Three-Dimensional Graphene/Ag Aerogel for Durable and Stable Li Metal Anodes in Carbonate-Based Electrolytes.

Abstract

The use of Li metal as the anode for Li-based batteries has attracted considerable attention due to its ultrahigh energy density. However, the formation of Li dendrites, uneven deposition, and huge volume changes hinder its reliable implementation. These issues become much more severe in commercial carbonate-based electrolytes than in ether-based electrolytes. Herein, a rationally designed three-dimensional graphene/Ag aerogel (3D G-Ag aerogel) is proposed for Li metal anodes with long cycle life in carbonate-based electrolytes. The modified lithiophilic nature of G-Ag aerogel, realized through decoration with Ag NPs, effectively decreases the energy barrier for Li nucleation, regulating uniform Li deposition behavior. Moreover, the highly flexible, conductive 3D porous architecture with hierarchical mesopores and macropores can readily accommodate deposited Li and ensures the integrity of the conductive network during cycling. Consequently, high coulombic efficiency (over 93.5 %) and a significantly long cycle life (1589 h) over 200 cycles, with a relatively high cycling capacity of 2.0 mAh cm-2 , can easily be achieved, even in a carbonate-based electrolyte. Considering the intrinsic high voltage windows of carbonate-based electrolytes, matching the G-Ag aerogel Li metal anode with a high-voltage cathode can be envisaged for the fabrication of high-energy-density Li secondary batteries.