Performance study of bimetallic Mn-Zn porous flower-like nanosheets as supercapacitor positive electrode materials

As environmental and carbon emission issues become increasingly severe, electrochemical energy storage systems have gained attention. Compared to traditional supercapacitors, zinc-ion hybrid capacitors (ZIHCs) are not only environmentally friendly but also cost-effective. MnO 2 , with its low cost, eco-friendliness, high theoretical capacity, and stable crystal structure, is considered a promising positive electrode material. In this study, the morphology of MnO 2 was optimized using electrodeposition. During cycling, zinc ions reversibly intercalate and extract from MnO 2 , forming a cactus-like nanoflower structure. This structure is loose and porous, providing ample reaction space for active materials. The assembled device exhibits excellent performance in both energy density (85.68 Wh kg −1 ) and stability (91.60 %).