Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/13611
Título: | Di-ureasil hybrids doped with LiBF4: attractive candidates as electrolytes for "Smart Windows" |
Autor(es): | Barbosa, P. C. Fernandes, M. Silva, Maria Manuela Smith, Michael John Vilela, Sérgio M. F. Gonçalves, A. Olveira, M. C. Fortunato, E. Rego, R. Zea Bermudez, V. de |
Palavras-chave: | Solid polymer electrolyte Ionic conductivity Thermal analysis Electrocehmical satbility Organic/inorganic hybrid electrolytes Lithium trifluoroborate Ionic conductivity Cyclic voltammetry Electrochromic device lithium tetrafluoroborate |
Data: | 2011 |
Editora: | Esg |
Revista: | International Journal of Electrochemical Science |
Resumo(s): | The sol-gel process has been used to prepare hybrid electrolytes composed of a poly(oxyethylene) (POE)/siloxane hybrid network doped with lithium tetrafluoroborate (LiBF4) with compositions of n between ∞ and 2.5. In this context the lithium salt concentration is expressed in terms of the number of oxyethylene units in the organic component of the network per Li+ ion. Electrolyte samples with n ≥ 20 are thermally stable up to approximately 250 ºC. All the materials synthesized are semi-crystalline: in the composition range n ≥ 15 free crystalline POE exists and at 60 ≥ n ≥ 2.5 evidence of the presence of a crystalline POE/LiBF4 compound has been found. At n = 2.5 this latter crystalline phase coexists with free salt. The room temperature conductivity maximum of this electrolyte system is located at n = 10 (1.5x10-5 S cm-1 at 22 ºC). The electrochemical stability domain of the sample with n = 15 spans about 5.5 V versus Li/Li+. This new series of materials represents a promising alternative to the LiTFSI- and LiClO4-doped POE and POE/siloxane analogues. Preliminary tests performed with a prototype electrochromic device (ECD) comprising the sample with n = 8 as electrolyte and WO3 as cathodically coloring layer are extremely encouraging. The device exhibits switching time around 50 s, an optical density change of 0.13, open circuit memory of about 4 months and high coloration efficiency (106 cm2C-1 in the 3rd cycle). |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/13611 |
ISSN: | 1452-3981 |
Versão da editora: | The original publication is available at http://www.electrochemsci.org/ |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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IntJElectSci2011.ok.pdf | documento principal | 970,33 kB | Adobe PDF | Ver/Abrir |