The Dispersion Effect of Fumed Silica in Lithium-ion Battery Electrolytes
Fumed silica, through its high specific surface area (50-400 m²/g) and three-dimensional network structure, forms a physical support network in the electrolyte, effectively adsorbing harmful substances such as free HF and H₂O. Its dispersion involves three stages: wetting, deagglomeration, and stabilization:
Wetting: Surfactants are added to reduce surface tension and improve compatibility with the electrolyte.

Deagglomeration: High-shear dispersion equipment (such as ultrasonic or ball mill) is used to disperse agglomerates to below 100 nm.

Stabilization: Electrostatic repulsion or steric hindrance prevents particle re-agglomeration.
Stabilization Mechanism for Electrolyte Performance
Interface Protection: Promotes the formation of a LiF-rich SEI film, improving the stability of the lithium metal anode (capacity after 3000 cycles). (Retention rate 83.6%)

Self-cleaning function: Adsorbs HF in the electrolyte through surface silanol groups, inhibiting side reactions.
Rheological control: Forms a thixotropic network to prevent electrolyte stratification.
Application precautions:
Dispersion process: Indirect method (mother liquor method) is recommended to avoid potting blockage caused by direct mixing.
Concentration control: High solids content dispersion can enhance shear force, but viscosity and stability need to be balanced.
Modification treatment: Hydrophobic fumed silica (such as methyl-modified) is more suitable for non-polar electrolyte systems.