Tailoring Al-MOF-Derived Carbon for Balanced Electrochemical Performance in Both Negative and Positive Potential Windows via Carbonization-Enabled Structural Regulation

As urgent demands increase in energy-grid systems, supercapacitors have been further documented as highly promising energy-storage technologies across a range of applications owing to their high-power density, rapid charge–discharge capabilities, and prolonged endurance life. Porous carbon-based materials, particularly those derived from metal–organic frameworks (MOFs), are prominent candidates for supercapacitor electrode materials owing to their customizable inner-pore structures and superior electrochemical properties. In this work, we systematically manipulate the carbonization temperature (700–900 °C) of Al-NDC-MOF to tailor the hierarchical pore structure, defect density, and surface chemistry of the resulting porous carbons (AC-Al-NDC- x ), aiming to unravel the structure–performance–device correlations required for stable dual-ion storage. Systematic characterization reveals that carbonization temperature plays a crucial role in regulating pore structure hierarchy, defect density, and surface functional groups. As a result, the optimized sample (AC-Al-NDC-800) exhibits balanced electrochemical performance, enabling its application as both positive and negative electrodes in symmetric and asymmetric two-electrode devices. This behavior is attributed to the synergistic effect of micropores for charge storage, mesopores for ion transport, and appropriate surface functionalities for interfacial stability. Although the achieved energy density and cycling stability are comparable to previously reported porous carbon systems, this work highlights a rational design strategy for balancing pore structure and surface chemistry to achieve stable dual-ion storage under practical two-electrode conditions.