Discrete Microdomain-Bonded Binder Enables Mechanically Robust Micron-Silicon Anodes in Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Micron-silicon (µSi) offers high capacity for lithium-ion batteries (LIBs) but suffers from >300% volume expansion during cycling.
• Existing binder strategies focus on continuous networks, which are insufficient for mitigating µSi volume changes.
• Advanced functional binders are critical for overcoming µSi anode limitations.

Purpose of the Study:

• To introduce a novel discrete microdomain bonding (DMB) paradigm for stabilizing µSi anodes.
• To investigate the DMB strategy's ability to accommodate significant volume changes in µSi particles.
• To enhance the mechanical tolerance and cycling lifespan of µSi anodes.

Main Methods:

• Development of a DMB binder system utilizing short-chain molecules for µSi particle anchoring.
• Formation of interfacial hydrogen bonds for microdomain-level particle stabilization.
• Evaluation of electrochemical performance, including capacity, coulombic efficiency, and cycle retention.

Main Results:

• The DMB binder enabled µSi anodes to maintain electrical contact and mechanical integrity during cycling.
• Achieved a high initial coulombic efficiency (ICE) of 92.5%.
• Demonstrated a remarkable capacity of 2517.4 mAh g⁻¹ with 98.2% retention after 100 cycles at 0.5 A g⁻¹.

Conclusions:

• The DMB paradigm effectively addresses the volume expansion challenge in µSi anodes.
• This strategy provides a pathway for developing durable, high-performance LIBs.
• Discrete microdomain bonding offers a new approach to binder design for high-capacity battery materials.