Nano-silicon composites using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) as elastic polymermatrix and carbon source for lithium-ion battery anode

Abstract

Nano-silicon composites, Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and Si/C, were prepared by an in situ chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) with nano-Si particles in a PSS aqueous solution and subsequent carbonization of Si/PEDOT:PSS, respectively. The nano-Si particles were embedded in a shapeless PEDOT:PSS matrix and amorphous carbon in the corresponding composite. Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) measurements revealed that 2.66 wt% of the element sulfur was doped in the carbon matrix for Si/C composite. Both the Si/PEDOT:PSS and Si/C composite electrodes exhibited higher initial coulombic efficiency and better cycling performance than the bare nano-Si anode. The Si/C composite showed the best electrochemical performance, retaining a specific capacity of 768 mA h g⁻¹ and a Coloumbic efficiency of 99.2% after 80 cycles, with a very small initial capacity loss of 2.80% and a capacity fade of 0.48% per cycle.