Flexible Transparent Molybdenum Trioxide Nanopapers for Supercapacitors

Abstract

Free-standing paper-like film with excellent transparency and flexibility holds great potential to serve as a transparent electrode for wearable electronics and energy storage. Transition metal oxide have shown their great potential for energy storage due to their high capacitance and stability. Nevertheless, the fabrication of ultrathin transparent paper electrode via the assembly of 1D transition metal oxide nanostructure has never been reported. Orthorhombic molybdenum trioxide (α-MoO3), transition metal oxide with layered structures, has been recognized as a promising electrode for energy storage. In this talk, I will talk about the fabrication of flexible and transparent MoO3 nanopapers via assembly of ultralong molybdenum trioxide nanobelts (MoO3 NBs) and their application for high-performance supercapacitor electrodes. The well-dispersed, ultralong MoO3 NBs with an average length of 200 µm have been synthesized via a hydrothermal method. A flexible transparent molybdenum trioxide nanopaper via the assembly of these ultralong nanobelts displays an excellent average transmittance of 90% in the visible region. Significantly, the freestanding nanopaper electrode delivers an outstanding specific capacitance of 1198 F g-1 at 2 mV s-1, which is just slightly below the theoretical value of molybdenum trioxide (1256 F g-1). The excellent specific capacitance can be ascribed to the efficient ion diffusion in the 3D structure and the very thin nanobelts, as well as the reduced distance of electron transport from transparent nanopaper electrode to current collector. The nanopaper-based supercapacitor device also shows an excellent long-term stability performance over 20,000 cycles with a retention rate of 96.5%. Figure 1