Fig. 2From: Free-Standing Selenium Impregnated Carbonized Leaf Cathodes for High-Performance Sodium-Selenium BatteriesSEM images of the R800 a upper surface and back surface and b cross-sectional view. c Magnified SEM image of the carbon sheet in the sponge layer of the R800A. d FESEM image of the cross section. e Magnified FESEM image. f HRTEM image of the Se-R800ABack to article page