A three-dimensional network structure Si/C anode for Li-ion batteries

A three-dimensional (3D) network structure Si/C anode with large pores is fabricated by using gelatin-PVA as carbon source. Silicon particles are embedded in the 3D network carbon skeleton. Gaussian calculation and FTIR test are employed to analyze the role of molecules interaction in forming the 3D network structure. The modified Si/C anode exhibits a reversible capacity of 830 mA h g⁻¹ after 100 cycles at 400 mA g⁻¹, and a capacity of 810 mA h g⁻¹ at 1.6 A g⁻¹ and 521 mA h g⁻¹ at 3.2 A g⁻¹. The 3D network structure with large pores benefits the electrolyte penetration, and the carbon coating layer avoids the direct contact of silicon particles with the electrolyte. The carbon layer can also help buffer the volume expansion of silicon, which is good to the cycling stability. All these aspects contribute to the enhanced electrochemical performance of the Si anode.