A Free-Standing Polyaniline/Silicon Nanowire Forest as the Anode for Lithium-ion Batteries

Despite its high theoretical capacity, silicon anode has limited intrinsic conductivity and experiences significant volume changes during charge-discharge. To overcome these issues, facile metal-assisted chemical etching and in-situ polymerization of aniline are employed to produce a dense 1D polyaniline/silicon nanowire forest without noticeable agglomeration as a free-standing anode for lithium-ion batteries. This hybrid electrode possesses high cycling performance, delivering a stable capacity capped at 2 mAh cm(-2) for 346 cycles of charge-discharge. Maximum capacity of 2 mAh cm(-2) is also achievable at high-rate cell testing of 2 mA cm(-2), which cannot be obtained by the anode with plain silicon wafer and silicon nanowire only. The introduction of polyaniline on the silicon nanowire is shown to reduce the solid electrolyte interface (SEI) resistance, stabilize the SEI layer, further alleviate the effect of volume changes, and boost the conductivity of the hybrid anode, resulting in the high electrochemical performance of the anode.

Automated summary

In this study, a dense 1D polyaniline/silicon nanowire forest electrode is fabricated through facile metal-assisted chemical etching and in-situ polymerization of aniline. This hybrid electrode shows high cycling performance and stable capacity at various charge-discharge rates due to the reduction in solid electrolyte interface resistance and the increased conductivity.