A Two-dimensional Metal-Organic Framework as Promising Cathode for Advanced Lithium Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Anthraquinone derivatives show promise as electrode materials for lithium-ion batteries (LIBs) due to their high theoretical capacity and abundance.
• A major challenge is the dissolution of anthraquinone active materials in organic electrolytes, leading to rapid capacity fade during cycling.

Purpose of the Study:

• To develop a stable anthraquinone-based electrode material for LIBs by preventing active material dissolution.
• To enhance the electrochemical performance and cycle stability of anthraquinone electrode materials.

Main Methods:

• Fabrication of a two-dimensional calcium anthraquinone 2,3-dicarboxy metal-organic framework (2D CaAQDC MOF) using a simple hydrothermal method.
• Electrochemical testing of the 2D CaAQDC MOF as a cathode material in LIBs, evaluating specific capacity, cycle stability, and performance at various current densities.

Main Results:

• The 2D CaAQDC MOF effectively inhibited the dissolution of anthraquinone into the electrolyte, promoting lithium-ion diffusion.
• The CaAQDC electrode exhibited a specific capacity of ~100 mAh/g at 50 mA/g after 200 cycles, demonstrating good cycle stability.
• A specific capacity of ~60 mAh/g was achieved at a high current density of 200 mA/g.

Conclusions:

• The 2D coordination polymer structure of CaAQDC MOF successfully restrained anthraquinone dissolution and enhanced structural stability.
• This molecular design strategy significantly improved the electrochemical performance of anthraquinone for LIB applications.
• The findings offer a viable approach for designing stable organic electrode materials for next-generation energy storage devices.