3-mercaptopropyltriethoxysilane templated etching of aluminum foil for high-capacitance electrolytic capacitors

Aluminum electrolytic capacitors are widely used in electronics due to their high volumetric capacitance and cost-effectiveness. However, their performance is often Limited by non-uniform tunnel formation and excessive tunnel merging during conventional aluminum foil etching processes. In this study, we introduce 3-mercaptopropyltriethoxysilane (MPTES) as a templating agent to control the nucleation and growth of etched tunnels in aluminum foil. The porous MPTES self-assembled film effectively guides the formation of uniform tunnels, significantly improving their distribution homogeneity and dimensional consistency. This optimization enhances the foil’s specific surface area, yielding an 8.3% increase in specific capacitance under optimal conditions (1% MPTES, 5 min treatment). Our findings provide a practical and scalable approach to improve etching processes for high-performance aluminum electrolytic capacitors.