Amorphous ZnO‐Fe 2 O 3 ‐P 2 O 5 Cathode Material for Zinc‐Ion Batteries and its Modification with Carbon Dots

Abstract Aqueous zinc‐ion batteries (AZIBs) have garnered extensive attention due to their high safety and low‐cost nature. However, the advancement of AZIBs is hindered by the low capacity and high cost of cathode materials. Amorphous materials, with their compositional and structural versatility, enable the optimization of their properties to meet specific requirements. In this work, amorphous xZnO‐(50‐x)Fe 2 O 3 ‐ 50P 2 O 5 (x = 15, 20, 25, 30, 35, 40, mol%) cathode materials were employed in AZIBs to investigated the changes in the internal structure of the glass during Zn substitution for Fe and their impact on electrochemical performance. The materials were characterized by XRD, FTIR, SEM, and EDS. Acid‐resistance and density tests were carried out to analyze the compactness of the materials. Moreover, bulk resistivity tests were used to explore the impact of variations in composition on conductivity. Electrochemical performance was evaluated through electrochemical impedance spectroscopy and galvanostatic charge‐discharge tests. Additionally, graphene composite technology was employed to enhance electrical performance. When the graphene content ratio reached 2, the electrochemical performance was optimized, exhibiting high cycle stability (capacity stabilized at 32.83 mAh/g after 400 cycles at 50 mA/g with Coulombic efficiency approaching 100%). This indicates a promising new glass cathode for future AZIBs.