Polyaniline nanowire arrays on biomass-derived carbon nanotubes with typha longbracteata for high-performance symmetric supercapacitors

Biomass-derived carbons have great competitive advantages in supercapacitor because of their structure diversity, excellent electrochemical performance and environmental protection. In this paper, the biomass-derived carbons nanotubes (BCNs) are fabricated by carbonization of typha longibracteata (TL). Then, the polyaniline nanowire arrays (PANI NWAs) are vertically grown on the TLBCNs to obtain the PANI NWA/TLBCNs electrode by in-situ polymerization. The prepared TLBCNs have a length of ~200 μm and a diameter of ~5 μm, and PANI NWAs have a length of 400 nm. The electrode appears a specific capacitance of 565.9 F·g⁻¹ (at 1 A·g⁻¹). The symmetric supercapacitor has an energy density of 25.4 Wh·kg⁻¹ (at the power density of 1.58 kW·kg⁻¹). Its specific capacitance is retained 87.9 % (after 5000 cycles at 1 A·g⁻¹). Therefore, the PANI NWA/TLBCNs is a hopeful electrode material for the energy storage devices.