Engineering oxygen vacancies in mesoporous TiO2 effectively enhanced its ability to trap polysulfides and simultaneously propelled the redox conversion of polysulfides.
Cycling tests for LaCoO 3 -based symmetric supercapacitors were carried out. The change in the valence state of Co in the electrode surface active material, LaCoO 3 , before and after the cycling test was investigated by X-ray photoelectron spectroscopy.