The synthesis of ordered Sn–C composite microspheres and their mechanical properties

• A strategy to get stable and high active electrode materials is achieved.
• The structure of Carbon–tethered Sn composite spheres is designed originally.
• Mechanical stability of this Sn–C composite is strong enough for ultrasonic oscillations for 30 and 60 min.

A method for the fabrication of carbon–tethered Sn micro/nano composite spheres, a facile one-pot hydrothermal route followed by heat treatment in N2, is described. Heating of an aqueous solution of SnCl4 and resorcinol–formaldehyde (RF) to 85 °C for about 3 h in a 50 mL Teflon-lined stainless steel autoclave obtained the SnO2 encapsulated RF composite polymer spheres. Subsequent heat-treatment at 800 °C for 2 h under N2 atmosphere, the RF polymer was carbonized to spherical carbon spheres, whereas SnO2 reduced into nanosized Sn metal that was melted, migrated, and then deposited outside the carbon surface. Variation of the concentration of the two jointly dissolved chemicals and heat treatment temperature enables a variation of the size of the Sn particles. The ordered carbon–tethered Sn composite spheres were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetrical analysis, and mechanical stable process measurements by ultrasonic oscillations. The mechanical stability of Sn–C is strong enough for ultrasonic oscillations for 30 and 60 min.

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