Nano-silicon embedded in 3D honeycomb carbon frameworks as a high-performance lithium-ion-battery anode

Abstract

The fabrication of three-dimensional (3D) honeycomb carbon frameworks, incorporating embedded silicon (Si) nanoparticles (NPs), is successfully achieved through a facile method involving mixing, carbonization, and acid pickling. The as-prepared Si@PVPC composites exhibit excellent electrochemical performances due to reasons as follows. (1) Honeycomb channels supply enough space to accommodate the expansion of Si NPs and so structural integrity of 3D honeycomb carbon frameworks are maintained during lithiation/delithiation processes. (2) Honeycomb channels offers fast transfer paths for Li-ion diffusion. (3) 3D carbon frameworks afford reliable and stable electric contact points. As a result, Si@PVPC electrodes show a capacity of 1294.3 mAh g⁻¹ at 2 A g⁻¹ after 1400 cycles with a capacity retention of 85.5 %. Even at an ultrahigh current of 16 A g⁻¹, Si@PVPC electrodes still show a capacity of 619.6 mAh g⁻¹.