Metal–Organic Framework-Derived Co3O4@MWCNTs Polyhedron as Cathode Material for a High-Performance Aluminum-Ion Battery

Because of the unprecedented development and popularization of portable electronics, electric vehicles, and smart grid, rechargeable batteries have become one of the hottest topics within worldwide research for the past decade. Among all of the proposed nonlithium-based battery systems, rechargeable aluminum-ion batteries (RAIBs) are considered as a promising candidate due to aluminum's abundance and safety. Naturally, exploring compatible and high-performance cathode materials for RAIBs becomes a key issue for pushing RAIBs from lab-level to industrialization. In this work, we report a novel high-performance RAIB system using MOF-derived Co3O4@MWCNTs polyhedron composite as cathode. The well-defined morphology of MOF-derived Co3O4 and enhancement brought by MWCNTs allow Co3O4@MWCNTs polyhedrons to deliver an initial discharge capacity of ca. 266.3 mAh g–1, and the reversible specific capacity can reach 125 mAh g–1 at 100 mA g–1 over 150 cycles. The energy storage mechanism has been verified to be a reversible valence-change reaction between Co3O4 and Co. These findings can enlighten future research regrading MOF derivatives as advanced cathode materials for RAIBs.