An integrated electrochromic supercapacitor based on nanostructured Er-containing titania using an Er(III)-doped polyoxotitanate cage

The novel heterometallic polyoxotitanate cage [Ti8O7(OEt)(21)Er] can be used as a single-source precursor for the formation of nanostructured Er-containing titania materials (Er@TiO2). Based on the electrochromic properties and lithium ion storage capacity of Er@TiO2, an integrated bifunctional EC supercapacitor has been designed.