Superlithiophilic graphene-silver enabling ultra-stable hosts for lithium metal anodes

Abstract

Lithium (Li) metal anodes are considered to be one of the most superior anodes due to their high energy density and lowest electrochemical potential. However, the formation of Li dendrites, uneven deposition, and infinite relative dimension change hinder their popularity. In this work, three-dimensional (3D) graphene composite silver nanoparticles (GO-Ag NPs) were proposed as the Li hosts. The graphene–silver–lithium (GAL) composite anode prepared via the thermal infusion strategy of Li ions effectively inhibits the formation of Li dendrites and the infinite relative dimension change to achieve long-term cycling stability. The modified lithiophilic nature of the GAL composite anode was achieved through the decoration of silver nanoparticles, effectively reducing the nucleation barrier of Li ions and inducing their uniform deposition. Also, the conductive porous 3D graphene aerogel is more conducive to the transport of Li ions/electrons, while providing sufficient space for Li deposition, thereby avoiding the volume change of Li anodes. Therefore, in the evaluation of symmetrical cells, the GAL composite anode exhibit a flat voltage profile and long-term cycling stability, and can be operated at a high current density of 3 mA cm⁻² over 400 cycles. Similarly, when matching the full cells with LiFePO₄ (LFP) or Li₄Ti₅O₁₂ (LTO), the capacity retention of the LFP/GAL full cell could reach up to 96% after 300 cycles in comparison with 81% of the bare Li anode, enabling the long-term operation of the LTO/GAL full cell over 450 cycles.