Electrochromic device composed of a Di-Urethanesil electrolyte incorporating lithium triflate and 1-Butyl-3-Methylimidazolium chloride

• Autor(a) principal: Goncalves, Maria Cristina
• Data de Publicação: 2020
• Outros Autores: Pereira, Rui Francisco Gonçalves Pinto Fernandes, Alves, Raquel Diana Carneiro, Nunes, Silvia C., Fernandes, Mariana, Goncalves, Helena M. R., Pereira, Sonia, Silva, Maria Manuela, Fortunato, Elvira, Rego, Rosa, de Zea Bermudez, Veronica
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/73067
• topic: di-urethanesil; sol-gel; lithium triflate; 1-butyl-3-methylimidazolium chloride; electrochromic device; Ciências Naturais::Ciências Químicas; Science & Technology

A di-urethane cross-linked poly(oxyethylene)/silica hybrid matrix [di-urethanesil, d-Ut(600)], synthesized by the sol-gel process, was doped with lithium triflate (LiCF3SO3) and the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid. The as-produced xerogel film is amorphous, transparent, flexible, homogeneous, hydrophilic, and has low nanoscale surface roughness. It exhibits an ionic conductivity of 3.64 x 10(-6) and 5.00 x 10(-4) S cm(-1) at 21 and 100 degrees C, respectively. This material was successfully tested as electrolyte in an electrochromic device (ECD) with the glass/ITO/a-WO3/d-Ut(600)(10)LiCF3SO3[Bmim]Cl/c-NiO/ITO/glass configuration, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. The device demonstrated attractive electro-optical performance: fast response times (1-2 s for coloring and 50 s for bleaching), good optical memory [loss of transmittance (T) of only 41% after 3 months, at 555 nm], four mode modulation [bright mode (+3.0 V, T = 77% at 555 nm), semi-bright mode (-1.0 V, T = 60% at 555 nm), dark mode (-1.5 V, T = 38 % at 555 nm), and very dark mode (-2.0 V, T = 11% and -2.5 V, T = 7% at 555 nm)], excellent cycling stability denoting improvement with time, and high coloration efficiency [CEin = -6727 cm(2) C-1 (32th cycle) and CEout = +2794 cm(2) C-1 (480th cycle), at 555 nm].