Fig. 4From: Free-Standing Selenium Impregnated Carbonized Leaf Cathodes for High-Performance Sodium-Selenium Batteriesa XRD patterns and b Raman spectra. c N2 adsorption/desorption isotherms and d pore-size distribution curves obtained by the DFT method. e Thermogravimetric analysis. f XPS spectra of Se in the Se-R800ABack to article page