Robust Artificial Solid-Electrolyte Interfaces with Biomimetic Ionic Channels for Dendrite-Free Li Metal Anodes

A robust artificial solid electrolyte interphase (SEI) film with biomimetic ionic channels and high stability is rationally designed and fabricated by combining the ClO4--decorated metal-organic framework (UiO-66-ClO4) and flexible lithiated Nafion binder (Li-Nafion). The high electronegativity and lithiophilicity of ClO4- groups chemically anchored into the UiO-66 channels endow the SEI film with an excellent single-ion conducting pathway, high Li+ transference number, and outstanding ionic conductivity, which can effectively prohibit undesirable reactions of the Li metal with the electrolyte and regulate fast and uniform Li+ flux. With further assistance of the flexible Li-Nafion binder, the resulting UiO-66-ClO4/Li-Nafion (UCLN) composite film exhibits an excellent mechanical strength to suppress the growth of Li dendrites and maintain the integral stability of the Li metal anodes during cycling. Consequently, the UCLN coated Li metal anodes (Li@UCLN) deliver remarkable cycling stabilities even under a high current density of up to 20 mA cm(-2) and large areal capacity of up to 30 mAh cm(-2), as well as enhanced rate capacities and cycle lifespans in the full cells even under the harsh conditions for high-energy density applications.

Automated summary

A robust artificial solid electrolyte interphase (SEI) film with biomimetic ionic channels and high stability is designed and fabricated by combining UiO-66-ClO4 and Li-Nafion. The resulting composite film exhibits excellent single-ion conducting pathway and ionic conductivity to prohibit undesirable reactions of Li metal with the electrolyte, suppress Li dendrite growth, and maintain stability during cycling. Coated Li metal anodes show remarkable cycling stabilities, enhanced rate capacities, and extended cycle lifespans even under high-energy density applications.