Abstract
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Fiber-shaped micro-supercapacitors (micro-SCs) have attracted enormous interest in wearable electronics due to high flexibility and weavability. However, they usually present a low energy density because of inhomogeneity and less pores. Here, we demonstrate a microfluidic-directed strategy to synthesize homogeneous nitrogen-doped porous graphene fibers. The porous fibers-based micro-SCs utilize solid-state phosphoric acid/polyvinyl alcohol (H3PO4/PVA) and 1-ethyl-3-methylimidazolium tetrafluoroborate/poly(vinylidenefluoride-co-hexafluoropropylene) (EMIBF4/PVDF-HFP) electrolytes, which show significant improvements in electrochemical performances. Ultralarge capacitance (1132 mF cm?2), high cycling-stability, and long-term bending-durability are achieved based on H3PO4/PVA. Additionally, high energy densities of 95.7-46.9 µWh cm?2 at power densities of 1.5-15 W cm?2 are obtained in EMIBF4/PVDF-HFP. The key to higher performances stems from microfluidic-controlled fibers with a uniformly porous network, large specific surface area (388.6 m2 g?1), optimal pyridinic nitrogen (2.44%), and high electric conductivity (30785 S m?1) for faster ion diffusion and flooding accommodation. By taking advantage of these remarkable merits, this study integrates micro-SCs into flexible and fabric substrates to power audio-visual electronics. The main aim is to clarify the important role of microfluidic techniques toward the architecture of electrodes and promote development of wearable electronics.
Original language | English |
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Article number | 1702493 |
Journal | Advanced Functional Materials |
Volume | 27 |
Issue number | 36 |
DOIs | |
Publication status | Published - 26 Sept 2017 |
Externally published | Yes |
Keywords
- fibers
- micro-supercapacitors
- microfluidics
- nitrogen-doped graphene
- porous structures
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics