Interior design of hierarchical micro/nanostructures for enhancing energy storage ability of polyanilines through frozen interfacial polymerization

• Published in: Electrochimica acta Vol. 386; p. 138448
• Main Authors: Yang, Lifeng, Zhou, Yi, Xu, Xian, Shen, Yueying, Yan, Huafeng, Qin, Zongyi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Aniline; Charge storage ability; Charge transport; Diffusion rate; Electroactive materials; Electrochemical analysis; Electrode materials; Electron transport; Energy storage; Frozen interfacial polymerization; Hierarchical structure; Interior design; Ion diffusion; Morphology; Nanofiber; Nanofibers; Nanostructure; Oxidizing agents; Polyaniline; Polyanilines; Polymerization; Specific surface; Surface area; Nanofiber; Polyaniline; Frozen interfacial polymerization; Charge storage ability; Hierarchical structure
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2021.138448

Large specific surface area and hierarchically porous structure play critical roles in the preparation of high–performance electrodes for supercapacitor that strongly depended on the morphologies of electroactive materials. To impart large specific surface area and high ionic permeability, three kinds of hierarchical micro/nanostructures, i.e. sea urchin–like, flower–like and carpenterworm–like nanostructures, of polyaniline (PANI) products were constructed through simple frozen interfacial polymerization without any templates, special chemical regents or organic solvents. The formation of hierarchical micro/nanostructured PANIs were significantly affected by the interfacial area between aniline and oxidant ice layers and the adding order of aniline and oxidant, more detailedly, the number of the nanofibrous seeds formed at the early stage of polymerization and their ambient aniline concentration as well as the release rates of aniline and oxidant. Furthermore, the PANI with sea urchin–like micro/nanostructure exhibited the highest charge storage ability among all the electrode materials, more clearly, the specific capacitance of 716.8 F g–1 at a current density of 1 A g–1, rate retention of 96.9% from 1 to 20 A g–1, and cycling retention of 73.6% after 2000 cycles. The remarkable electrochemical performance can be ascribed to unique self–assembly of highly ordered nanofibers, making it possible to give full play to the advantages of PANI nanofibers including large electrode/electrolyte contact area, high charge transport along the nanofibers, accommodate volume changes extending in every direction during cycling, and fast electron transport and ion diffusion through porous structure. It is believed that such interior design and eco–friendly fabrication can offer an effective strategy to promote the electroactive properties of the PANI, and further development in the sensor– and energy–related fields.