Catechol-Type Porphyrin-Based Bimetallic MOF for High-Capacity Lithium-Ion Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal-organic frameworks (MOFs) show promise for energy storage due to their unique structures.
• Existing MOFs often suffer from poor kinetics and stability as lithium-ion battery anodes, leading to capacity loss.

Purpose of the Study:

• To design and synthesize novel bimetallic MOFs using a metalloporphyrin ligand for enhanced lithium storage.
• To investigate the electrochemical performance and lithium storage mechanisms of the synthesized MOFs.

Main Methods:

• Synthesis of a metalloporphyrin-based ligand and two bimetallic MOFs (CMF and CMC).
• Electrochemical characterization including cycling performance, rate capability, and stability tests.
• Theoretical calculations and material characterization to understand performance.

Main Results:

• CMF exhibited superior electrochemical performance compared to CMC.
• CMF achieved an ultrahigh specific capacity of 988 mAh g^-1 after 150 cycles at 100 mA g^-1.
• CMF demonstrated excellent rate performance and long-term cycling stability, retaining 482.5 mAh g^-1 after 800 cycles at 2500 mA g^-1.

Conclusions:

• The designed metalloporphyrin-based MOFs, particularly CMF, offer significant improvements for lithium-ion battery anodes.
• The study elucidates the reasons behind CMF's excellent performance and its lithium storage mechanism.