Stable Li metal anode in a lithiophilic shuttle

Abstract

Suppressing severe lithium (Li) dendrite growth is a formidable challenge for high-energy-density lithium (Li) metal batteries (LMBs). Conventional lithiophilic coatings, despite their ability to improve the Li plating morphology, generate a compact conversion layer with a low electrolyte volume fraction, impeding the mass- and charge-transfers at the electrode interface and offsetting the benefits brought by lithiophilicity. Herein, a lithiophilic shuttle is obtained by the superposition of very thin layered copper oxide (L-CuO) flakes. After the conversion process, conjoined channels with a high electrolyte volume fraction can be maintained in the lithiophilic shuttle for fast and lateral Li⁺ transfer. In addition to the inherent high-Li-affinity and layered-structure-induced capacitive feature, the lithiophilic shuttle can afford stable and reversible Li plating/stripping at high current densities up to 3 mA cm⁻² in LMBs with a practical capacity of 5 mA h cm⁻². This work provides a new hierarchical lithiophilic structure to push forward high-energy-density LMBs for practical applications.