Deposition and characterization of silicon thin film on stainless steel by electron beam evaporation

Silicon (Si) is a promising material as anode electrode because of its high theoretical capacity of 3579 mAh g-1 and low electrode potential (< 0.4 V vs. Li/Li+). In this paper, the Si thin film electrodes were fabricated by using electron beam evaporation on the stainless steel (SS) foil at room temperature. The structural and electro-chemical characterization were investigated for the Si thin film electrodes before and after annealing at 700 C. X-ray photoelectron spectroscopy analysis revealed that the annealed film layer consisted of SiOx containing about 30 at.% oxygen. The annealed Si thin film electrode resulted in improved electrochemical performance compared to as-deposited Si thin film electrode. The Si thin film electrode after annealing exhibited an initial discharge capacity of 2270 mAh g(-1), and sustained excellent cycle stability with retention capacity about 95 % for 100 cycles at 0.5 C-rate. The improvement in cyclability for the annealed Si thin film electrode can be attributed to the enhanced adhesion of Si thin film to SS substrate through interdiffuion at the Si/SS interface owing to the post-annealing process.