High-Performance 3D Flower-Morphology NiO@C composite cathode material for Rechargeable Aluminum-Ion batteries

The flower-like structure NiO@C composite cathode materials show high discharge capacity and better cycling stability than NiO . NiO possesses a high theoretical capacity, but its poor conductivity and significant volume changes during the redox process lead to severe electrochemical performance degradation, limiting its applications. In this study, flower-like structure NiO@C composite materials were synthesized via a hydrothermal method. The particle size of the material is approximately 10–16 μm, with a well-defined morphology of carbon material composite. Al-NiO@C batteries were constructed using NiO@C cathode and subjected to electrochemical performance testing. The initial discharge capacity of NiO@C composite material at a current density of 200 mA g −1 is 126 mA h/g, and even after 150 cycles, it retains a discharge specific capacity of 54 mA h/g. In contrast, the pure NiO exhibits an initial capacity of only 49 mA h/g, which decreases to 23 mA h/g after 150 cycles. The cycling stability of NiO@C material is significantly better than that of NiO alone. This improvement is attributed to the enhanced conductivity of NiO material by the addition of carbon material, which provides improved electron/ion transport properties. Additionally, the inclusion of carbon material helps alleviate the volume changes of NiO during the reaction process, thereby enhancing the overall electrochemical performance of Al-NiO batteries.