Li+ Ion-Dipole Interaction-Enabled a Dynamic Supramolecular Elastomer Interface Layer for Dendrite-Free Lithium Metal Anodes

Abstract

The unstable lithium (Li)/electrolyte interface, causing inferior cycling efficiency and unrestrained dendrite growth, has severely hampered the practical deployment of Li metal batteries (LMBs), particularly in carbonate electrolytes. Herein, we present a robust approach capitalizing on a dynamic supramolecular elastomer (DSE) interface layer, which is capable of being reduced with Li metal to spontaneously form strong Li⁺ ion-dipole interaction, thereby enhancing interfacial stability in carbonate electrolytes. The soft phase in the DSE structure enables fast Li⁺ transport via loosely coordinated Li⁺-O interaction, while the hard phase, rich in electronegative lithiophilic sites, drives the generation of fast-ion-conducting solid electrolyte interface components, including Li₃N and Li₂S. Furthermore, the dynamically resilient DSE network composed of soft and hard phases protects Li anodes from electrolyte corrosion and accommodates volume changes during cycling. All features of the DSE layer synergistically facilitate uniform Li⁺ deposition and suppress Li dendrite propagation, ensuring a stable and dendrite-free Li anode. Consequently, the symmetric Li||Li cell incorporating the DSE layer achieves cycling stability exceeding 6000 h under 1 mA cm^-2 and 1 mA h cm^-2 conditions. Furthermore, full cell pairing DSE/Li anode with LiFePO₄ (LFP) or high-voltage LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathodes exhibits high-efficiency Li deposition and cycling stability, even under constrained conditions of limited Li (40 μm) and ultrahigh loading NMC811 cathode (21.5 mg cm^-2). This study underscores the effectiveness of the ion-dipole interaction-enabled DSE network in developing stable, high-energy-density LMBs.