Key Laboratory of Colloid and interface Chemistry Ministry of Education School of Chemistry and Chemical Engineering and State Key Laboratory of Crystal Materials Shandong University Jinan 250100 Shandong China;
Department of Science and Technology of Shandong Province Jinan 250100 Shandong China;
School of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 Shandong China;
College of Materials Science and Engineering Qingdao University of Science and Technology Qingdao 266042 Shandong China;
Fe7Se8; Hierarchical structure; Nanorod bundles; Sodium-ion batteries; Oleylamine;