Heterogeneous seeds boosting the self-lithiophilic host with dual-phase lithium storage for a stable lithium-metal anode†

Abstract

Lithium (Li)-metal anode holds great promise for high-energy-density battery applications. However, the issue of uncontrollable Li dendrite growth, which is associated with large volume expansion during cycling, remains a significant hurdle. It is well known that the uniform Li⁺ flux, rich lithiophilic nucleation sites, and low local current density are of significant importance for inducing even Li deposition. Herein, a three-dimensional (3D) composite host was constructed by decorating an ultrafine Pt-nanoparticle layer on a carbon fiber framework (CF@Pt) via sputtering. CF with a high graphitic degree was in situ transformed into a lithiophilic LiC₆ phase upon charging, endowing self-lithiophilicity with a low Li nucleation energy barrier. A reversible “dual-phase” Li storage behavior (lithiation and metallization) was spontaneously realized in this 3D host with low local current density. Highly dispersed Pt heterogeneous nano-seeds further served as the lithiophilicity and Li nucleation boosters, consequently leading to even Li⁺ flux distribution and boosting the dense and smooth Li nucleation/growth. Additionally, the as-obtained CF@Pt host shows remarkably improved electrochemical performances in half-cells, symmetrical cells and full-cells.