In‐Situ Growth of Mn 3 O 4 Nanoparticles on Nitrogen‐Doped Carbon Dots‐Derived Carbon Skeleton as Cathode Materials for Aqueous Zinc Ion Batteries

• Published in: ChemSusChem Vol. 15; no. 6; p. e202102390
• Main Authors: Song, Tian‐Bing, Huang, Zun‐Hui, Niu, Xiao‐Qing, Zhang, Xi‐Rong, Wei, Ji‐Shi, Xiong, Huan‐Ming
• Format: Journal Article
• Language: English
• Published: Germany 22.03.2022
• Subjects: Mn3O4; carbon dots; nanocomposite; zinc ion battery; cathode material
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.202102390

Mn 3 O 4 is a promising cathode material for aqueous zinc ion batteries (ZIBs) which is a new type of low cost, eco‐friendly, high security energy storage system, while those previously reported electrochemical capacities of Mn 3 O 4 are far from its theoretical value. In this work, Mn 3 O 4 nanoparticles and nitrogen‐doped carbon dots (NCDs) are synthesized together through an in‐situ hydrothermal route, and then calcined to be a nanocomposite in which Mn 3 O 4 nanoparticles are anchored on a nitrogen‐doped carbon skeleton (designated as Mn 3 O 4 /NCDs). Although the carbon content is only 3.9 wt.% in the Mn 3 O 4 /NCDs, the NCDs‐derived carbon skeleton provides an electrically conductive network and a stable structure. Such a special nanocomposite has a large specific surface area, plenty of active sites, excellent hydrophilicity and good electronic conductivity. Owing to these structural merits, the Mn 3 O 4 /NCDs electrode exhibits a preeminent specific capacity of 443.6 mAh g −1 and 123.3 mAh g −1 at current densities of 0.1 and 1.5 A g −1 in ZIBs, respectively, which are far beyond the bare Mn 3 O 4 nanoparticles synthesized under the similar condition. The electrochemical measurement results prove that carbon dots, as a new type of carbon nanomaterials, have strong ability to modify and improve the performance of existing electrode materials, which may push these electrode materials forward to practical applications.