Coupling of triporosity and strong Au–Li interaction to enable dendrite-free lithium plating/stripping for long-life lithium metal anodes

Abstract

The construction of a lithiophilic phase on the surface of a current collector with a lithiophobic nature is an effective method to suppress Li dendrite growth by reducing the overpotential for Li nucleation and inducing the growth of homogeneous Li nuclei to obtain high-performance lithium metal anodes (LMAs). Nevertheless, the structural regulation of the lithiophilic phase and the underlying mechanism of lithiophilicity have been overlooked in previous studies. In this study, we designed a triporous, nanoporous AuLi₃ (NPAuLi₃) nanosheet-modified Ni foam (NF) (NPAuLi₃@NF) composite current collector for use in LMAs. First principle calculations revealed that the lithiophilicity of the AuLi₃ phase originates from the strong electronic interaction between the Au and Li atoms. The morphological characterization demonstrated that the as-designed NPAuLi₃@NF current collector not only guided homogeneous Li nucleation and growth during the Li plating process, but also induced uniform Li removal during the Li stripping process, which effectively suppressed Li dendrite growth and formation of dead Li, leading to a boosted electrochemical performance in LMAs. The symmetric Li|Li cells with the NPAuLi₃@NF-based LMAs could run stably for 1990 and 1420 h without cell failure at current densities of 1 and 2 mA cm⁻² with a capacity of 2 mA h cm⁻², respectively, and the Li@NPAuLi₃@NF|LFP full cells showed an excellent capacity retention of 83.8% with a coulombic efficiency of 99.8% at 5C after 1000 cycles, and a good rate capability. This work provides insight into the design of the composition and structure of the lithiophilic phase on the surface of the current collector skeleton to obtain high-performance LMAs.