Optimization parameters of NiO films by DC magnetron sputtering and improvement of electrochromic properties by a mixed electrolyte

It is well accepted electrochromic layer and electrolyte both are key segments in electrochromic devices (ECDs). In this work, research on the optimized experimental parameters of NiO films via DC magnetron sputtering was studied firstly, it was found sputtering power 200 W, O2/Ar 6:50 and deposition 5 min is an energy saving and excellent preparation method. The prepared NiO film shows superior transmittance modulation 61.64% in KOH electrolyte and long-term stability in LiClO4/PC electrolyte with little change after 1300 cycles. Based on their respective strengths, a new hybrid electrolyte consisting the ratio 3:1 of KOH and LiClO4/PC was prepared, and it was proven to improve NiO film's electrochromic properties in optical performance increased to 33.41% and peak current density decreased only 24% after 1500 cycles. The results shed light on exploring a novel method to get high electrochromic performance by study of electrolyte.