LiI/Cu Mixed Conductive Interface via the Mechanical Rolling Approach for Stable Lithium Anodes in the Carbonate Electrolyte

Abstract

The nonuniform ion/charge distribution and slow Li-ion diffusion at the Li metal/electrolyte interface lead to uncontrollable dendrites growth and inferior cycling stability. Herein, a simple mechanical rolling method is introduced to construct a mixed conductive protective layer composed of LiI and Cu on the Li metal surface through the replacement reaction between CuI nanoflake arrays and metallic Li. LiI can promote Li + transportation across the interface, achieving homogeneous Li + flux and suppressing the growth of Li dendrite, while the homogeneously dispersed Cu nanoparticles can offer abundant nucleation sites for Li deposition, resulting in a remarkably homogenized charge distribution. As expected, Li metal with the LiI/Cu protection layer (LiI/Cu@Li) exhibits a significantly prolonged lifespan over 350 h with slight polarization at a deposition capacity of 3 mAh cm −2 in the carbonate electrolyte. Besides, when matched with high mass loading LiFePO 4 cathodes (20 mg cm −2 ), the LiI/Cu@Li anodes exhibit much improved cycle stability and rate performance. Highly scalable preparation processes as well as the impressive electrochemical performances in half cells and full cells indicate the potential application of the LiI/Cu@Li anode.

Ultrathin Composite Li Electrode for High‐Performance Li Metal Batteries: A Review from Synthetic Chemistry

“…Recently, Xiong Group reported an interesting work, where they constructed a mixed electronic and ionic conductive layer on the Li surface by rolling Li metal and self‐supported CuI nanoflake arrays (Figure 10c). [ 50 ] In such an ultrathin composite Li electrode, LiI ensures rapid Li + transfer across the SEI layer and achieves homogeneous Li + flux, suppressing the dendritic growth. The homogeneously dispersed Cu nanoparticles can be used as the nucleation sites to accelerate Li deposition, resulting in a remarkably homogenized charge distribution.…”

“…c) Synthesis diagram of the CuI layer on Cu foils and the formation of the LiI/Cu layer on Li foils. Reproduced with permission [50]. Copyright 2022, American Chemical Society.…”

In Situ Formed LiI Interfacial Layer for All-Solid-State Lithium Batteries with Li6PS5Cl Solid Electrolyte Membranes

“…Lithium iodide (LiI) is a good conductor of Li-ions, and LiI ASSBs that use LiI as an electrolyte have been employed in commercially available pacemakers for a while. , In addition, LiI is chemically stable, environmentally friendly, and highly compatible with both Li metal and solid-state electrolytes. , Herein, a simple in situ solid–gas reaction method has been proposed to prepare a homogeneous LiI layer as a protective layer on the Li metal anode surface. A LiI@Li–SSE–LiI@Li symmetric cell can function stably for 150 h at a current density of 0.1 mA cm –2 at room temperature.…”