Micron Size NaCrO₂ Particles Enable High-loading Dry-processed Electrode for Sodium Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Dry-process fabrication offers cost-effective and eco-friendly electrode production for energy storage.
• Understanding active material particle size effects is crucial for optimizing dry electrodes.

Purpose of the Study:

• To investigate how varying particle sizes of NaCrO2 impact the performance of dry-processed, high-loading electrodes.
• To identify optimal particle characteristics for enhanced electrode properties.

Main Methods:

• Synthesis of NaCrO2 with four distinct particle sizes (0.6 µm to 9.9 µm).
• Fabrication of high-loading electrodes using a dry process.
• Evaluation of mechanical strength (tensile strength) and electrochemical performance (cycling stability, rate capability).

Main Results:

• Larger micron-sized NaCrO2 particles (>4.4 µm) significantly enhance tensile strength and electrochemical performance.
• Improved properties are attributed to reduced porosity, better binder-particle connections, and enhanced conductivity.
• A full cell with a high-loading electrode (5.2 mAh cm⁻² , 96.5 wt.% active material) showed excellent cycling stability and rate capability.

Conclusions:

• Particle size is a critical parameter for designing high-performance dry-processed electrodes.
• Micron-sized NaCrO2 particles are advantageous for achieving superior mechanical integrity and electrochemical efficiency.
• This research provides foundational insights for fabricating advanced energy storage electrodes via dry processing.