Constructing a robust artificial solid electrolyte interphase with a metal–organic framework for a stable Li metal anode

Abstract

The utilization of Li metal anodes (LMAs) can satisfy the requirements of high-energy-density rechargeable batteries. However, LMAs are plagued by dendrite formation, low coulombic efficiency (CE), and interfacial side reactions. Here, a metal–organic framework (MOF) with high specific area and 1D aligned molecular channels is designed and prepared as an artificial solid electrolyte interphase (SEI) to regulate the interfacial stability of LMAs. The porous structure enables the accommodation of the liquid electrolyte, while the Li⁺ transport channel promotes uniform lithium deposition and mitigates dendrite growth. The open metal sites in the MOF facilitate the entrapment of anions, thereby impeding anion migration and improving Li⁺ transport kinetics. Owing to these advantages, cells based on MOF modified copper current collectors exhibit a high CE of 98.6% for 200 cycles at 1 mA cm⁻² and 1 mA h cm⁻². The symmetric cell shows an improved lifespan of 2000 h with a small voltage hysteresis of 25 mV at 0.5 mA cm⁻² and 1 mA h cm⁻².