Interfacial Synthesis and Supercapacitive Performance of Hierarchical Sulfonated Carbon Nanotubes/Polyaniline Nanocomposites

The novel hierarchical PANI/sMWCNT nanocomposites were synthesized through the interfacial polymerization method in the presence of the sulfonated multiwalled carbon nanotubes (sMWCNT), and the effect of oxidant content on the chain structure of PANI, the microstructure, and supercapacitive performance of the composites were investigated systematically. FT-IR spectra revealed the presence of π–π interactions between PANI and sMWCNT, and the charge-transfer composites were formed. It was found that more charge-transfer composites developed when the oxidant was at a lower content. The FESEM images indicated that the morphology of the composites changed significantly with varying oxidant content. It could be seen from electrochemical tests that the supercapacitive performance of the nanocomposites was influenced markedly by their microstructure, the content, and the oxidation degree of PANI. When the oxidant content was high at 2 for the APS/aniline mole ratio, the composite had high specific capacitance with 431.3 F/g but showed poor rate performance and charge/discharge stability. At a lower oxidant content with 1/6 of the APS/aniline mole ratio, the specific capacitance of the composite decreased to 216.6 F/g; nevertheless, it possessed superior rate performance with 82.8% capacitance retention at 10 A/g and excellent cyclability with just 11.2% capacitance loss after 2000 cycles

Ultrafine V₂O₃ Nanowire Embedded in Carbon Hybrids with Enhanced Lithium Storage Capability

Compared to other transition metal oxides, V₂O₃ with a higher conductivity has attracted intense attention in energy storage fields. To further improve its rate capability and cycling stability, we demonstrate the synthesis of carbon-encapsulated ultrafine V₂O₃ nanowires (V₂O₃@C NWs) hybrids. The optimized V₂O₃@C NWs hybrids, when applied as anode materials for lithium-ion batteries (LIBs), deliver a high specific capacity of 985 mA h g^–1 at 100 mA g^–1, which is higher than V₂O₃ nanoparticles (V₂O₃ NPs, 248 mA h g^–1) and even 2.6 times higher than graphite anodes. More significantly, they also exhibit remarkably enhanced rate capability (519 mA h g^–1 at 5000 mA g^–1) and long cycle life (860 mA h g^–1 at 1000 mA g^–1 after 300 cycles). Such fascinating electrochemical performance is mainly attributed to the uniform coating of carbon and their ultrafine nanostructure, which can further improve the conductivity and enrich the electrochemical active sites