SiO -based graphite composite anode and efficient binders: practical applications in lithium-ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Silicon dioxide (SiO2)-graphite composite anodes are investigated for high specific capacity in lithium-ion batteries.
• Efficient binders are crucial for maintaining the electronic and mechanical integrity of these composite anodes.

Purpose of the Study:

• To compare the performance of water-soluble styrene butadiene rubber (SBR) and polyacrylic acid (PAA) binders in a 15% SiO2-graphite composite anode.
• To evaluate binder effects on electrode properties, electrochemical performance, and practical battery applications.

Main Methods:

• Fabrication of SiO2-graphite composite anode electrodes using SBR and PAA binders.
• Measurement of peeling strength, first coulombic efficiency, and discharge specific capacity.
• Electrochemical impedance spectroscopy (EIS) and rate performance testing.
• Evaluation in half-cell (coin) and high-voltage pouch battery configurations.

Main Results:

• SBR binder yielded a first coulombic efficiency of 83.6% and a discharge specific capacity of 626.5 mA h g⁻¹, while PAA binder achieved 81.2% and 636.1 mA h g⁻¹.
• SBR binder showed better electron and ion transfer, indicated by EIS and rate performance.
• PAA binder resulted in lower swelling (7.49% vs. 9.56%) and better cycle performance in high-voltage pouch batteries at the 450th cycle.

Conclusions:

• While SBR binder facilitates charge transfer, PAA binder offers improved stability and cycle life in practical high-voltage lithium-ion battery applications.
• The choice of binder significantly impacts the performance and durability of SiO2-graphite composite anodes.