic\nissues of Li metal anodes, such as dendrite growth and dead Li generation.\nNevertheless, the scalability of the nanostructured materials has\nbeen insufficiently recognized and discussed. Herein, we demonstrate\na facile and scalable synthesis of free-standing reduced graphene\noxide, utilizing the ice-templating method, and its application as\na deposition host for the metallic Li. The synthesized graphene framework\nfeatures a microchannel structure, which is propitious for accommodating\nlarge amounts of Li metal and stabilizing the solid electrolyte interphase\nlayer. We fabricated the ice-templated graphene into a Li metal pouch\ncell and demonstrated an excellent coulombic efficiency of 97% for\n200 cycles and a superior cycle life up to 980 h. Additionally, the\nLi–S full-cell delivered a high areal capacity of 8.5 mAh cm^–2. Our results highlight that the microchannel graphene-based\narchitecture is critical for minimizing the unrestricted growth of\nLi dendrites and alleviating the large volume changes. Furthermore,\nthe scalable synthetic method provides an opportunity for employing\nLi metal at a practical level.