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 similar to 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. (C) 2014 The Electrochemical Society. All rights reserved.