A 3D interconnected metal-organic framework-derived solid-state electrolyte for dendrite-free lithium metal battery

Abstract

The urgent need for high-energy and high-safety batteries is leading research to all-solid-state lithium-metal batteries. However, achieving high ionic conductivities, homogenous Li+ flux, excellent interfacial compatibility, as well as enhanced mechanical strength simultaneously still remain a serious challenge for solid-state electrolyte (SSE). Herein, we rationally develop a three-dimensional (3D) interconnected metal-organic framework (MOF) network-based SSE without any liquid, where the MOF with optimized pore size and strong cationic site is able to restrict anions transport to afford a homogeneous Li+ flux and a high Li+ transference number (0.52). Furthermore, the 3D interconnected MOF-based networks not only build continuous ion conductive pathways for fast Li+ transport (ionic conductivity of 2.89 × 10−4 S cm−1), but also provide structural reinforcement to enhance the mechanical strength (Young's modulus of 819.4 MPa). Consequently, the Li||Li symmetric cell using 3D interconnected MOF-derived SSE can be stably operated for more than 700 h. The all-solid-state lithium-metal full cells fabricated with 3D interconnected MOF-derived SSE exhibit excellent cycling performance even with a 20 µm thin Li anode or high-voltage cathode.