Fabrication of porous hollow glass microspheres

► Porous hollow glass microspheres are synthesized for use as battery additives. ► A simple fabrication method with commercial hollow glass microsphere precursors. ► 3M S38 and K25 etched in 1% hydrofluoric acid for 20 min. ► Sponge-like submicron pores or straight through micron pores created. ► Yields were 33–40%. Porous hollow glass microspheres have many uses, including porosity enhancers for lead-acid batteries. A fast, facile and high yield synthetic method for fabricating porous hollow glass microspheres with diameters around 45–55 μm is demonstrated. The process involves shaking commercially available hollow glass microspheres in dilute hydrofluoric acid for 20 min. This process yielded two pore morphologies by using different commercially available starting materials; sponge-like submicron pores etched from S38 microspheres, and straight through micron pore etched from K25. Yields were 33% and 40%, respectively. The simplicity of the reported fabrication technique has the potential to be scaled up for large scale production.