MOFs and Three-Dimensional Device Architectures for Sustainable Hybrid Supercapacitors

The demand for sustainable energy storage technologies has generated enormous research interest in hybrid supercapacitors, which combine the high power density of supercapacitors with the favorable energy density of battery-type systems. Metal–organic frameworks (MOFs) are promising electrode candidates in energy storage due to their tunable compositions, high degree of porosity, various active sites, and their versatile chemistry. However, these fascinating properties of MOFs do not necessarily translate into high performance in hybrid supercapacitor devices, as their performance largely depends on the configuration of the electrodes, the interfacial contact, and the mass-transport pathways. One appealing approach to address these challenges is the development of 3D electrode architectures, in which MOFs and derivatives are embedded in interconnected conductive frameworks and hierarchical pore networks with favorable electron transport, electrolyte infiltration, and ion diffusion. This review critically assesses the progress on MOF-based 3D architectures for sustainable hybrid supercapacitors, focusing on MOF composition, defect engineering, MOF-derived materials, conductive scaffolds, hierarchical porosity, and device architecture. We focused on green synthesis, bio-sourced ligands, bio-based carbon, low-energy processes, and scaling up fabrication. The sustainability–performance relationships and the difficulties associated with the implementation of the laboratory-scale architectures into actual devices are critically analyzed.