Trimetallic Metal-Organic Framework Nanoframe Superstructures: A Stress-Buffering Architecture Engineering of Anode Material toward Boosted Lithium Storage Performance

Abstract

Metal-organic frameworks (MOFs) can serve as prevailing anodes for lithium-ion batteries, due to their multiple redox-active sites and prominent structural compatibility. However, the poor electronic conductivity and inferior cyclability hinder their further implementation. Herein, a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture (Fe-Co-Ni NFSs) via structural evolution is proposed for versatile anode materials for lithium storage. Ascribed to optimal compositional and structural optimization, the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity (1030 mAh g−1 at 0.1 A g−1), outstanding rate capacity (414 mAh g−1 at 2 A g−1), and prolonged cyclability (489 mAh g−1 upon 1000 cycles at 1 A g−1). Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity, confer multiple active sites, and energetically favor Li adsorption capability. Additionally, the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization, further improving the lithium storage capability. This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.