Hybrid Transparent PEDOT:PSS Molybdenum Oxide Battery-like Supercapacitors

We report fabrication of flexible all-solid-state transparent electrochromic patterned microsupercapacitors based on two-dimensional layered nanostructured molybdenum oxide (MoO_3-x)/poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT:PSS) nanocomposite electrodes. Exceptional electrochemical performance of the transparent microsupercapacitors includes fast kinetics and response times, high specific capacitances (up to 79.2 C/g, 99 F/g, and 2.99 mF/cm²), and Coulombic efficiencies of 99.7% over 2500 cycles. Such exceptional performance is attributed to the synergistic effects of PEDOT:PSS providing high electrical conductivity and high charge storage capacity along with its segregated interfacial nanostructure facilitating the intercalation of the ionic species, H⁺(Na⁺, K⁺) and SO₄ ^2-, into the high surface area tunnel structure of the 2D MoO_3-x nanosheets. Supercapacitors using MoO_3-x PEDOT:PSS electrodes exhibit optical transmittance above 70% (λ = 380-730 nm).