Ultrastable Organic Anode Enabled by Electrochemically Active MXene Binder toward Advanced Potassium Ion Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Conjugated carbonyl compounds show promise as organic anode materials for potassium ion batteries (PIBs).
• However, their low electrical conductivity and solubility in electrolytes limit practical applications.
• Developing effective binders is crucial for enhancing their performance.

Purpose of the Study:

• To utilize 2D MXene as an electrochemically active binder for perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) electrodes in PIBs.
• To improve the electrochemical performance and stability of organic anodes.
• To overcome the limitations of low conductivity and solubility in PTCDA-based anodes.

Main Methods:

• Fabrication of PTCDA electrodes using MXene and Super-P particles as a binder and conductive matrix.
• Electrochemical characterization of the PTCDA electrode in PIBs.
• Assembly and testing of an all-PTCDA potassium ion full cell.

Main Results:

• The MXene/Super-P system effectively restrained PTCDA solubility and alleviated volume expansion.
• The PTCDA electrode achieved a high capacity of 462 mAh g^-1 at 50 mA g^-1 and excellent rate capability (116.3 mAh g^-1 at 2000 mA g^-1).
• Stable cycling performance exceeding 3000 cycles with minimal capacity decay (∼0.0033% per cycle) was observed.
• An all-PTCDA full cell demonstrated a maximum energy density of 179.5 Wh kg^-1.

Conclusions:

• MXene serves as a superior electrochemically active binder for organic anodes in PIBs.
• The MXene/Super-P system significantly enhances ion and electron transport, potassium adsorption, and electrode stability.
• This approach promotes the practical application of organic anode materials for high-performance potassium ion batteries.