Controlled synthesis of hollow Si-C microspheres and its potential as an anode material in lithium-ion batteries

Hollow structure has great potential in lithium-ion batteries, especially in Si-based anode materials. Unlike the usual templating process, here, we report a template-free synthetic strategy to build hollow microspheres of Si-C hybrid materials, which combines an in-situ polymerization process to form precursor and magnesiothermic reduction towards the inner cavity. As a result, the hollow Si-C microspheres exhibit improved cycling performance (768.7 mA h g ⁻¹ after 100 cycles at 0.84 A g ⁻¹) and good rate capability (497.1 mA h g ⁻¹ at 8.4 A g ⁻¹ ) when used as an anode material in lithium-ion batteries. This work provides a controllable and industrially-scalable operation based on cheap source to synthesize hollow Si-C hybrid materials, which combines the advantage of hollow structure and carbon matrix to achieve better electrochemical performance than the solid one.