Building an In-rich interphase to stabilize lithium metal anodes with a solid-like electrolyte†

Abstract

Lithium metal is an ideal candidate for the anode material of high-energy-density batteries due to its high theoretical specific capacity and low electrochemical potential. However, dendrite growth and poor reversibility prevent its practical applications. To address these issues of Li metal anodes in conventional liquid electrolytes, we developed a solid-like electrolyte (SLE) leveraging a metal–organic framework (MOF) with chelated indium ions on its ligands. The SLE exhibits an excellent ionic conductivity of 1.39 S cm⁻¹ at 30 °C and a Li ion transference number of 0.46, enabling efficient Li ion transport. The ordered microtunnels within the SLE promote uniform Li deposition, effectively suppressing dendrite formation. Notably, the SLE induces the formation of an indium-rich interphase on Li metal anodes during cycling, which reduces the energy barrier for interfacial Li ion diffusion and enhances anode reversibility. As a result, Li symmetric cells with the SLE achieve stable plating and stripping for over 1200 hours and support a high critical current density of 2.0 mA cm⁻². Benefiting from these advantages, the solid-like LiFePO₄ cells demonstrate exceptional room-temperature performance, delivering a reversible capacity of 78 mA h g⁻¹ at an ultra-high rate of 10 C and maintaining stable cycling for over one year at 0.1 C without short-circuit.