Integration of Metal-Organic Frameworks into a 3D Interconnected Network for Improved Ion Transport

Abstract

Metal-organic frameworks (MOFs) have attracted intensive study as solid electrolytes (SEs) in recent years, especially on facilitating ion transport with functionalized channels. However, MOF particles work separately in SEs and numerous interfaces hinder the high-efficiency ion transport, which lowers the performance of solid-state batteries (SSBs) especially at high C-rate. Herein, we constructed continuous ion pathways by integration of MOFs into a 3D interconnected network. Particle arrays of a newly developed MOF (Zr-BPDC-2SO3H) which has single ion transport ability were grown on the bacterial cellulose (BC) nanofibers to provide a linear ion transport network. The interconnected MOFs network exhibits higher ionic conductivity of 7.88 × 10− 4 S cm− 1 at 25 ℃, single ion transport ability (ʈLi+=0.88), wide electrochemical window up to 5.15 V, excellent interface compatibility and capability for supressing lithium dendrites. Most importantly, the SSB fabricated with the interconnected MOFs network shows more than 100% improved specific capacity than the SSB without integration and stable cycling performance at 3 C. This work demonstrates the effectiveness of integrated design and paves new way for developing high-performance SEs based on porous ion conductors.