Towards 3D-lithium ion microbatteries based on silicon/graphite blend anodes using a dispenser printing technique

Area of Science:

• Materials Science
• Electrochemistry
• Additive Manufacturing

Background:

• 3D-printed lithium-ion microbatteries (3D-MLIBs) offer potential for compact energy storage.
• Developing high-performance slurries is crucial for advanced 3D-MLIB fabrication.
• Understanding the interplay between slurry properties and printing behavior is essential.

Purpose of the Study:

• To investigate silicon/carbon-graphite slurries for 3D-MLIBs.
• To correlate electrochemical and rheological properties of anode slurries.
• To optimize binder content for automated dispensing and performance.

Main Methods:

• Systematic variation of binder content (CMC/SBR) in anode slurries.
• Rheological analysis to assess viscosity and yield stress.
• Electrochemical testing of printed micro anode structures in coin cells.

Main Results:

• Increased binder content enhanced slurry viscosity and yield stress, enabling higher aspect ratio structures.
• 6-layer structures with aspect ratios up to 6.5 were achieved using 24 wt% binder.
• Anodes with 12 wt% binder showed highest capacity (484 mA h g⁻¹) and excellent rate capability (89% retention at 4C).

Conclusions:

• Binder content significantly impacts both printability and electrochemical performance of 3D-MLIB anode slurries.
• 18 wt% CMC/SBR offers a promising balance for future 3D-MLIB development.
• This research provides a foundation for automated production of high-performance 3D-MLIBs.