In‐Situ Growth of Mn₃O₄ Nanoparticles on Nitrogen‐Doped Carbon Dots‐Derived Carbon Skeleton as Cathode Materials for Aqueous Zinc Ion Batteries

Abstract

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 À 1 and 123.3 mAh g À 1 at current densities of 0.1 and 1.5 A g À 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.

Core–shell structures of Cu2O constructed by carbon quantum dots as high-performance zinc-ion battery cathodes

“…The R w value increases from 0.53 to 0.60 after the first cycle, which is due to the improved wettability between the electrolyte and electrodes, which can make the ion transport faster, showing good coulombic efficiency during the subsequent cycle. 38 After 3 cycles, the R ct value increases from 306.2 Ω to 863.1 Ω, which may be attributed to the formation of the CEI membrane obstructing the electron conduction. As shown in Fig.…”

Rice powder template for hausmannite Mn3O4 nanoparticles and its application to aqueous zinc ion battery

“…Prussian blue analogues (PBAs), manganese, vanadium, and organic species have been used to make ZIB cathodes. PBAs have a high potential (1.6–1.8V) but poor capacity (<100 mAhg −1 ) [ 9 ]. Although V-based cathode materials delivers high capacity and long cycling rate of performance, but they are costly, poisonous, and have a low voltage of operation (0.6–0.9 V).…”

Batch Synthesis of K-Doped α-MnO2 Nanorods as Cathode Materials for Aqueous Zinc-Ion Battery

“…Considering the inexpensive cost, safety, excellent ionic conductivity, and high energy density, − aqueous zinc-ion batteries (AZIBs) are highly attractive for next-generation energy storage equipment, such as roof energy storage in the suburbs and rural areas. It is essential to explore suitable zinc storage cathode materials for the development of AZIBs. − Manganese-based oxide has many advantages such as good theoretical capacity, low cost, low toxicity, and high working voltage, which makes it a competitive cathode material for zinc storage. − Manganese-based oxide cathode materials include MnO, − MnO 2 , − Mn 3 O 4 , − and other manganese oxides. − Among them, MnO 2 is appealing because of its tunnel structure, which is suitable for zinc storage.…”