Conductive Metal–Organic Frameworks for Rechargeable LiOH-Based Li–O2 Batteries

Abstract

The discharge product Li₂O₂ in conventional Li–O₂ batteries (LOBs) is highly reactive to trigger side reactions and deteriorate the battery performance; these can be circumvented to a great extent in a LiOH-based lithium–oxygen battery, which, however, suffers from efficient catalysis of LiOH formation and decomposition. Herein, we report the first introduction of conductive metal–organic frameworks [conductive MOFs (cMOFs)] to catalyze the LiOH chemistry in LOBs. Specifically, we synthesized three cMOF materials based on M–HHTP (monometallic Ni–HHTP, Co–HHTP, and bimetallic NiCo–HHTP, with HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene). Among them, the bimetallic NiCo–HHTP, benefiting from the synergistic effect of two metal elements, exhibits the best performance in catalyzing the LiOH chemistry of LOBs. It delivers a high discharge capacity (17,845.9 mA h g^–1 at a current density of 100 mA g^–1), excellent rate capability (6445.9 mA h g^–1 at 500 mA g^–1), reduced overpotential and side reactions, as well as high cycle stability, demonstrating great potential to promote the development of high-performance LiOH-based LOBs.