Characterization of Nano Silicon on Nanopillar-Patterned Nickel Substrate for Lithium Ion Batteries

Abstract

To enhance the electrochemical characteristics of Si anodes for use in secondary batteries, a Ni-based Si-pattern substrate is evaluated. This Ni-based Si pattern is fabricated by a combination of nanoimprint lithography, plasma-enhanced chemical vapor deposition, and electroforming processes; its micro-morphology is determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The discharge capacity of this pattern is found to be ∼2552 mAh g−1 after the 1st cycle at 1.0 C rate, which represents a suitably high current density. After 100 cycles, the pattern exhibits a 732 mAh g−1 charge capacity and 47% charge capacity retention. This Ni-based Si pattern therefore possesses an excellent rate capability, with the electrode having a discharge capacity of 412 mAh g−1, despite a relatively rapid 10 C rate. Moreover, the anode cell maintains its high capacity, even after 100 cycles, because of the high electrical conductivity of Ni, the regularity of the pattern structure, and the nanoscale Si.