A Silicon nanowire (SiNW) array inserted into flexible poly-dimethylsiloxane (SiNW array/PDMS) composite structure as anode with high capacity and long-term cycling stability is synthesized by a cost-effective and scalable method. In this structure, the aggregation and fracture of SiNWs are alleviated by the flexible PDMS skeleton. Act as the main active component, the SiNWs are coated by loose SiO₂ shells. These loose SiO₂shells not only provide space for the large volume changes of SiNW, but also react with the electrolyte and form the stable protective layer during the processes of the lithiation and delithiation. These two functions could improve the cycling stability and columbic efficiency of the SiNWs. The as-obtain flexible SiNW array/PDMS composite structure exhibits excellent long-term cycling stability with a specific capacity of 887.2 mA·h·g⁻¹ and capacity retention of ∼83.4% over 350 cycles at 0.5 C rate compared with the fifteenth cycle. The design of this new structure provides a potential way for developing other functional composite materials.

Electrochimica Acta, 2015

The images for the surface of Si/SiO₂ nanowire array (a) the optical image of SiNW array on the surface of the Sn substrate; (b) the side view SEM image of Si/SiO2 nanowire array; (c) the SEM image of as-prepared SiNWs coated by SiO2 shell; (d) TEM image of the single Si/SiO2 core/shell nanowire, inset is the relative EDX spectrum and e SAED pattern.