Some experts have proposed a preparation method of inorganic all-solid WO3 electrochromic device. Wherein, the inorganic all-solid electrochromic device has a nickel oxide-zirconia-tungsten oxide stacked structure, and silver nanowires are spin-coated on the stacked structure.
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A Preparation Method of Inorganic All-solid WO3 Electrochromic Device
Step 1: Dissolve 1.224 g of nickel acetate in 10 mL of ethylene glycol monomethyl ether, add 0.5 mL of ethanolamine as a stabilizer, heat and stir at 60 °C in an oil bath for 2 h, then leave it to age for 24 h to obtain precursor A.
Step 2: Spin-coat the precursor A obtained in Step 1 on the cleaned glass substrate with transparent conductive electrodes, first at a low speed of 700 rpm for 10s, and then at a high speed of 3000 rpm for 30s. It needs 3 times of spin coating. The annealing temperature between each spin coating is 300 °C for 3 min, and then annealed in air at 300 °C for 1 h to obtain a nickel oxide film.
Step 3: Dissolve 1 mL of liquid zirconium acetate with a density of 1.279 g/mL in 2 mL of ethylene glycol monomethyl ether, then add 12 uL ethanolamine, stir at 500 r/min and let stand for 24 h for aging to obtain 0.6 mol/L of precursor solution B.
Step 4: Spin-coat the precursor solution B obtained in Step 3 on the nickel oxide film obtained in Step 2, with spin-coating speed of 6000 rpm, homogenization time of 40s, and homogenization times of 3 times. The annealing temperature between each homogenizer is 200 °C for 3 min, and then annealed at 200 °C for 1 h to obtain a laminated structure of zirconia and nickel oxide.
Step 5: Add the laminated structure of zirconia and nickel oxide obtained in Step 4 to the 0.1 mol KOH electrolyte, apply a voltage of 2.5 V for 1 min to make color, and fade under the condition of an external electric field, so that hydrogen ions enter and store in zirconia in the laminated structure with nickel oxide. The film is taken out and dried in a vacuum drying oven at 100 °C for 1 h.
Step 6: Dissolve 1 g of tungsten chloride powder in 10 mL of absolute ethanol, centrifuge and stir at 3000 r/min for 1 h in a centrifuge to obtain precursor solution C.
Step 7: Spin-coat the precursor solution C obtained in Step 6 on the stacked structure of hydrogen ion-containing zirconia and nickel oxide at a speed of 3000 r/min for 40 s. The wet film was allowed to stand in the air for 30 min, and then annealed at 200 °C for 1 h to obtain a nickel oxide/zirconia/tungsten oxide laminated structure.
Step 8: Spin-coat the silver nanowires on the laminate structure obtained in Step 7, at a low speed of 700 rpm for 10s and then at a high speed of 3000 rpm for 30s. It needs 2 times of spin coating. The annealing temperature between each spin-coating is 100 °C for 3min, and annealing at 100 °C for 1h, to obtain the inorganic all-solid WO3 electrochromic device.
