Lamellar Nanocomposites of Manganese Dioxide and Reduced Graphene Oxide Nanosheets as Cathode Materials for Zinc-Ion Batteries

Zinc-ion batteries (ZIBs) have emerged as a compelling option for energy storage, owing to their cost effectiveness, high safety, environmental friendliness, and high energy density. In this work, superior Zn 2+ storage performance was achieved by constructing a lamellar MnO 2 /reduced graphene oxide (rGO) nanocomposite via a flocculation approach. This nanocomposite integrates the advantages of both components, consisting of alternately restacked unilamellar MnO 2 and rGO nanosheets with molecular-scale homogeneity, which affords high electrical conductivity, a large surface area with abundant active sites, and rapid Zn 2+ migration. As a result, the ZIB assembled with the MnO 2 /rGO nanocomposite delivered a specific capacity of 228 mAh g −1 at 50 mA g −1, far exceeding that of individual MnO 2 and rGO, thereby demonstrating that composite construction can significantly enhance the Zn 2+ storage abilities of MnO 2 nanosheets. This work highlights a promising strategy for designing high-performance ZIB cathodes and further advances the development of next-generation energy storage devices.