A core-shell MnO₂@Au nanofiber network as a high-performance flexible transparent supercapacitor electrode

Metal oxides have attracted great attention as active materials for supercapacitor devices because of their high energy densities. However, their application for transparent supercapacitors is limited due to their opaqueness. The challenge remains to fabricate flexible transparent metal oxide supercapacitor electrodes. Here, in this paper, we report a novel technique to fabricate flexible transparent core-shell MnO₂@AuNF network electrodes for flexible transparent supercapacitors. A high electro-optical performance AuNF network electrode (sheet resistance 9.58 Ω sq^-1 and optical transparency ∼93.13%) was fabricated using a scalable electrospinning process and thermal vacuum deposition technique. With the AuNF network electrode as a current collector, a hierarchal MnO₂ nanosheet was electrodeposited over the AuNF network, yielding a highly interconnected core-shell MnO₂@AuNF network electrode structure with high transparency (∼86%). The fabricated MnO₂@AuNF network electrode exhibited a high areal capacitance of 8.26 mF cm^-2 at 5 mV s^-1, along with high rate capability, long-term cycling stability, and excellent mechanical flexibility. Furthermore, the assembled flexible transparent supercapacitor device also showed high transparency (∼79%), a high energy density of 0.14 μW h cm^-2 at a power density of 4 μW cm^-2, along with excellent mechanical flexibility.