Rational design of layer-by-layer assembled polypyrrole-based nanocomposite film for high-performance supercapacitor

In this work, a novel layer-by-layer assembled nanocomposite film of polypyrrole/graphene oxide with polypyrrole/nanocrystalline cellulose (PPy/GO|PPy/NCC) was fabricated. The number of layers is crucial to obtain high-performance supercapacitor. The electrochemical performances and structural changes of PPy/GO|PPy/NCC nanocomposite before and after reduction were compared. The structure and morphology of these bilayers were analyzed using Fourier-transform infrared spectroscopy and field emission scanning electron microscopy, respectively. The polypyrrole/nanocrystalline cellulose was attached to the polypyrrole/graphene oxide layer firmly without any apparent defects and cracks. Moreover, the prepared bilayer film gave a surface area of 42.88 m² g⁻¹, much higher than bilayer after reduction and a mesoporosity system, which is suitable for energy storage studies. This supercapacitor device delivered a high specific capacitance of 562.9 F g⁻¹ at 3 mV s⁻¹ with a maximum specific energy of 19.3 W h kg⁻¹ and a maximum specific power of 884.6 W kg⁻¹.