Interface Engineering Strategy of Polydopamine-Decorated rGO/Carbon Fiber Electrodes toward Robust Sweat-Activated Yarn Supercapacitors.

With its superior mechanical flexibility and unique one-dimensional structure, fiber-shaped supercapacitors are regarded as a promising microenergy storage unit for wearable electronics. However, the potential toxicity of its electrolyte significantly restricts its application. Herein, based on the interface engineering regulation strategy, this study designed and prepared polydopamine-modified reduced graphene oxide (rGO/PDA) composite materials, and successfully constructed a high-performance sweat-activated yarn supercapacitor (SYSC). Benefiting from the excellent interfacial wettability and abundant electrochemically active sites of rGO/PDA composites, SYSC exhibits outstanding electrochemical performance in an artificial sweat environment, effectively eliminating the potential safety hazard caused by electrolyte leakage. At a power density of 120-3000 μW cm-2, SYSC exhibits a high energy density of 0.57-12.1 μWh cm-2 and remains highly stable after large deformation. This work provides an effective way to fabricate biofriendly, safe, and controllable flexible supercapacitors.