Highly Stretchable Polymer Binder Engineered with Polysaccharides for Silicon Microparticles as High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Silicon anodes offer high capacity for lithium-ion batteries but suffer from pulverization due to large volume expansion during cycling.
• Microsized silicon particles are particularly prone to disintegration, limiting their practical application.

Purpose of the Study:

• To develop a novel binder system to mitigate the volume expansion challenges of microsized silicon anodes.
• To enhance the cycling stability and performance of silicon-based lithium-ion batteries.

Main Methods:

• Engineering highly stretchable polymer binders with helical polysaccharides.
• Fabricating microsized silicon electrodes utilizing the novel binder.
• Conducting electrochemical performance tests, including cycling stability and Coulombic efficiency.
• Assembling and testing full cells with commercial LiCoO2 cathodes.

Main Results:

• The engineered binder demonstrated excellent stretchability and adhesion, effectively buffering strain and preventing pulverization of silicon fragments.
• Microsized silicon electrodes achieved a high initial Coulombic efficiency of 91.8% and maintained stability over 300 cycles.
• Full cells with LiCoO2 cathodes exhibited a high areal capacity of 3.02 mAh cm⁻² and superior stability for 100 cycles.

Conclusions:

• Highly stretchable polymer binders are effective in overcoming the volume expansion limitations of microsized silicon anodes.
• This approach significantly improves the cycling stability and energy density of silicon-based lithium-ion batteries.
• The findings pave the way for the practical implementation of high-capacity microsized silicon anodes in next-generation batteries.