Dendrite-free lithium metal batteries achieved with Ce-MOF membrane coating with one-dimensional continuous oxygen-containing channels for rapid migration of Li ions

Abstract

Lithium metal batteries (LMBs) offer the highest theoretical capacity (3860 mA h g⁻¹), but suffer from the issue of formation of lithium dendrites during device operation owing to inhomogeneous growth of lithium. In this work, we demonstrated that using metal–organic frameworks (MOFs) with tailored one-dimensional transport channels and chemical compositions, lithium dendrite-free LMBs can be achieved, leading to LMBs with high rate performance and long cycling life. The MOF is based on cerium (Ce) metal cations (Ce-MOF-1) and possesses 1D transport channels composed of continuous oxygen-containing ligands constructed by [Ce₆(μ₃-O)₄(μ₃-OH)₄(–CO₂)₈] nodes and 2,5-furandicarboxylic acid ligands. It was found that, compared to cage-like frames, the energy barrier for Li ion migration is two times lower with Ce-MOF-1 (0.18 eV). The energy barrier for Li⁺ transport is further reduced in the presence of large anions such as TFSI⁻ in the electrolyte. As a consequence, we achieved a highly-stable Li plating/stripping cycling for over 3000 h at an ultrahigh current density (15 mA cm⁻²) and large stripping-plating capacity (30 mA h cm⁻²). The effectiveness of using Ce-MOF-1 membrane coating in hindering the formation of Li-dendrites and forming a stable Li-metal electrode was further verified in full cells of Li–S and Li–LiFeO₄ cells. These encouraging results have shed light on the design of effective membrane coating by using MOFs with tailored structures and compositions to achieve high-rate lithium metal batteries.