Advanced Interdisciplinary Research Center for Flexible Electronics;
Xidian University;
Xi’an 710071;
China;
Carbon/Carbon Composites Research Center;
Northwestern Polytechnical University;
Xi’an 710072;
China;
School of Science;
XI’AN University of Posts&Telecommunications;
Xi’an 710121;
China;
Carbon foam; Cu-Co oxides; Symmetric supercapacitors; Energy density;