Design of thiol–lithium ion interaction in metal–organic framework for high-performance quasi-solid lithium metal batteries

Abstract

Metal–organic frameworks (MOFs) have recently emerged as promising solid electrolytes (SEs) for solid-state batteries (SSBs). Developing MOFs with high-density functional groups may improve the spatial density of hopping sites and facilitate ion transport. Herein we synthesized a new series of ion conductive MOFs, Zr–MA–M (M = Li⁺, Na⁺, K⁺, Zn²⁺), with high density –SH groups functionalized in small pores and metal ions adsorbed on the thiol groups. Taking advantage of the interaction between S and metal ions, such ion conductors show high ionic conductivity, low interfacial resistance, high lithium ion (Li⁺) transference number (0.63) and wide electrochemical window up (4.6 V). Moreover, the SSBs assembled with Zr–MA–Li⁺ based SE exhibit excellent rate performance (106 mA h g⁻¹ at 2C) and remarkable cyclic stability (low decay rate of 0.21‰ per cycle for 700 cycles at 2C). Thus, this study provides a new route for developing high-performance MOF-based SEs via the application of host–guest interaction.