Screen-printed MXene for high-performance all-solid-state supercapacitors

Micro interdigitated supercapacitors (MSC) have attracted considerable attention due to their high-power density, fast charge-discharge capability, and excellent on-chip integration potential, making them promising candidates for wearable and flexible electronics. However, the practical performance of all-solid-state MSC is often limited by the low ionic conductivity and poor interfacial contact of conventional solid electrolytes. In this work, a high-viscosity Ti₃C₂T_x MXene ink suitable for screen-printing was developed as the electrode material, combined with a composite electrolyte composed of polyvinyl alcohol (PVA), polyethylene glycol (PEG), and glycerol (GL), to fabricate high-performance all-solid-state MSC. The PVA-PEG-GL gel electrolyte simultaneously delivers high ionic conductivity, excellent mechanical flexibility, and rapid self-healing capability, effectively improving electrode-electrolyte interfacial contact. Benefiting from efficient electron/ion transport, the fabricated devices exhibit high volumetric energy density and favorable balance between energy density and power density. This work provides an effective strategy for the scalable fabrication of flexible and miniaturized energy storage devices.