A Supramolecular Electrolyte for Lithium-Metal Batteries

Lithium-metal batteries are regarded as one of the most promising energy storage systems, but they suffer from safety and stability problems owing to unstable liquid electrolytes. To solidify the electrolyte is an effective strategy to promote the strength and stability of the electrolyte-electrode interfaces. However, solidified electrolytes are commonly inferior in bulk and interfacial ion conductivity, rendering unsatisfactory battery performances. Herein, a novel supramolecular electrolyte with high bulk and interfacial ion conductivity is proposed for Li-metal batteries. Supramolecular interactions with oriented assembly and moderate bonding energies endow the lithium-ion transport with low resistance. Additional advantages of flexibility and plasticity improve the interfacial properties. Consequently, the prototype supramolecular electrolyte affords a promising bulk lithium-ion conductivity of 2.9×10⁻⁴ S cm⁻¹, comparable interfacial resistance of 60 Ω, and a low polarity of 152 mV at 0.2 C in LiFePO₄ half-cells at room temperature (25 °C). The supramolecular electrolyte provides not only a new family of electrolyte, but also an effective strategy to promote ion transportation and reduce the interfacial resistance of lithium-based energy storage systems.